AMATEUR ASTRONOMY Published Monthly by the American Amateur Astronomical Association Vol

AMATEUR ASTRONOMY Published Monthly by the American Amateur Astronomical Association Vol. 4-No. 5 May, 1938 Ten Cents

Some Activities of an Amateur J. RUSSELL SMITH, Director Smith's AstronouicaI 0bseratory

ed with many interesting spots of the sky. After my initial attempts at photo- grapfly wtfl the 2½-inch, I oecame in- cerested in lantern slide making. As a result, I made ovér 100 astronomicai slides. Most of them were "via'S the i-e- pru duction method. This group of slides Is divided into the following units: lunar, solar system, nebulae, and comets, and miscellaneous. beveral hundred slides for the various sciences, which I teach, were also made. The astronomical slides are found to be useful in help- My little 8-inch Newtonian is situated ing to stimulate interest in astronomy. on the High Plains of Tèxas-out where i lind them most useful in teaching gen- we are blessed with black skies which are eral science. (For a brief discussLii of very favorable for astronomical observa- my method of arousing iñterest in astro- tions. However, thé high winds and nomy, I refer you to The Sky for May dust storms are quite objectional at 1937, page 28-29) . In passing, I should times. like to mention the fact that the art of The 8-inch aluminized pyrex mirror lantern slide making is not dilficuit and has an excellent figure and a focal length good sudes can be made by the amateur of 60 inches. A Ramsden ocular of two pnotographer at a price much less than inch focal length (30X) gives a wide field the cost of commercial elides. and is very suitable for viewing wide The work of my little observatory is clusters and comets. It is also very principally the observation of variable useful in locating and observing certain stars. However, my time is limited and variable stars. Other powers obtained consequently my observations do not run are 60X, 120X, 180X, 240X and at times into large numbers. I also indulge in I am able to use an cicular of '/sinch planetary observations. In June 1937, focal length which gives a power of I made several drawings of the planet 480X. Mars. I found that more detail could be The mount is by Harry Lee Armiger seen by observing the planet at about of Detroit. It is all-weather heavy and 7:30 P.M., C.S.T. (before sundown). I rigid, which helps to make observing a also found that a power of 120X gave pleasure in this windy section of the better contrast than higher powers. Bet- country. The mount is equipped with ter seeing could, be had by observing the circles, verniers and slow motion in both well-known planet at this time with full right ascension and declination. The aperture than by observing after dark hour circle reads to one minute of time with diaphragmed mirror or eye-end dia- and the declination circle reads to 10 phragms. The original drawings were minutes of arc. The finder is a 4Xach- made at the eyepiece while using the romatic contraption which gives a field slow motion in R.A. to keep the planet of almost exactly five degrees which is in the center of the field. I used a circle quite convenient. The small telescope 30mm. (1 3/16") in diameter which was attached to the 8-inch is a 2'/s-inch ach- drawn with a compass on white paper. romatic refractor with powers of 48X, The general outline was sketched with a 72X, and 108X. This little telescope is pencil and then worked for detail by 'es- very handy, since it is easily removed ing various powers (120X mostly). Th and placed on an alt-azimuth tripod, penciled surface was rubbed with a piece thus affording a portable instrument. of cotton in order to give it a more The 2'/s-inch was my first telescope and even shading. The circle was then cut through the use of it I became acquaint- out and pasted on black construction

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 50 Amateur Astronomy May, 1938 paper for photography. By reducing IC,. f4:5 lens of slightly over six-inch the image in the photographic process, focal length mounted in a metal box I secured a fairly even and smooth ap- with plate holder (4" X 5"). This cam- pearance. I also found that photograph- era is to be attached to the tube of the ing the image slightly out of focus gave 8-inch and I am going to try my hand better results. The markings on one of at stellar photography by driving with the drawings were worked out by Tho- manual slow motion. I hope this little mas L. McDonald of Glasgow, Scotland. lens will prove suitable for comets and The central meridians of the various meteors. I hope to be able to secure drawings were figured by Hugh M. John- fairly good stellar images by the above son of Des Moines, Iowa. I am very method since the foial length of the 8- grateful to the above mentioned persons inch is approximately 10 times that of for their help. Should the reader desire the camera lens. I also intend to experi- to see the results obtained, I refer you ment with an unusual type of drive to The Sky, October 1937, Vol. 1, No. which may be suitable for driving the XII, page 25. A print of the drawing short focus lens. I should like to hear for June 10, 1937, was published in the from amateurs who are interested in July 1937 issue of The Texas Observers' drives. Bidletin. Should anyone be interested in I have tried my hand at several 6-inch a copy of some of the drawings, please mirrors and I have made a complete write me. mount for one. I find this type of work Photography with the 8-inch has been fascinating. limited to lunar photos due to the lack of a drive and suitable current for one. Smyer High School, Hockiey County. However, I am having a B. & L. Tessar Smyer, 'fexas. The Trig Micrometer By D. F. BROCCHI with this ment and removal of the cell carrying A contraption christened bar name has been devised to determine the the bar. It may be well to arrange from two stars of and dial for a low and a high power position of a star may be equipped known position. It can be used with any ocular, or one of the two mount, although the equatorial is most with permanent bar and dial, if it can be and ac- spared from other uses. While low pow- suitable for facility of operation faci- curacy of results, especially if clock ers have a larger field, high powers nor expensive litate the location of fainter stars. The driven. It is not difficult enlarging the to make, requiring only common hand field can be enlarged, by very likely available opening in the diaphragm, or this may be tools and material of doubt- in the junk pile. It is not necessary removed as a piece of apparatus that the three stars be seen in the same ful utility. The opening in the cap may reference also require enlargement for a full view field, but if A and B are the should stars and X the star to be located, each of the enlarged field. The pointer distances AB, AX and BX must be be on a hinged support to fold out of of the the way when not in use, and may be less than the diameter of the field. vernier for vry The instrument consists of a straight made in the form of plane of the ocular, close reading of the dial. bar fixed in the focal from two A a full circle dial attached to and con- To locate a star X stars and a pointer and B, turn the ocular to set the bar centric with the ocular, stars A-B, attached to the telescope and flush with sumessively in contact with The bar should A-X, and B-X, and make a note of the the edge of the dial. of be just wide enough to be seen plainly direction angle, or simply direction, The work- each setting indicated by the dial. For without artificial illumination. the final ing edge coincides with a diameter of the close adjustment of the bar, The other edge turning of the ocular is made with finger field or very nearly so. dial. The is marked with a few notches to indicate and thumb on the edge of the will of the triangle that it is not to be used. The dial hould notes give the angles back as practicable, ABX, and the position of X may be ob- be thin, set as far as- and of the largest size that will clear tained by solving for AX and BX, A dial of suming ABX a plane triangle, or it may the nose of the observer. 2/" the chart with a diam., 1/e" beyond the face of the cap is be plotted directly on nose. It is protractor. The distance AB is scaled about right for the average right graduated at intervals of 2 or 5 degrees on the chart or calculated from the (counter angle triangle ABN of Fig. 1, where and numbered sinistrorsely declination. If clockwise) and continuously all the way AN is the difference in dial should be a is the difference iii right ascension in around. The bar and the declination, removable, if the ocular is to be used degrees, and d the mean in which case a posi- of two stars A and B, we obtain the for other purposes, of arc tive one is more convenient for the place- angular measure BN in degrees PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor May 1938 Amateur Astronomy Page 51 N or its substitute with the working edge of the bar facing the interior of the triangle; set on the second side facing the exterior, and on the last side facing the interior. (4) Subtract the direction of AB from that of the second side, and the direction of this from that of the third side. If the subtrahend exceeds the minuend, add 360" to this before subtracting. The differences are interior angles. The third interior angle is the supplement of their sum, and is also by the formula equal to the direction of AB plus or BN = a cos d minus 180" minus the direction of the third side. Obviously 1800 is to be added, With the two sides AN and BN known, if the direction of AB is the lesser of the the hypothenuse AB can readily be calculated. two. With an equatorial, only one setting To be strictly correct, ABX being a on AB is required for all stars on the spherical triangle, the sum of the three same side of it, but with other mounts, angles is more than the sum of two if many stars are to be located, a new right angles, but the excess is too. slight setting on AB should be made from time to be considered for an instrument of this to time to reduce the error due to the type and triangles with sides limited in turning motion of the image. extent by the field of a telescope. To make this statement more definite, the When it is seen that the angle at X excess has been c.alculated for equilateral. would be too large or too small for the triangles having sfdns..of.i, 2 3 4 ¿nd 5 required degree of accuracy, one or two degrees with the following results: 00 0' siars already located are used in place 00 49FF 50 00 7F 1' QQ 4 15", of A or B or both, so the angle may be 00 11' 1", respectively. Let it be noted nearer to a right angle. furthermore that these are extreme vab To avoid confusion in deriving the ues, the equilateral having a greater angles from the notes, the work should excess than be done according to the following rules: (1) Turn the ocular from setting to set- same perimeter. ting always in the dextrorse (clockwise) It will hardly be necessary to mention direction. Incidentally this direction will that the letter X, denoting any star to prevent unscrewing the cap, if the ocular fits tightly in the tube. (2) Follow the be located, is replaced in practice by a, perimeter of the triangle around sinis- b, e, etc. for individual stars. trorsely (counter clockwise). For ex- 4331 Thackeray Place, ample, in Fig. 2 set successively on AB, Seattle, Wash. BX and AX. In Fig. 3 set successively on AB, AX and BX. (3) Set on AB

FLASH!

Milwaukee hereby invites every amateur within 1,000 miles-or beyond-to come to its open house week-end party June 18-19, There will be opportunities to visit with fellow TN's and stargazers and to inspect the new quarters of the Milwaukee society on the Phil- lip's farm site. Definite iñstrúctions on how to reach the observatory will be published later, The latch key will be out, Be sure and keep these dates open for us.

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 52 Amateur Astronomy May, 1938 Prepare for Palomar! LEO J. SCANLON While the 200-inch telescope will not permit a swarm of bees to alight in his be completed until 1940 (date set by trees? It seems to me that the Lowers, optomistic scientists), it is not too early our amateur friends in San Diego, could for most of us to lay our plans and rent out a ball park there for the use begin saving our money against the day of any of us who came by trailer, and when we will be permitted to see this we could have a convention to top off our modern marvel in all its glory on the visit to the coast probably ending up in heights of Palomar Mountain. It is here- Los Angeles and Hollywood, where it is by suggested that there be formed "Ttvo- hoped we can get a more satisfactory hundred Inch Clubs" in all the large view of some stars in that remote clus- towns throughout the United States par- ter. Incidentally, some of them are tele- ticularly those in the region east of the scope nuts, too, or did you know? Mississippi, the purpose being to encour- This idea is given for what it may age the amateur to salt away his stray be worth; it has infinite possibilities. dimes, nickles, and pennies for the next Just imagine a caravan starting from the two or three years so that when the east, picking up stray thumb-weary time is propitious, and final arrange- amateurs along the dusty road, stopping ments have been completed. we can be- overnight at Canyon Diablo, Flagstaff, gin the trek to California Tech and sea Tuscan, visiting the observatories and "Big Bertha" in action, Of course, the tourist sights along the route! Boy, that astroncmers and scientists in charge of would be something worth saving and the observatory on Palomar have not slaving for! Who's with me? The trip been consulted as to their views on this from the Atlantic region could not be proposed mass visit of amateur astrono- done in less than a month. We would mers, but it is the writer's belief that live on hot dogs and ice cream cones, they would just as soon have us come expect to stay at tourist cabins or camps, all at once, rather than in twos and a in the threes, and get the darn thing over with. and spend month hosnital re- cuperating upon our return . Isn't the As a matter of fact, there is little they prospect grand? could do to deter us from coming-who ever heard of anyone asking the Valley 'View Observatory, of an orchard whether or not he would Pittsburgh, Pa. Planetary Report No. 28 E. P. MARTZ, Jr., Di rector, Planetary Section JUPITER'S GREAT RED SPOT IN ing from 146°.5 on June 20, to 143°.2 1936; III: In Planetary Reports No's on Sept. 29, a shift of the order of mag- 14 to 16, (Amateu'r Astronomy, Octo- nitude reported by Wilson and Haas but ber and December, 1936), and in A.A., in the opposite direction! (Astronomische November, 1936, we recorded observa- Nachrichten, Nr. 6263, 261/23, Jan. 14, tions of the longitude of Jupiter's great 1937.) red spot (System II), by Messrs. Lati- With a total of 40 longitude observa- mer J. Wilson and Walter H. Haas, tions by the five different observers from and values obtained by the observers of March 16 to Sept. 29, 1936, the writer the British Astronomical Association, has undertaken a quantitative examina- communicated to the writer by the Rev. tion of the data in an attempt to dis- T. E. R. Phillips. The values by Wilson cover if the contention made by Wilson and Haas indicated a motion ranging and Haas of a shift in longitude is justi- from 142° (Wilson) in June to as much fied. The application of normal proba- as 151° (Haas) in September of 1936. bility law to such a small number of ob- The British observers, led by B. M. Peek servations by different observers is per- and Rev. Phillips, could not corroborate haps not justifiable, but the opportunity this gradual shift of position of the for such an application seemed tempting, marking. and the matter remained con- and the results obtained are of interest. troversial. In conversation during 1937, It was necessary to make the assump- Dr. E. C. Slipher of the Lowell Observa- tion that all the observers had about tory told me that he had measured his equal ability in making longitude deter- photographs of Jupiter in 1936, and had minations. For convenience the 40 ob- obtained a nearly constant longitude of servations were divided into nine groups about 143° throughout the opposition, with respect to time, as indicated in the thus corroborating the values obtained table at the end of this article. Eight by the British observers. Rather sur- of these groups covered consecutive in- prisingly, the well-known German ob- tervals of 20 days each, but as there was server, Herr Phillip Fauth, obtained an excess of 29 days between the first longitudes for the red spot in 1936 rang- and last observations, this time interval PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor May1938 Amateur Astronomy Page 53 was used for Group II, in which period from the above analysis of observations no observations were available, so the by all the observers. The shift indicated excess of time interval for that group by Haas was even greater, being as large will not affect the results. The arith- as 11°.O from June to September. Des- metical mean longitude for the red spot pite these residuals, as we have seen was taken from all the observations above, the combined observations of live available in each group, regardless of observers (even including those of Wil- who the observers were. Each group son and Haas) do not bear out a longi- mean was weighted by means of the irum- tude shift of greater than one-half to ber of observations composing that group. one-tenth that indicated by the two mt- The deviations of the individual weighted ter observers. Further, B. M. Peek, longitudes from the weighted mean for director of the Jupiter section of the the group were then taken. These in- B.A.A., has indicated that the probable dividual observational deviations were error of the usual method of longitude squared and plotted against the proba- determinations for Jupiter is of the order bility of each deviation, determined from of 10.2, and may occasionally reach 3'.O normal probability law and the respec- (Journal of the British Astronomical As- tive weights. A true normal probability sociation, February, 1937, p. 153, and curve was then superimposed on this The Obse'rvatory, Sept., 1936, p. 274). graph, and all the observations whose The longitude shift of 10.1 indicated by squared deviations from the mean fell the combined observations is thus clearly outside of the normal probability distri- within the scope of the probable error of bution (which allows only minor acci- determination; and the shift of 2°.3, dental errors arising from inherent in- indicated by Wilson, is also probably accuracy of the observational methods) not in excess of his probable error, since were rejected. Nine of the observations his determinations were often mean val- were thus considered unfit for use in ues from the longitudes of the ends of this determination. These rejected ob- the red spot, which he himself recorded servations were distributed thus: Wilson as being variable in length. In addi- 3, Haas 3, Phillips 2, Fauth 1-which tion, some of his longitude values were is about the distribution to be expected apparently determined from drawings, considering the fact that approximately and would thus have a higher probable the same relative numbers of observa- error than the transit observations of tions were contributed the British observers. The same con- observers. Final mean values of the siderations apply to Fauth's observed longitude for each time group were then residual. The high residual obtained by taken and are indicated in the table Maas is unexplainable by accidental er- alongside of the preliminary mean taken ror on the normal probability distribu- before the rejection of the badly dis- tion; and as the early values he obtained cordant observations. The validity of in June, 1936, agree in order of magni- the process was also checked by the ap- tude with those of the other observers, plication of the principle of least squares it is apparent that some error was intro- to the observational data. duced in the later, badly discordant, ob- The table indicates decreasing longi- servations. As one would expect obser- tude (i.e., speeding up of the motion of vational skill to increase with time and the spot), through groups I-V, and then experience, not to decrease, the error was increasing longitude (i.e., slowing down most probably in the time-piece used for of the spot) through groups VI-IX. The his later determinations. Further, his mean longitudes of all four groups from longitudes were all determined from March 16 to July 7 is 143°.6; and that drawings, and the probable error of these taken from July 8 to Sept. 29 is 144°.8, was apparently rather high-of the or- the residual being 1°.2. If we take, sim- der of 5°o of longitude. It may be ilarly, the mean longitudes from the argued that half of the observations used group means as uncorrected by the re- in the above analysis were affected by jection of the nine discordant observa- a (plus) probable error, and the other tions over the same time intervals as half by a (minus) error, thus neutraliz- above, we find a residual of 1°.l, thus ing the effect of the errors in the mean indicating that our rejection of discor- residuals, and validating the contention dant observations did not greatly influ- of at least a 1°.2 shift in longitude indi- ence the final result and was justifiable. cated by the final means. However, the Now, it would appear that this grouping relatively small number of observations of all the available observations does up- available (40), and the inequality of the hold the contention of Wilson and Haas probable errors of the five individual that the red spot shifted longitude in a observers do not appear to justify this plus direction in 1936. However, Wil- assumption. son's mean values, as published in Plane- In conclusion the combined tabulated tary Report No. 14, range from 143°.2 m observations indicate a small motion in June to 145°.5 in August, a shift of a plus direction in longitude for the red longitude of 2°.3, twice that indicated spot during the summer of 1936, but a

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 54 Amateur Astronomy May, 1938 motion whose magnitude is less than, or times given in this note indicated as: equal to, the mean probable error; hence, "G.C.T." (Greenwich Civil Time), start- in the opinion of the writer, cannot be ing at midnight. It is obvious that this considered as representing a real shift is an error, and that all the times noted in the position of the Jovian marking. should be by: "G.M.T." (Greenwich CORRECTION: In Amateur Astrono- Mean Time), which starts at Greenwich my, February, 1938, the writer present- Mean Noon. ed a "Note on the Predicted Transit of 726 N. Elmwod Ave., the Hypothetical Planet Vulcan". The Oak Park, Ill. MEAN LONGITUDES OF JUPITER'S GREAT RED SPOT March to September, 1936 (A) (B) (C) (D) (E) (F) T March 16 April 5 2 145°.5 145°.5 II April 6 May 5 0 (No observations) III May 6 May 26 3 143°.2 143.2 W May 27 June 16 4 142°.0 142°.O V June 17 July 7 8 143.4 143°.8 VI July 8 .Tuly 28 7 143°.8 144°.2 VII July 29 Aug. 18 6 144°.2 143°.9 VIII Aug. 19 Sept. 8 8 145°.2 144°.5 IX Sept. 9 Sept. 29 2 1460.6 146°.6 Explanation of Table Column: (A) Number of Group with respect to time. (B) Date of beginning of time interval for group. (C) Date of ending of time interval for group. (D) Weight; number of observations in group. " (E) Mean longitude of Great Red Spot for group. (uncorrected.) (F) Mean longitude cf G.R.S. after rejection of discordant observations from all groups.

Variable Star Section D. W. ROSEBRUGH, Director RIPPLES may teach us an hundredfold as much as we have already learned. Willows whiten, aspens quiver, Radio and wireless waves are now of Little breezes dusk and shiver, tremendous importance to mankind. Ap- On the stream that runs forever, parently no one anticipated their exis- By the Island in the river tence until Maxwell postulated it on Flowing down to Camelot.-Tenny.son theoretical grounds in his great sbedy "Electricity and Magnetism" made in Last month we talked about waves and 1873, Hertz showed their existence ex- the wave-like changes in the brightness- perimentally in 1888, and Marconi in es of periodic variable stars. These 1897 began to put wireless telegraphy stars were classified as (a) cluster type on a commercial basis. Possibly some stars which vary through approximately new astrophysical instrument not yet in- a magnitude, and complete their cycle vented may furnish mankind a tool with in less than a day, (b) cepheids which which to detect new types of star pheno- take several days or weeks from maxi- mena which are not now suspected. The mum to maximum, and (c) long period spectroscope, and perhaps to a lesser variables which take somé months or extent photography, did this for astro- even a year or more per cycle. nomy in the last century. The cluster type stars may 5ustly be Possibly we shall learn more about considered the "ripples' of this group- variable stars through the work of some ing, which depends to a considerable ex- brilliant mathematical astrophysicist, tent upon wavelength or length of period month who may draw unforeseen but sound con- from maximum to maximum. This clusions from existing data about these we will turn our attention to the facts that cluster type, or HR Lyrae type stars stars. as they are sometimes called, have Perhaps further facts on variable stars taught astronomers. It must not, how- secured with our existing means may ever, be considered that what they have permit more accurate conclusions to be already taught is all that can be learned drawn regarding the nature of these from them. Perhaps greater refinem._.ta stars. The more we learn about a sub- in our methods of study along the lines ject the more we find left to learn, and suggested in the next three paragraphs yet the faster we accumulate knowledge.

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor May 1938 Amateur Astronomy Page 55 It is this principle of learning which years or 15,000 parsecs. An extra mag- justifies the continued existence and vig- nitude fainter or 16.7 magnitude in ap- orous growth of the AAVSO since its parent brightness increases the distance founding in 1911. by the square root of 2.52 or to about Thus far astronomers, have learned 77,000 light years or about 23,500 from cluster type variables the distances parsecs. of star clusters, and as a result of this Thus far we are on firm and familiar knowledge they have learned, among ground. "But", you ask, "what part do other things, the approximate distance the cluster type variable stars play . in to the center of our galaxy. The meth- all this?" Simply this: it has been ori of determining the distance of a dus- found that if one can determine the ter type variable star is simple. Sup- length of the period of a cluster type pose that some night we drive to the star from maximum to maximum one top of a nearby hill and look down on our can estimate its absolute magnitude with own city or village. We see the street some degree of accuracy. This Lumino- light in front: of our house which we sity-Period Law for Cepheid variable know to be 100 watts in size, and to be stars, as given in Dingle's .4strophysics exactly a mile distant. We see a second published in 1927 may be tabulated as street light which appears to be the follows : (Note : It is believed that this same brightness. Assuming that all the table has been modified slightly since lights distribute their beams equally in 1927 perhaps about as shown in the last all directions as stars do, this may be column in brackets) another 100 watt bulb a mile away or Period in Days Absolute Mag. it may be a 400 watt bulb two miles 0.25 -0.3 (-0.3) away, or a 1000 watt bulb 3.16 miles 0.63 -0.3 (-0.3) away, or it may be a 50 watt bulb 0.7 1.59 -1.0 (-0.7) of a mile away. If we were told the 4.0 -1.8 (-1.2) brightness (wattage) of this second 10.0 -3.2 (-2.0) Street light we could at once determine 25.0 -4.6 (-3.3) its distance. Similarly we note a third 63.2 -6.0 (-4.4) street light which we estimate is one 159.0 -7.0 (-5.8) magnitude brighter, or 2.52 times as Leav- a This law was discovered by Miss bright as number one. This may be of Harvard College Observatory in watt bulb mile from us or a 1000 itt we her studies of the lesser Magellanic watt bulb two miles from us. If Cloud, and by Dr. Harlow Shapley, im- know the exact wattage of any of the the see the mediate past-president of AAVSO, street lights which we can from from the study of 11 typical Cepheids in hill top and can determine its apparent our own galactic system. These latter brightness as compared to the 100 watt eleven stars corresponded to the 100 watt bulb in front of our own house, we can street light, in the illustration given determine the distance to the street light is above. In other words their distances in question. lin terms of stars this were determined with some accuracy by expressed as follows: If we know the statistical methods, and since their ap- apparent magnitude of a star (Procyon parent brightnesses were known fro.m the 0.5) and its absolute magnitude (Procy- photographic plate, their absolute magni- on 2.9) we can determine its distance tudes could be determined. years or 3.1 parsecs). (Procyon 10 light And now for an illustration of how The exact relation is that a star of this method is applied in practice. This apparent magnitude 1.0 (brightness to is from the pen of the second vice-presi- eye) with an absolute magnitude of 1.0 dent of the AAVSO, Dr. Helen Sawyer (wattage of bulb) is 10 parsecs or 32.6 Hogg. In the February 1937 Journal of light years distant (distance to street the Royal Astronomical Society of Can- light). This relation is capable of in- ada, Mrs. Hogg reports the results of definite extension by the use of the n- her study on the globular cluster N. G. verse square law as follows: If a star C. 6402 (M14 in Ophiuchus). When the of absolute magnitude is -0.3, it ap- writer last saw Mrs. Hogg at the David pears as -0.3 magnitude to the eye if it Dunlap observatory in 1936, she kindly is 32.6 light years away. If it appears showed him some of the 48 photographs 2 magnitudes fainter or 1.7 magnitude of this cluster which she had secured at it is 2.52 times as far away, because a the Newtonian focus of the 74 inch re- drop in brightness of two magnitudes flector. In these photos the cluster was corresponds to a decrease in light re- perhaps 11/e inches in diameter and the ceived to the reciprocal of 2.52 squared. images of the individual stars had to be If the star appears as 3.7 magmtude, it examined with a strong magnifying is 2.52 squared times as far away; if it glass. apuears as 15.7 magnitude it is power times 32.6 Sixty-one cluster type variable stars 2.2 to the eighth were located in N. G. C. 6402. The exact light years away, or approximately 1500 times 32.6 light years or 48,900 light (continued on page 57) PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 56 Amateur Astronomy May, 1938 Meteor Section J. WESLEY SIMPSON, Director Unfortunately, there is usually very try of our group. In fact, the totals little to report for the first three months for this three month period exceeds the of the year, hence the smallness of this total for any six month period (January report. It is hoped and expected that through June) in our history. Reports with the advent of Spring, warmer from all of our observers are not in as weather, and clearer skies, the activity yet and when they are recèived, our in this field will increase many fold, totals should be close to 2,000 meteors. Regional Report No, 3801 for Missouri Before the month of April is over, the and Southern Illinois 40,000 mark will have been reached since (January through March 1938) WO started in 1932. J. WESLEY SIMPSON, Regional Director The explanation for the M-SIO's fine The following is a summary of the showing so far this year lies in the fact activity in the Missouri-Southern 1111- that we had what was probably the lar- nois region during the first three months gest Quadrantid meteor shower on record, this year. and that some six or eight of our work- In checking the totals for this period, ers are observing with remarkable con- your writer finds that this is the Iarg- sistency. est report for such a period in the his- The report is herewith given: TABLE No. 1 - INDIVIDUAL TOTALS Number of Minutes Meteors Observers Nights Observed Recorded Donald D. Zahner (1) 13 1,2:40 225 Harry Bruggemann (2) 4 400 83 Edwin E. Fritan (2) 4 330 204 Joe H. Senne Jr. (2) 3 240 73 James F. Brady (1) 2 180 53 M. Weston Tate (3) 1 195 250 Mary Ellison (1) 1 120 53 J. Wesley Simpson (1) 26 3,360 820*** Totals: 8 Observers 34 6,065 1,761 ***Includes 8 telescopic meteors. (1) Observers live in Webster Groves, Mo. (2) Observers live in St. Louis, Mo. (3) Observer lives in Alton, nl. TABLE No. 2 - MONTHLY TOTALS Observed A.M.S. Month Observers Nights Minutes Meteors Rate Rate K-O January 8 10 2,265 1,265 33.6 8.0 plus 25.6 February 4 9 1,380 203 8.76 6.0 plus 2.76 March 4 15 2,420 293 7.26 7.0 plus 0.26 Totals: 8 34 6,065 1,761 The number of nights is not the total of all observers but is the number of different nights on which observations were made. The K-O is the known or A.M.S. rate for the month minus the observed rate.

Dr. C. P. Olivier Visits St. Louis, Mo. of the work being done elsewhere in the For many years your writer has cor- world. It is with regret that this space responded with Dr. Olivier, of meteor is too short for printing some of the fame, but never had the pleasure of discussions. meeting this distinguished astronomer until Wednesday, April 13, 1938. When Milwaukee-Webster Groves Radio one has the pleasure and privilege of Hook-Up working under such a man, it is of course On Thursday, April 14, at 10:15 P.M., natural to look forward to the time when L. E. Armfield, representing the Milwau- you can sit down and discuss your prob- kee group and region, and J. Wesley lems face to face. Thus it was quite Simpson, representing the Missouri- a gala occasion for St. Louis when he Southern Illinois Section, inaugurated a visited us, though he was here on busi- two way radio hook-up between the two ness and had little free time, St. Louis cities. is a rather poor place in which to find Mr. Armfield talked over amateur ra- astronomical celebrities. dio station W9MKC, in Milwaukee, It was exceedingly interesting to hear owned by M. A. Ziehins of that city. from the lips of this scientist some of Mr. Simpson talked over amateur radio the latest developments and theories, and station W9UAE, in Webster Groves, Mo.,

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owned by J. R. Stafford of that city. Z UMa is now (979) about 73; this A discussion of many topics was made star and possible by Messrs. Ziehms and Staf- R CrB will be favorably placed ford. The connections were easily and for beginners for some months. 210868 quickly made. The QSO was considered T Ceph is rising, having reached 106 by all as being most successful. on 950. When last seen, 233815 R Aqr The next conference is scheduled for was declining, having reached 91 on 931. Monday, May 9, at 10:00 P.M., when it is hoped that Ed Martz o'f planetary General Notes fame and Ed Friten, asteroid section The following comments from George leader for the AAAA, can be introduced Herbig, 2016 Ewing St., Los Angeles, over the air waves. Tune in on the 75 are of more than usual interest: the meter band on May 9 at 10:00 P.M. 18-inch Schmidt camera now on Mt. Pa- lomar has been so successful that a 48- inch camera has been decided upon. The following data show a comparison of the Variable Star Section existing 18-inch camera and the proposed (continued from page 55) 48-inch. 18-inch 48-inch periods of nine of these were determined Focal length 36" 120" and found to lie in the range 0.55 to 0.50 of a day. Referring to the above table Mounting Fork Fork it is apparent that their absolute magni- Guiding telescope 8" refl. 10" refi. tude is -0.3. The mean magnitude of Photogr. field 10 degn. 61/a degr. the cluster type variable stars in N. G. C. Mirror diameter 26 inch. 72 inch. 6402 is 16.85 as shown on the photographic plate. Referring to the discus- Mr. Herbig also says that the dome sion in the paragraph preceding the for th 200-inch is completed and the first parts of the meuntingare expected table, a star of -0.3 absolute magnitude to arrive which appears as 16.7 magnitude on the this summer. ThëThigpirror is approximately a year ahead of hed- photographic plate is 77,000 light years ule. or about 23,500 parsecs distant. The un- adjusted observations therefore indicate . The Los Angeles amateurs are consid- that N.G.C. 6402 is 23,500 parsecs distant. eningi the possibility of moving their However, the paper discusses the proba- clubhouse into the hills at the edge of bility that N.G.C. 6402 is dimmed about the city. They hope that their 15-inch 1.26 magnitudes by absorption of light reflector will show them 16th magnitude in space in that direction. f the magni- stars in the clear atmosphere of the subS- tudes of the cluster type variable stars urbs. as shown on the photographic plate would On March 25 the members of the have been about 1.26 magnitudes bright- Poughkeepsie Astronomical Club who er, i.e. about 15.6 magnitude instead of were observing variable stars and me- 16.85, and if it had not been for inter- teors at the Vassar College observatory, stellar absorption of light, the distance through the courtesy of Dr. Maud W. of the cluster type variable stars would Makemson, Director, saw a beautiful but be less than 15,000 parsecs, probably transitory aurora. At about 8:30 E.S.T. about 14,000 parsecs. After some dis- Polaris was surrounded by a beautiful cussion Dr. Hogg tentatively places the rosy glow, the color of a dark red peony, distance of N. G. C. 6402 at 12,000 par- and beneath it white curtains of light secs. shimmered. In about five minutes this display diminished to a few scattered Notes on Observations streamers of white light. About 3:45 Ferdinand Hartmann reports that Mi- a beam of light spread across the sky from the east southeastern horizon to ra (o Ceti) reached 8.3 on 946. It is the west north-western horizon, passing now lost in the sunset. R Aur 050953 slightly south of the zenith. This beam jumped rapidly from 114 on 929 was about three degrees in width to 86 on 951. It is now bright throughout its entire length of nearly enough for easy observation with the 180 degrees and it remained practically red color filters and red charts. T Ono- motionless for perhaps 20 minutes. Beta nis 053005a was practically constant at Leonis was slightly obscured by the bril- about 10 mag. all February, but by 979 liance. About 9:10 this beam largely it had dropued to 10.9. SU Tau 054319 disappeared but the center part broke appears to have been fairly constant at toto striations which formed an active about 9.5 during February and March corona about 15 degrees south of the and S Aun 052034 has been about 101 zenith. during the same period. Mr. Hartmann '74 So. Randolph Ave..

caught Z Cam at 113 on 925. 115158 Poughkeepefe, . . PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 58 Amateur Astronomy May, 1938

Calendar of Events The official monthly publication of th GEORGE DIEDRICH American Amateur Astronomical Association (All Time C. S. T.) Publication Headquarters PHENOMENA OF JUPITER'S 1312 E. Curtis Place. Milwaukee. Wis. SATELLITES Affiliated Societies Astronomical Society of Rutherford. N. J. (In C.S.T.) Amateur Astronomers Association of Pittsburgh. MAY, 1938 Pennsylvania. Astronomers Guild of Jamestown, New York. May Time Sat. Phenom. Chicago Amateur Astronomical Association, Chi- cago. Ill. 2 Mon. 2:57 A.M. II E D Eastbay Astronomical Association, Oakland, Calif. 4 Wed. 1:55 Ä.M. I T e The Long Island Astronomical Society, Wantagh. 4 Wed. 3:04 A.M. II T e N. Y. 7 Sat. 2:33 A.M. Louisville Astronomical Society, Louisville, Ky. IV E D Madison Astronomical Society, Madison, Wis. 10 Tue. 3:00 A.M. I E D Metropolitan Astronomical Society. New York. 11 Wed. 1:34 A.M. I T i New York. 11 Wed. 2:32 A.M. I S e Milwaukee Astronomical Society, Milwaukee, Wie. New Jersey Astrophysical Society, Woodbridge, 11 Wed. 2:53 A.M. II T i N. J. 11 Wed. 3:02 A.M. II S e Norwalk Astronomical Society. Norwalk. Conn. 16 Mon. 12:58 A.M. IV T i Optical Division of the AAA, New York, N. Y. 18 Wed. 2:09 A.M. I S j Editorial Staff 18 Wed. 2:46 A.M. II S i Miss Elizabeth Wight, Editor 24 The. 1:30 A.M. IV E R Mrs. A. K. Fisher T. R. Hedengren 26 Thu. 1:17 AM. I E D E. A. Halbach Earl Needhasn 27 Fri. 12:47 A.M. I S e Advisory Editors 27 Fri. 2:07 A.M. I T e ]'rof. Leon Campbell - Variable Stars. 27 Fri. 3:12 A.M. III E D Prof. Charles P. Olivier Meteors. Prof. George Van Biesbroeck- Asteroids, comets, 29 Sun. 12:19 A.M. II T e and double stars. - 31 Tue. A.M. - 2:04 iIí---Te Ten cents per copy. $1.00 per year.

JUNE, 1938 - - Membership in AAAA. $1.00 per year including subscription. 2 Thu. 3:11 AM. I E D Send all communications to the above address 3 Fri. 12:24 A,M. I S i 3 Fri. 1:43 A.M. I T i 3 Fri. 2:29 A.M. II E D Total eclipse begins-Sat, at 2:18 3 Fri. 2:40 A.M. I S e A. M. 5 Sun. 12:02 A.M. II T i Middle of eclipse-Sat, at 2:44 A.M. 5 Sun. 12:11 A.M. II S e Total eclipse ends-Sat, at 3:09 5 Sun. 2:53 A.M. II T e A. M. 7 Tue. 12:39 A.M. III S e Moon leaves umbra-Sat. at 4:31 7 Tue. 2:26 A.M. III T i A. M. 10 Fri. 2:18 A.M. I S i Moon leaves penumbra-Sat. at 10 Fri. 3:06 AM. IV O D 5:43 A.M. 10 Fri. 11:33 P.M. I E D Magnitude of the eclipse 1.102 11 Sat. 11:56 P.M. H S i (Moon's diameter = 1.0) 12 Sun. 12:18 AM. I T e 19. Thu.-Greatest elongation west of 12 Sun. 2:34 A.M. II T i Mercury, 25° 37'. 12 Sun. 2:48 A.M. II S e 22. Sun.-Last quarter at 6:36 A.M. 14 Tue. 1:03 A.M. III S i Quadrature of Jupiter and the sun. (Satellites eclipsed on west 29. Sun.-New moon at 8:00 A. M. Tö side of the planet) tal eclipse of the sun-invisible in Explanation of symbols: North America. E-Eclipse T-Transit 30. Mon.-Conjunction of Mars and the S-Shadow O-Occultation moon at 11:54 A. M. Mars 3° 20' D-Disappearance north. i-ingress e-egreSs 31. Tue.-Venus in conjunction with the moon at 9:52 A.M. Venus 5s 6' MAY, 1938 north. 6. Fri.-First quarter at 3:24 P. M. JUNE, 1938 7. Sat.-Venus in conjunction with 00 4. Sat.-First quarter at 10:32 P. M. Mars at 6:00 P. M. Venus only 12. Sun.-Full moon at 5:47 P.M. 2' north. (For comparison-com- 15. Wed.-Venus at greatest heliocen- ponents of the double star Epsilon tric latitude north. Its position is Lyrae are about 4' apart.) R.A. D 52m, Dec. 22° 50' north. 13-14 Fri.-Sat.-Total Eclipse: Moon enters penumbra-Fri. at (Data from the Handbook of The Roy- 11:44 P.M. al Astronomical Socklety of Canada) Moon enters umbra-Sat. at 12:57 3333 w. National kvenue, A. M. Milwaukee, Wis.

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor May 1938 Amateur Astronomy Page 59 that depth has oeen reached. Then there Chicago Amateur was anoner group centered arouna a Astronomical Association errain map oi JNew york otate plotted snto sections showing eevaìons etc. inc MAX M. FEINSILBER. Secretary entire scene looked iike the subterranean fleaciquarters of a military expedition At the April 3 meeting of the association John Sharp gave a talk on astro- ready to telegraph orders to drop some nomical phenomena to be observed dur- eggs on this or tnat section N ot at ali. ing the mmainder of the year. His talk Lue boys were trying to locate a site showed a great amount of preparational icr the observatory. Last week eno some effort and was issterestingy given. A of them set out to look over likely spots short discussion foilowed. and get prices on mounta.n tops At four o'clock the group attended the With all this activity I began to won- regular Sunday lecture in the planeta- der whether I should have joined a kin- rium. This was in keeping with our ne dergarten astronomical association. My poìicy to attend at least one lecture a investigation showed that we have mcm- year given by the planetarium staff. oers wno are trained and qualified m- Now a look into the future. Our ten- cirinists, pattern and casting makers, tative plans are a visit to the Dearborn authorities on celestial photography, ci- Observatory at Evanston, Ill., a trip vil engineers, surveyors, architects, to Milwaukee to view their new observa- builders etc. While coming out of my tory, and a visit to Joseph Boehm's Lake trance a member walked in with some Geneva home at his invitation. With books under his arm, and one of them these outings on the program, we look had to do with cosmic rays! I came to forward to a successful and certainly an the conclusion that we had talent that enjoyable summer program. could handle far bigger jobs than our We wish to welcome into our fold a 21-inch. You can take it from me that new member, H. M. Robinson, Chicago, our observatory and our contributions Ill., who joined us at our last meeting. to the science will be news! Our meetings at Mr. Callum's home are The sides of the 21-inch mirror in our continuing with great success. We have shops are now being runded by an in- this month added another meeting to our genious invention of one of our members. list. We wish to thank J. A. Wingard, There. are really 32 sides to this pyrex Oak Park, Ill., for the use of his home disk, and the machine-a Rube Goldburg and yard for this purpose. contraption !-is doing a past criticism 6602 S. Francisco Ave., Chicago, Ill. job. On April 5 we accepted an invitation from the Rev. Joseph Lynch of Fordham University to visit the seismograph lab- Optical Division of AAA oratories and see particularly the Benioff HAYDEN PLANETAEWM Nuw YORK CITY seismograph which magnifies earth tre- Correspondent mors 100,000 times and makes photogra- R. WALLACE, phic records of them! Sela.h! After sending our repo.rt for March hayden Planetarium, Amateur Astronomy, your correspondent New York City. was about to wire his Mexican bull ranch to unleash Rufus, for frankly he wondered what specifically to report on, In this frame of mind he sauntered into Norwalk Astronomical the workshops one cold evening and was flabbergasted 'at the sight. For an in- Society stant he thought he had stumbled into MARY C. HAMILTON, Secretary the workshops of the 200-inch. Here The regular April meeting was post- and there were tables with improvised poned until the 7th when the college desk lamps and men working on or pour- students could attend. ing over large sheets of paper with slide rules and intricate mechanical instru- Again the members brought clippings ments. Others were referring to stock which suggested subjects for discussion. gear catalogs. Others were up to their The subject for the next meeting, ears in calculus. Others again were May 26, is meteors and we are planning grinding or polishing their mirrors. to assemble outdoors and perhaps see a Through the haze of smoke from Lady few. We hope for a clear evening. Nicotine it all looked spooky. It wasn't More interest in astronomy has been long before I ascertained the why and shown by the people of this town since wherefore. They were all engaged in last November, when the subject chosen planning the mount and putting finishing for children's book week at the public touches on the observatory for the 21- library was "The Stars." inch mirror which has been wheeled 4 ljnion Park. downstairs for further treatment now Norwalk. Cosin. PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 60 Amateur Astronomy May, 1938 Planets had families in those days, Tri State News Notes too. Neptune, for exampie, was sup- AMATEUR ASTRONOMERS' AssoCIATIoN posed to have six. (But If Neptune OF PITTSBURGH UOUL1) have six comets, why then, on CHESTER B. ROE, Correspondent the same basis of heavenly mechanics, 60 members of the Pittsburgh Nearly ,J upiter would have to have three mii- group attended the April meeting on tse lion!) eighth at the downtown Y.M.C.A. A The contraction theory of the sun's part of our summer schedule was dis- energy was likewise "in," with the sun cussed, and tentative plans were made supposedly contracting 250 feet a day. for our annual visit to Allegheny Ob- The earth was assumed to be 20 miliion aervatory. years old. (Atomic disintegration in Dr. Pendray of interplanetary rocket re- the sun and an earth age of the order fame was in Pittsburgh to lecture of 2,600 million years are the accepted garding the progress of rocket research. theories of today.) According to Dr. Pendray, the future Oh, yes, J upiter was a semi-sun, a of interplanetary communication by tresnenctously hot, semi-molten affair. rocket is far from being an actuality. "The farther outward in space we go," All he hopes to attain within the next said Mr. Cornell, "the worse it gets.' generation is mail service between Eu- Thus, space was populated with cold, rope and America. dark invisible stars. The obscuring Norbert Schell of Beaver Falls, re- matter in sagittarius was a corridor ported that work on his 10-inch casse- get a glimpse of space grain has reached the machine-work down which to form beyond. Novae were two stars colliding. stae. Mr. Schell also hopes to ("The collission theory seems the most a branch of our organization at Beaver amateurs absurd of all.") Falls as several interested Yet the "fiercest theory" Mr. Cornell live in his district. said, involved the causes of variable stars Next door to our meeting room a but, in magnificent group of children rehearsed for an -not pulsation our speaker's talk Fourth of July fashion, the collision of Easter program, so two meteor streams. Nebulae were was punctuated with "strains" of music. nebular hypothesis was However, Wm. P. Wieman, an electrical "fire mibt." The engineer and a member of our group, considered true. us many Theories, however, are often discarded succeeded in bringing to inter- will be the "ain't esting f.acts regarding the effects of like old shoes. What forces on sos" of the future? Mr. Cornell voted electric energy and magnetic as his "don't believes:" atoms. for the following April 1, V. E. Mayer of The expanding universe On Friday, The density of white dwarfs Indianapolis, md., arrived in town with lunar craters two friends to discuss with J. W. Fecker The meteoric origin of a correcting lens for the Super-novae in distant galaxies the contract for of some 36-inch reflector being built by the In- The low density stars dianapolis group for Dr. Goethe Link of The curvature of space session with Mr. If Milwaukee methbers seem to have that city. After the here is Fecker, Mr. Mayer was entertained in suspiciously puffed out chests, cellars, basements and other the reason: After years of construction and by the inactivity, the Milwaukee society now miscellaneous workshops of our members. the Bad weather halted most of the ob- has its own observatory, located at few variable Phillips farm. A steel dome houses the serving programs, yet a two observations were sent in. 13-inch. And there are two sixes, Valley View Observatory, fours, two tens and an eight. The labor N. S. Pittsburgh, Pa. was willingly donated-virtually thou- sands of dollars worth-plus much of the News Notes material. Now, with considerable excite- Milwaukee änd much stirring around, the ob- 1w. N. FISHER, Correspondent ment what ain't so-a review serving program has gone into effect "Astronom M. Prinslow, chairman of the of some o'f the stuff taught 35 years under C. ago and how it looks now, with some observatory committee. teach Every Monday night will be an open thoughts on how the stuff the profs nights now may look a few years hence." house night and on succeeding topic before him, various members will be engaged in de- With that lively work. Each Herbert W. Cornell gave the Milwaukee tailed, careful observing f ac- observer will have his own personal work society a well-filled, entertainingly the only tual hour on April 7. report to turn in with illness the cap- excuse acceptable. An automobile pick- At the turn of the century for those ture theory of comets was "in." Comets, up system has been started from mysterious who lack transportation to the "ob." so it was thought, came Wis. realms of space. (Today we say they Milwaukee, are members of the solar system). 817 N. 28th Street, PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor 1MATEU! &SftIi

BE VOTED TO

THE AMATfUR OBSERVER

JUNE-JULY, 1938

PU$LI&HO Il

AMERICAN AMATEUR ASTRONOMICAL AssOCIATION

VOL. 4 NO. 6

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor AMATEUR ASTRONOMY Published Monthly by the American Amateur Astronomical Association

The upper photograph, taken last winter, shows a general view of the observatory which houses a 13-inch reflector. The shelter at left houses Mr. A. C. Tabbot's 8-inch reflector. The lower left-hand view shows the 8-inch 'scope in use and the shelter rolled toward the north. The 13-inch telescope is shown on its mounting inside the dome in the lower right-hand picture. PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 62 Amateur Astronomy June - July, 1938 The Milwaukee Astronomical Society Observatory EDWARD A. RALBACE, President did the founder membere of the a 141/2-foot dome. Twelve small con- LLttle laid to support the Milwaukee Astronomical - Society realize crete piers were the importance of their plana for a building and dome. The frame and "caatle in the air" when in 1933 they sheathing of used lumber were covered decided it was time to build an observa- with new siding. The top of the side tory and began searching for a suitaible walls, three feet above the observing location. Without funds to purchase floor, supported by circular laminated property, the society was surprised by ring, 14 feet inside diameter, constructed the grant of an acre of land from one of a double layer of 2-inch planks. of its members, Mr. M. J. W. Phillips, Eight 5-inch inverted truck casters were with the stipulation th'at construction bolted to the ring to' support the dome. begin within five years. Since this site The skeleton of the dome was con- was in a favorable location, far enough structed of structural steel and covered from the city lights (15 miles southwest with 24-gage black sheet iron. A base of Milwaukee),. and on high land, it was ring of 4-inch channel iron, roiled with immediately accepted. the flanges outward, provided both a So enthusiastic did the observatory smooth track and a rigid base to which committee become that the property was the vertical ribs were welded. The ring immediately surveyed in spite of near was rolled in two sections, put in place zero weather. Frank Dieter, now of and welded together. The dome was Annapolis, Md., prepared a plan for a completely fabricated in its final position. proposed observatory according to the To keep the dome centered, a bracket suggestions of the committee, but as no with a 2-inch rolled mounted on top was immediate funds were available, the pro- fastened adjacent to each large casterS ject was shelved. Since the upper end o'f this bracket with For several years observational work roller extends into the open channel, the 'was carried on in the back yard of the dome is preven.ted from being lifted by home of our secretary, Luverne Armfield, high velocity winds. The 25 vertical in West Allis. Mr. Armfield had to ribs of 114-inch angles were welded to move inthe fall of 1936 and the observ- the base ring and to the 2-inch angles ing members were left without a suitable forming the slit which is three feet wide. place to congregate and observe. The one piece shutter lides off to one At a meeting held in Jun-', 1937, it was side on angle iron rails. The arc weld- decided that the construction of an obser- ing was done by the Nordberg Mfg. Co, vatory should be started according to the and the portable arc welder wa.s furnish- original plans. Before the meeting end- ed through the courtesy of the Harniseh- ed, $40.00 in cash was placed on the feger Corp. Although the dome is to be table by those present and promises were motor-driven through a rubber-tire drive made for more money to meet the first wheel, at present it is being turned by construction expenses.. Mr. Phillips fur- hand. All the metal work was painted ther offered to provide all materials and with two coats of red-lead paint and the tools for building the pier. exterior was finished in aluminum. A Construction was begun early in July lightning arrester with elaborate ground- with the digging of a hole six feet deep ing system was attached to the dome for to receive the form for the pier. The protection. portion under ground was made three The observing floor is reached by a feet square and extended 12 feet above stairway along the north wall. A trap ground, tapering to a cross section of door covers the stair opening for safety 12 by 18 inches at the top. The great while observing. The lower p.art of the height was needed to piace the telescope interior, at present unfinished, is used in the second story of the observatory mostly for storage of smaller t&escopea to conform to the original plan. All and other equipment. the building labor was furnished by the Early in May, exactly 10 months after senior and junior members of the society. construction started, Mr. Armfield's 13- Imagine the task of hoisting half the inch reflector was mounted on the pier, concrete for the 8-ton pier to the ton the mirror for which was loaned to Mr. of the form, 12 feet above the ground, Arnifield by the AAVSO. During the delivering the past winter, when work outdoors was with a small bucket! In moi'nting 10 cubic yards of crushed stone and not possible, the tube and the concrete. the Kohlei' Gray- for this telescope were completely re- sand for the con struc- el Co. donated half in exchange fr a built. 'The first step was the glimpse of th.e heaven.s when the tele- tion of a new mirror cell to rep'ace an scope was mounted. improvised holder of wood. The new cell Pianis called for a frame building 16 is made of a heavy rolled ring to which feet square and 13 feet high, supporting three mounting ears are attached. Six PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor June - July, 1938 Amateur Astronomy Page 63 support pads are placed in pairs to sup- unsound and broke off at the ground line port the mirror. causing our secretary, Mr. Annfieìd, to Since the origina1 mounting had no be precipitated at our feet. In coming drive, much work was necessary to adapt down with the pole, he spiked his left materials at hand. The drive consists leg with his climbing irons and is now of a Bodine 1/15 hp., 1800 rpm synchron- moving about on crutches. We wish him cM_ls motor, with the following gear train: a speedy recovery. 1:50 (worm), 1:1 (differential), 12:66 The observatory, as it stands today, is (spur), 1:50 (worm),and 1:188 (wcrm). the first unit of a proposed larger and The 188-tooth worm gear drives the po- more complete building. A second unit lar axis through a friction plate between of about the same 'size, to be constructed the upper bearing and the tube saddle. when funds permit, will be about 50 feet Slow motion in right ascension for directly west of the present building, the guiding purposes is obtained by a small two units to be connected by a one-story reversible motor which turns the differ- office, or meeting place, which can be ential housing through a 1:98 worm re- heated. Directly north of the center duction. A second small motor gives point between the first two domes, there slow motion in declination through prop- Is to be a larger unit to house possibly er gear reductions. The latter drive is a 20 or 30-inch reflector. Only the fu- engaged or disengaged by a solenoid ture -will tell whether or not the entire operated brake. plan will materialize. Since the 13-inch telescope is to be In addition to the present observatory used primarily for variable star work and telescope, there is an 8-inch F:15 in which rapid location of stars is im- reflector housed nearby in a rollaway portant, a R.A. cir&e was added in ad- shelter. This telescope, without a drive, dition to the conventional hour circle. belongs to Mr. A. C. Tabbatt and is in- A small synchronous clock motor was tended primarily for planetary observa- mounted on an 8-inch graduated disk for tions. A second, but smaller pier, is this baicelite R.A. circle which is free ready for the mounting of a 10 or 12- to turn on the polar axis. The 1-rpm inch reflector. shaft of the clock motor drives against The observatory program was begun the polar axis through the following gear with the prime purpose of utilizing the reductions: 10:40 (spur), 15:15 (bevel), equipment to the best advantage for ob- 1: 359 (worm to spur). A 32-tooth servational work. Hence, the 13-inch idler is necessary between the worm and telescope is to be- used only on variable the 359-tooth gear for the latter is an than 12m. Smaller tele- 48 stars fainter internal gear constructed f pitch scopes will be available to observe b"ight- brass rack mounted in the inner circum- er variables. Those participating in the ference of an 8-inch wheel. The circle observing program have been assigned index is fixed and adjustment is pro'v-ded certain nights of the week on which they by rotating the large gear and circle are responsible for the eouipment. assembly on the polar axis. The circle is set for the evening frcm the knowr Since meteor observation is to be part bright star near the eq'eator. of our observing program, we shall con- 1l.A. of a centrate our efforts on duplicate i-eio'ht The telescope can be correspondingly radio set to any desired R.A. without further work. A new 250-watt phone or without a sidereal clock. transmitter is ready to be irstalled at computations the observatory for coordinating d'upli A 12-gage sheet iron cover ene1 oses the The moflen cate meteor height observaicns. entire mechanism. The slow antenna, 240 feet long, is to be supported drives in R.A. and Deci. are operated by two 80-foot poles. A smaller portable frosn the observer's position through a the past 6-volt transmitter has been in ur in push button control box actuating again hi' needed. box also has and will be available A.C. relays. The control eve- a pair of push buttons for operating the Without mentioning the winter proposed drive on the dome. An illu- nings of 1937-8 when the intricate mount- minated chart holder is located near the ing of the 13-inch was reconstructed in and the basement of the home cf one of the eyepiece for the variable star charts of the two finders of 6inch focal length are mmbers, the actual construction telescope, one near each observatory itself took place during the mounted on the cf 1938. end of the tube. summer of 1937, and the snring aceeseries On an average of eight society members Since the telescope and Milwaukee could not be operated conveniently with- motored the 15 miles from power line each week-end, and oftener, during these out electricity, .a 1,500-foot put into was constructed from the Phililes farm two seasons, rain or shine, and The only the building their time, technical train- buildings to the observatory. of accident of any consequence occurred ing. plans, foresight and the sweat construction of this line. One their brow to make it a means of fur- during the on page 76) of the poles placed in the ground proved (continued

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 64 Amateur Astronomy June - July, 1938 Ionization of the Earth's Atmosphere MAUDE S. WIEGEL. Solar Director Taken from an article by I. V. l3erkner. Dent. of Terrestrial Magnetism, Carnegie Institute of Washington (ontinued from the April 1928 Issue) During the eclipse of Aug. 1932 it was regions during daylight is the uptra- noted by astronomers that a sudden violet light of the sun. Apparently the change took place in ionization in the ionization of the upper region is caused lower region of the earth's atmosphere, by a bombardment of the outer atmos- while only a slight decrease occurred in phere by particles emanating from the bhe ispper or F2 region. This held true sun. during the eclipse of June, 1936, in Rue- That two regions exist which both owe sia, yet during the eclipse of Feb. 193 their ionization to the same source (ul- observers noted a decided change of tra-violet light) presents another prob- ionization in the upper layer. Why do 1cm. A possible solution to this may be we have such conflicting data ? Methods the composition of the atmosphere itsell of abser'viation being accurate, the answer at these great heights. Physicists have will in all probability be found when shown that if we conceive the outer at- more eclipse data may be had from al] mosphere to be undisturbed, the lighter piarts of the world lying in the path gases will rise to highei levels than the of the solar eclipse. heavier gases. Winds keep the gases which mixed close to the earth so that the pro- Upon investigating the dates on and nitrogen is al- these observations were made it was portion of oxygen an ways the same. At greater heights, found that the F2 region exhibited lighter nitrogen should eclipse-effect only when it was merged however, the region, no effect float to higher levels than the heavier with the lower or Pj A of light entering the being observed to any extent when these oxygen. ray It would outer atmosphere will have passed a cer- regions were widely separated. of nitrogen atoms, after seem then that the force which is ioniz- tain number undergo penetrating through a certain amount of ing the upper region does not ray must pene- any change at the time of solar eclipse. atmosphere. The snrne remembered, however, that trate much more deeply into the atmos- It must be phere to pass the same number of oxy- this line of reasoning is based upon only gen most affective a few eclipse observations in one hemis- atoms. Oxygen is phere and that any conclusions must be in absorbing certain light-frequencies fur- while nitrogen is most active in ab- open to question until checked by light which ionizes ther eclipse observations. If an ioniz- sorbing others. The at the nitrogen will be 'absorbed at a high- ing agent from the sun is not eclipsed ionizes the the time of a solar eclipse, it can not be er level than the light which traveling with the velocity of light. This oxygen. suggests that the ionization of this up- There would be two distinct levels of per region may be due to particles which ionization, because of the absorption of are shot off from the sun and which a different ban.d of light by a different upon colliding with the molecules of the gas. The difficulty with such an ex- earth's outer atmosphere, knock off e1ec- planation is that as yet we can not be trons, thus creating the ionization which sure whether such a partial separation is observed. It would seem then that of gases by diffusion actually occurs in there is a bombardment of the outer the upper atmosphere and whether the atmosphere of the earth by particles atomic states which have been assumed frein the sun. Before accepting such in this example are actually correct. hypothesis as a fact, much data must be It is impossille to observe the high- had. The new automatic equipment will frequency radiation from the sun be- facilitate a continuity of data on the cause of its obsorption in the upper at- subject. mosphere. Some o'f the characteristics There are three main regions of ioni- of this radiation can be determined, zation at heights of about 65, 130 and however, from its reaction on the outer 180 miles respectively. Of these, two atmosphere. The mean value of ioniza- exist above any location and at any tion is changing from year to year in an time, as far as we know. The third orderly manner, and seems to move with and upper region appears separately the sunspot activity. Since the change only when the sun is directly overhead, in visible radiation from the sun appears merging into the next lower region negligible as activity increases, it would when the altitude of the sun is low. appear that there is much more activity When these two regions merge, the in the ultra-violet radiation, which causes this ionization in the atmosphere, a lower or F4 seems to take on the charac- coree- teristics of the outer F2 region, be- conclusion which has important coming more highly ionized. The major quences in the study of the tun. source of ionization in the two lower Since the last sunspot minimum the

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor June - July, 1938 Amateur Astronomy Page 65 percentage of ionization in the outermost times the upper regions may be entirely region of the ionosphere has increased invisible to the exploring radio wave more than 250 per cent, while a change because of the great intensity of this of 45 per cent was present in the lower ionization, and phenomenal radio trans- regions of the atmosphere for the same mission on ultra high frequencies occur. period of time. This not only empha- It h'as been also necessary to leave night sizes a difference in character of the effects entirely unmentioned. ionizing forces as already suggested, but It may be seen then that this outer imy1ies, on the basis of our hypothesis atmosphere of the earth, once so isolated of particle-bombardment, an enormous and inaccessible, is yielding to the exchange in the number or velocity of ploration of scientists now better equip- particles emitted from the sun as solar ped with more modern instruments for activity varies. So while data are lack- experimental work. Highly important ing, definite conclusion must await Oper- effects which might have been passed ation oer a longer period of time. over unnoticed have been discovered Deductions from the shorter period through observations at widely separated are not entirely speculative when we stations. rememher the close relationship between Despite the relative vacuum in the sunapot activity aid terrestrial magiet- outer reaches of the atmosphere, the ism and, in turn, the dependence of the events which occur there actually do earths magnetic phenomena upon the play an important part in the scheme of ionosphere. things. regions SOLAR ACTIVITY Changes taking place in these Folks are complaining about the static must have immediate effects in radio on their radios these days. A neighbor transmission and in the earth's magnetic with a set that has been giving good field, which depends upon them. service for quite a few years began police radio working on it but to no avail. Disturb- A few years ago certain ances are more noticeable on highly sen- stations were assigned to a frequency. of sitive sets it seems, for the reception is about 43 megacycles per second because as quiet as ever on small sets with, say, this frequency was high enough to pene- five tubes. The sun resembles the family trate the ionosphere. Therefore the range cat with the canary feather clinging of these stations was limited to their im- to his whiskers; it has a guilty look, as mediate vicinity. Today, as the result large spot after spot glide across its of the enormous increase of ion-density shining face. April showed a very ac- in the F2 region, these stations are fre- tive condition with large spots and spot quently heard in Europe. To provide a groups that tempt the astronomer-photo- minimum of interference to service, a grapher. knowledge of the fluctuations of the ionization in the upper atmosphere is es- Micrometer sential. The best frequency for trans- Appendix to the Trig mission across the Atlantic this year may D. F. BROCCHI not be the best next year. In "The Trig Micrometer" appearing In the case of a bright solar eruption in Amateur Astronomy for May, 1938, coinciding with certain geophysical ef- it was suggested that with an altazimuth fects, what really does happen? At the telescope a new setting be made on AB beginning of the eruption all refractions from time to time to reduce the error faded out suddenly, staying out for its due to the turning of the image. duration. When communication was It has been found that under certain again restored, the upper regions were conditions the rotation is quite appre- essentually the same as before the erup- ciable even during the three settings tion. This shows that the two upper made for one star in spite of fast work. regions were not affected, but the regions To test for rate of rotation, a second below 100 kilometers was so strongly setting is made on AB with working ionized that it completely absorbed the edge facing the interior, after the set- radio waves without reflecting them. ting of the third side. If there is s Mr. Berkner, in closing his article, noticeable difference between the two di- speaks of many observed effects which rections of AB, a setting on this side have not been mentioned, but which con- must be made for each star, which will tribute definite facts to aid in the con- serve as the first AB setting for that struction of the theory. There are, for star and the second AB setting for the instance, the sudden sporadic ionizations preceding one, with one additional AB of very great intensity at the 100 kilo- setting at the end of the nerformance. meter level. These can occur any time The third angle is found by adding of day or night, more frequent in sum- 180e to or subtracting 180° from the mer in any location, frequenting the po- second direction of AB, and subtracting lar region, practically never found at from the result the direction of the third the magnetic equator. During such (eontinaed on page 76)

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 68 Amateur Astronomy June - July, 1938 Irregular Variables for Observation ARTHUR L. PECK We notice as we read the heading on a number of the AAVSO variable star charts that the stars rated as irregular variables or at least that their periods are questionable. Upon investigation we find that many of the red stars vary within narrow limits, barely more than half a magrntude, and are not readily predicable. Alpha Herculis is an example, vary from 3.1 to 3.9 magnitude. The spectrum of this star, from Adams and Joy, is M5 with the calcium lines H and K brightest. Betelgeuse, the brightest of all the irregular variables, at times comes nearly to the splendor of Rigel. At other times it is hardly more than one third as bright. Gamma Cassiopeiae also comes under this heading. This star varies from 1.6 to 2.3 magnitude. During the last half of the year 1936 it brightened considerably. The standard magnitude of it had been 2.25 on the Harvard Revised Photometric scale, which is only slight1i fainter than Polaris. The star was found to be of magnitude 1.6 on Oct. 5, 1936 at Perkins Observatory, so members of the AAVSO immediately undertook bservations visually, and estimates of brightness varying between 1.6 and 2.2 were being reported from different stations within short periods of time. From L'Astronomie, P. Blaize reports an increase of light for the star, as of July 25, 1936, magnitude 1.85 based on observations with several comparison stars. No appreciable change from this value was noted by him over an interval of 11 days. W. H. Smyth, in his 1844 edition of the "Cycle of Celestial Objects," called attention to the sus.pected variation of Gamma Cassiopeiae by Sir John Herschel as far back as 1838. Scnyth states that he regrets that more attention had not been paid to this star, as a possible variable, rather than to Alpha Cassiopeiae. Alpha Cas- siopeiae has been suspected of variation for a long time and is listed in the largest catalogues with a range of half a magnitude (2.1 to 2.6) ; spectral class, G8. In the following table listed with several of the brightest irregular variables are the irregular variables from the AAVSO ôbserving list. Column 1, the designation; column 2, the star; column 3, the range in magnitude; column 4, the spectrum from Schneller, 1938; column 5, the color column 6, remarks. IRREGULAR VARIABLES Designation Star Range Spectrum Color Remarks Gamma Cass 2.1- 2.6 G8 5.8 Irregular Alpha Ori 0.6- 1.1 M2 7.3 2070d (?) Per. (P) Alpha Her 3.1- 3.9 MS 6.0 Irregular R Lyr 4.- 4.8 MS 4.1 Irregular ? Cep 4.0- 4.8 M2 7.0 Irregular 020356 UY Per 12.4-(16.0 .. U Gem Type 02.1258 T Per 8.0- 9.0 KS .. Irregular 021558 S Per 8.5- 11.0 MS 5.0 Irregular 051316 XX Tau 6.0-(16.0 Pec Nova (1927) 053005a T Ori 9.7- 12.8 R CrB Type 0S3005t An Ori 11.3- 12.0 Irregular 053326 RR Tau 11.0- 13.6 RW Aur Type 054319 SU Tau 9.5-(14.0 Goe 0.0 R CrB Type 060547 SS Aur 10.5- 15.0 Pec 0.0 U Gem Type 063308 R Mon 10.0- 12.6 1.0 R CrB Type 073520 Y Gem 8.5- 10.0 MOe Irregular 074922 U Gem 8.9- 14.0 Pec .... Irregular 081473 Z Cam 9.6- 13.0 G (?) Irregular

094836 U LMI 9.8- 13.0 . Irr. 280d Per (?) 154428 R CrB 5.9- 15.0 cGoep 0.5 Irregular 174406 RS Oph 4+- 11+ Ocp 4.5 Nova N.3 (1933) 184205 R Sct 4.5- 9.0 KSev 3.0 Irregular 146d Per (?) 191033 RY Sag 6.0- 1&0 Goep .. R CrB Type 201520 V Sge 9.S-(13.0 Ob . Irr. 309. Od Per. (?) 213843 SS Cyg 8.1- 12.0 Pec 0.0 U Gem Type 215717 U Aqr 10.0-(13.0 0.0 Irregular 232848 Z And 8.5- 11.0 Ocp 2.0 Nova (?) (1901)

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Irregular variables should be observed bell may be found in Annals, Harvard more frequently than the stars of known College Obse'rvato'ry 56,210. The spec- period. In fact they should be observed trum of this star is peculiar and is at least once each night. Sometimes it stated at times to resemble Class F. has been found of value to observe a However, little of the spectral charac- star such as SS Cygni each Julian Day teristics can be described in the iimited period when it is rising rapidly and also space that we have, considering their when it is fading. many peculiarities as noted by different Pickering separated a few stars which observers. are of a pecular character of variation SS Aurigae, the third star of this into two subdivisions. These he called group, is quite faint and has not been lib and lic, the first of which includes under observation long enough for the U Gem, SS Cyg, and SS Aur. Stars of collection of much data concerning it. class lib are characterized by a very However, data) are piling up regarding rapid rise from a constant minimum to this star, and with the continued obser- a maximum which does not last for any vation of the AAVSO members we will regular interval of time, being sometimes soon have a good history of it. long and sometimes short, and in turn The third division of the long period is followed by a slow decline to the mini- variables which we know as lic from mum. This change does not occur with Pickering was announced in Hwrvard any regularity, but is always unex- College Observatory Circular, 166, 1911. pected. This subdivision contains stars which U Geminorum remains at the mini- are ordinarily bright, hut sometimes for mum for a large part of the period, a year or more become faint without then without warning suddenly rises to warning, and vary irregularly until they its maximum brightness where it re- again attain their normal brightness. mains for a time and then gradually Three stars are in this class: R Coro- fades away to the minimum . This star nae Borealis, RY Sagittarii, and SU has been an object of much interest ever Tauri, Their spectra also are peculiar since its discovery in 1855 by Hind, an and subject to changes. English observer, for the suddenness R Coronae Borealis was discovered to with which it rises from the minimum. be variable by an English observer, Pi- Because of this characistic it should be gott, 1768-1807. It is typical of the watched constantly. This star is so three stars in its group. We, who have faint, even at time of maximum, that followed it through several years of ob- the spectrum has been only imperfectly servation, know that a drop to or near observed. It is usually described as minimum occurs at unpredictable inter- hazy and at times it resembles Class F. vals and comes when least expected. SS Cygni is a little brighter and has These three stars together with the three a shorter period than U (1emlnorum. It in the preceding group merit the care- is almost more favorably pced for ob- ful attention of all variable star observation and therefore has been stu- servers. died nlorQ extensively. A very complete 1982 No. 14th Street. discussion of this star by Leon Camp- Milwaukee, Wie.

Planetary Report No. 29 By E. P. MARTZ, Ir.. Director Planetary Section SUMMARY OP 1937 WORK OP THE PLANETARY SECTION report cannot pretend to and valuable work produced in this pe- The following of be more than a brief statistical survey riod by the relatively' small number of observations and reports turned in to communicating observers, and the re- the section director covering the work of sults point toward a fertile future for 1937. The vast amount of data pre- the Planetary and Lunar Sections. sented makes immediate and adequate 1.-Contributing Observers and Corre- analysis obviously impossible. However, pondents4 it is hoped that by the end of 1938 we 1. Walter H. Haas-10-inch refractor may be able to present in published at Mount Union College Observa- form a "Planetary Section Memoir No. tory, Alliance, Ohio, and 6-inch re- 1," covering the work of the section flector at New Waterford, Ohio. members during the four years from 2. Latimer J. Wilson-12-inch, 8-inch, 1935-1938. Any further planetary and and 4-inch reflectors from Nash- lunar observations made during this pe- ville, Tenn., and 21-inch Cassegrain- riod which have not yet been communi- ian reflector of the Jones Municipal cated to us will be gratefully received. Observatory at Chattanooga, Tenn., It is extremely gratifying to contem- of which Mr. Wilson was acting di- plate the great amount of conscientious rector.

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor June - July, 1938 Page 70 Amateur Astronomy during 1937: 3. Flugh M. Johnson-7-inch reflector tographic program from Des Dr. Dinsmore Alter, Director, Grif- and 8-inch refractor S. Moines, Iowa. fith Observatory; Dr. Walter Mount Wilson Ob- 4. W. w. Spangenberg 2.5 inch, 4- Adams, Director, - and 4- rervatory; Dr. E. C. Slipher, Dr. C. inch, and 5-inch refractors, Edson, inch reflector freni Schwerin, i. M., O. Lampland, James Brown Germany. Also 13-inch horizontal and Clyde Tombaugh of the Lowell telescope, and 24-inch reflector from Observatory; and the late Professor in Berge- William H. Pickering of Jamaica, B. the Hamburg Observatory Sec- dorf, Germany. W. I. Further, the Planetary is indebted to the f ol- 5. E. P. Martz, Jr.-60-inch reflector tion Director of Mount Wil- lowing for aid and discussion in un- and 6-inch refractor of son Observatory, and 12-inch Zeiss dertaking the present analyses of the Grif- the Mars and Jupiter 1937 Ihoto- apochromatic refractor Dr. George fith Observatory., in southern Cali- graphs and other work: fornia. A few desultory observa- S. Monk, Ryerson Physical Labora- the 24- tory of the University of Chicago; tions were also made with Director, inch refractor, and Mr. Clyde Tcm- Professor W. H. Wright, reflector .it and Mr. J. F. Chappell, photograph- baughs 12.5-inch, F:13, Dr. the Lowell Observatory, Flagstaff, er, of the Lick Observatory; Ariz.; with the 40-inch refractor and Arthur Adel and others at the Low- of the Yer- ell Observatory; Dr. Rupert Wildt, the 6-inch comet-seeker Observa- kes Observatory, Williams Bay, of Princeton University tory; Dr. Otto Struve, Director, Pro- Wis., and with the 6-inch refractor Jesse at the Students' Observatory of the fessor Frank E. Ross, Dr. University of Chicago, the last dur- Greenstein, and Professor Bengt of 1937. Stroemgren, of the Yerkes Observa- ing the fall and winter Donald Menzel of Har- 6. Lawrence Aller-Now a graduate tory; Dr. the Harvard College Ob- vard Observatory; Dr. Phillip C. student at Keenan of the Astronomy De- servatory; used the 12-inch refrac- Beutler tor of the Lick Observatory, Mount partment, and Dr. Hans G. Mars during of the Physics Department, of the Hamilton, Cal., on Chicago. 1937. University of 7. Dana K. Bailey-Rhodes scholar in astronomy at Oxford, England; 11.-General Discussion of Observations: verbally communicated observations A total of 3202 planetary and lunar of Mars in 1937, made with the 36- observations were received or reported inch reflector at Steward Observa- for 1937 from the nine co-operating ob- tory of the University of Arizona, servers though the vast majority of the Tucson. data was from the first observers listed, 8. J. Russell Smith-8-i och reflector whose names are wellknown to the read- and 2.5-inch refractor, from the ob- ers of the planetary reports. These observatory of Smyer High School, servations comprised the following: 654 Smyer, fex., Of which he is the di- drawings, mostly by Wilson, Haas, and rector and principal. Johnson. 238 photographic negative 9. A number of communications of in- films and plates by Wilson and the interest were received from the Rev. writer. Wilson took about 30 instantan- I,1r. T. E. R. Phillips, B. M. Peek, eous exposures of Mars on each of 81- and Henry McEwen, of the British roll film negatives, about 930 images, Astronomical Association and direc- and at least two lunar photos. The tors respectively of the Saturn, Ju- writer took about 6 time exposures on piter, and Mercury-Venus sections of highly enlarged scale of the planets on the B. A. A. The late Walter Good each of 205 cut film and plate nega- acre, Director of the B. A. A. Lunar tives, about 1230 images, and 32 lunar Section, also sent some B. A. A. plates; 591 miscellaneous observations of Lunar Section memoirs. Dr. Peter specific planetary and lunar phenomena, M. Miliman, of the David Dunlap for which no drawing or photos were Observatory, Toronto, Can., wrote of obtained. These comprise transit obser- spectra of Mars that he had taken vations, word descriptions, etc., each ob- with the 84-inch reflector in 1937. vers's results usually being in series 10. Letters indicating interest in be- and co-related. Finally, 1719 estimates ginning planetary observations were of relative intensities and colors of lu- received from James L. Russell of nar and planetary markings were re- Cleveland, Ohio, Phillip Fish of Su- ported by Haas and the students work- perior, Wis., and Rosario Casamen- ing under him at Mount Union Observ- to of New York City. atory. These were all made in the pur- 11. The Director is greately indebted to suance of specific observational programs the ±ollowing for aid and advice in on a limited number of sui jects. rt is undertaking his own planetary pho- worth while to call attention here to the

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor June - July, 1938 Amateur Astronomy Page 71 splendid energy and ambition shown ly servational and analytical work. It Mr. Haas, who reported 2263 observa- should be pointed out, however, that the tions in 1937, 836 of which were plane- figures given in this report represent tary. The other contributing observers only those observations which have either of the Section added 939 planetary ob- been communicated or reported to us by servations. the observers concerning 1937 work, and A survey of the above figures indi- that we are aware of a large number cates that nearly half of all the reported of as yet unreported observations for and communicated work was done on t e that period made by certain of the con- moon. Over half of the remainder (i.e.: tributing thservers. We cannot, of strictly planetary observations) was com- course, take account of them until they posed of observations of Mars in 1937, are communicated to us, and the writer about one-third of observations of Jupi- hopes that none of the contributing ob- ter, and the remaining one-sixth fairly servers will feel slighted if, in the re- evenly distributed among the other plan- port to follow, our record does not check ets and studies of planetary observing with that of the observer himself. We technique and seeing. If, as seems jus- are reporting only that work for which tifiable in view of the large number of we have definite evidence. lunar intensity and color estimates by IV.-Summary of 1937 Observational Work: Haas, the planetary photographic nega- 1. OBSERVING TECHNIQUE, SEE- tives are considered as contributing an ING, etc.: Though most of the ob- observation for each image recorded servers made experiments with, and (930 images by Wilson, 1,230 images by records of, these factors in the Martz) then we have a total of about course of other work, the only speci- 5100 individual and usable planetary and fic data on hand are 92 observations lunar observations contributed by the by Martz, covering a program to de- Section members during 1937. Of these, termine relations between seeing, about one-third were lunar observations, sky transparency (clearness), and and the remaining two-thirds planetary. the amount and height of fog layers Even so, it is still apparent that we are below the Mount Wilson and Grif- justified in having an independent Lunar fith observatories. Experiments in Observation Section, of which Mr. Haas the adaptation of various color fil- is the Director. ters and the development of tech- niques for their use in photographic IlL-Publications by Section Members and visual planetary and lunar ob- during 1937: servation were also made. Notices A total of 41 papers concerning the of the work of Haas and Martz on work of the AAAA Planetary and Lu- color sensitivity of the eye and ob- nar Sections were published either by servations of Venus appeared in members or others during 1987. Twenty- The Week's Science by Dr. E. E. three other papers, as yet unpublished, Free for February 15 and March have been r.eceived by the Director, mak- 22, 1987. ing a total of 64 papers. It should be 2. MERCURY: 44 drawings of the noted, however, that some of these pa- planet were received from Haas and pers and notes discussed 1936 planetary Johnson with accompanying word and lunar work, as well as that of 1937. descriptions of the observations and The majority of the papers were pub- specific phenomena. A paper pre- lished in the following journals: Amo.- senting the 1936 observations by teur Astronomy, Popular Astironomy, As- Hans and Martz with those of the tronomische Nachrichten, Das Weltall, British observers was published by Die Sterne, Die Himmelswelt (German McEwen in The Journal of the papers by Spangenberg), The Journal British Astronomical Association, of the Royal Astronomical Society of March, 1937. Cancda, The Journal of the British As- 3. VENUS: 95 drawings of the planet tronomical Association (paper by Mc- were received from Haas, Johnson, Ewen concerning Mercury work of Wilson, Spangenberg, and Martz. ilaas, Martz and others), and the Pub- Eleven photographic plates in red, liccitions of the Astronomical Society of yellow, green, and blue lights were the Pacific. The accompanying table in- made by Martz (66 images). 86 dicates the percentage distribution with miscellaneous observations were re- respect to subject matter of the papers ceived from Haas, Spangeniberg, and among the planets and moon and ob- Martz. serving technique and seeing researches. 4. MOON: 105 drawings were report- The table also indicates the percentage ed by Haas and Martz (Haas, 103). distribution of the 3202 observations and Johnson also observed specific cra- of the nine contributing observers among ters regularly. At least 34 photo- the subjects of research. The signifi- graphs were made by Martz and cance of this table is apparent and clear- Wilson. The lunar appulse of May ly indicate fertile fields for future ob- 24-25, and the lunar eclipse of No-

PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 72 Amateur Astronomy June - July, 1938 vember 18, 1937, were photographed and intensities of selected Jovian re- in red, yellow, green, and blue by gions. Martz. 233 miscellaneous lunar ob- 7. SATURN: Six drawings were com- servations were reporeed by Haas, municated by Haas and Spangen- Johnson, Spangenberg and Martz. berg. Seven photographic plates in Haas and his co-workers reported red, yellow, and green were obtained 1115 estimates of the colors and rei- by Martz (42 images). 17 miscel- ative intensities of about 30 speci- laneous observations were sent in fic lunar features suspected of ah- by Haas and Martz, and observa- normal changes. The more detailed tions were also made by Wilson and report of the Lunar Section for 1937 Johnson. Haas contributed 42 esti- will be presented by the Director at mates of colors on Saturn. Of par- a future time. We have on hand ticular interest is the blue tint ob- the Lunar Section Report for 1936, served a number of times in the which will be published in the near rings by Haas, Johnson, and Martz. future. Mr. Haas communicated it Such a color is called for by Schoen- to us some time ago, but various berg's theoretjcal photometyic analy- delays have occurred in getting it ses based upon particle size in the published to date. ring and angle of the incident light, MARS: 35 drawings of the planet and has been further indicated by were communicated by Wilson (243), R. W. Wood's photographs in 19Th, Haas, Johnson, Aller, Smith, and those of Martz in 1937, and others. 116 negatives Martz. photographic 8. URANUS: Five drawings and and plates were made by Martz and three miscellaneous observations of Wilson, comprising about 1440 ima- the planet were made by Haas. The ges. Wilson used Eastman p anato- color was distinctly greenish to him mic film on a 12-inch reflector, ob- as t is to other observers due to the taining the integrated color effect strong absorption in the red end of between 4000 A. U.-6500 A. U. the spectrum of the planet. Haas Martz photographed the planet si- belts on the yellow, green, recorded three faint multaneously in red, disk of the planet. and blue, using four appropriate * panchromatic and orthochromatic * * plates and filters, covering the en- In Planetary Section tire range with sorne overlapping: Director takes pleasure in expressing 3700 A. U.-7000 A. U. with 60-inch again his deep appreciation to all those reflector and 12-inch apochromatic who have helped make this and past Re- refractor. 55 miscellaneous observa- ports possible, and to record the sincere tions of Mars were received from hope that the contributing obseryers will Haas, Johnson, Wilson, Spangen- continue to communicate their work to berg, Bailey, Martz, and the Rev. us for a thorough analysis in the not Mr. Phillips of the B. A. A. Haas too distant future. made 254 estimates of color and intensities on the planet. Preliminary Percentage Distribution with Respect to considerations and tentative hypo- Subject of Publications, Observations theses have been published in Plan- and Observers, of AAAA Plane- etary Reports Nos. 22-27. Mr. Wil- tary Observation Section Dur- son's unusual observations and pho- ing 1937 tographs of bright flashes in the Papers Observations Observers southern polar cap on May 30, 1937. Subject: are worthy of especial note (Ama- 1. General pa- teu.s Astronomy, October, 1937, and pers and Popular Astronomy, October, 1937). observing JUPITER: 14 drawings were made. technique, by Haas, Johnson and Martz, and seeing etc. 18.7% 2.9% 11.1% (1) probably a number by Wilson and 2. Mercury 9.4% 1.4% 22.2% (2) others as yçt uncommunicated. 70 3. Venus 18.7% 4.4% 55.5% (5) photographic plates were obtained 4. Moon 18.7% 46.3% 55.5% (5) by Martz under identical condition 5. Mars 20.3% 25.3% 100.0% (9) as those of Mars above (about 420 6. Jupiter 9.4% 17.1% 44.4% (4) images). 100 miscellaneous obser- 7. Saturn 4.8% 2.3% 33.3% (3) vations were contributed by Haas 8. Uranus (notes, Johnson, and Martz, and in addition no specific the Rev. Mr. Phillips communicated papers) 0.3% 11.1% (1) longitudes of 55 observations of Total: 64 papers, 3202 observations, 9 prominent Jovian markings in 193 observers. as determined from transit observa- contributing -tiens by the B. A. A. observers. 726 N. Elmwood Ave., Haas made 308 estimates of colors Oak Park, Ill.

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official monthly publication of th. Optical Division of AAAA The R. WALLACE. Correspondw,t American Amateur Astronomical Association in a Publication Headquarters An interesting story appeared 1812 E. Curtis Place. Milwaukee, Wie. recent issue of Scientific Americen con- Societies telescope and observatory Affiliated cerning the Astronomical Society of Rutherford, N. T. of Mrs.. Marion Grant Bowen, Carson Asnateur Astronomers Association of Pittsburgh, City, Nev. The name of this observa- Pennsylvania. tory is the James A. Grant Observatory. Astronomers Guild of Jamestown, New York. is Chicago Amateur Astronomical Association, Chi- The brother mentioned in the story cago. Ill. none other than Jim Grant, honorary Eastbay Astronomical Association, Oakland. Calif. member of our group. Jim is a textile The Long Island Astronomical Society, Wantagh. and builder, and is N. Y. machinery consultant Louisville. Astronomical Society, Louisville, Kl. well known "way down South", Yes., suh! Madison Astronomical Society, Madison, Wis. The ingenious machine mentioned last Metropolitan Astronomical Society, New York, month for making our 21-inch mirror cir- New York. was de- Milwaukee Astronomical Society, Milwaukee, Wie. cular and beveling the edges, New Jersey Astrophysical Society, Woodbridge, signed by Lou Lojas of our group, and N. J. put together by Lou, Carl Grosswendt, Norwalk Astronomical Society, Norwalk, Conn. Ed Hannah, and Bob Cox. It has donc Optical Division of the AAA, New York, N. Y. a job that would be a credit to a high- Editorial Staff class professional shop. Miss Elizabeth Wight, Editor Lou's inventive ability again came to Mrs. A. K. Fisher T. R. Hedengren light in smoothing the edges of the E. A. Halbach Earl Needhsm bubbles. He used a brass round-head Advisory Editors screw fitted into a hand drill, and as he Prof. Leon Campbell - Variable Stars. he was assisted by Jim Grant who Prof. Charles P. Olivier - Meteors. drilled Prof. George Van Biesbroeck - Asteroids, comete. sprinkled water on the carbo. The disk and double stars. face has but one "decent" bubble-about Ten cents per copy, $1.00 per year. 1/4-inch diameter-and a few insignifi- Membership in AAAA, $1.00 per year cant ones, which will be considerably including subscription. lessened, we hope, as work progresses Send all communications to the above address with caibo, polishing, etc. There are a number of bubbles on the walls but Lou gave them his attention too, and the We wish more of our members would disk looks mighty clean. Incidentally, do something constructive with their the five-inch hole has been drilled from telescopes and go in for some specialized the back of this disk to within 'Is-inch work such as Roy A. Seely is doing. of the face. This work was done by Ed. His naine you often see in the columns Hannah and Jim Grant. of this magazine in connection with or articles. Carl Grosswendt has finished his prim- AAVSO observation reports By "constructive" I mean entering such ary and secondary for a 10-inch Caso. star, Any day now he will be testing the fields of service as the variable pifanetary, comet, etc. work and particu- secondary, and we hope he has the good obser- fortune of Join Guasch Tous whose larly making known the results of was perfect at First testing. vations and study in the columns of Ama- secondary teur Astronomy. Our group is now offering kits çom- tool, 12 grades On April 20 Dr. Richard N. Sutton, prising 8-inch disk and delivered a lec- of abrasives, pitch and rouge for the Haverford College, Pa., $7.25 to all and sundry ture with demonstrations on "Spinning modest sum of 4, William H. Barton, who wish to make mirrors at home. Bob Bodies." On May delegated to the job of executive curator of the Hayden Plane- Con has been tarium, where we have our headquarters seeing that tons of sawdust are placed on building so the rush for this and workshops, gave a lecture around the "Epochs and Eras." bargain will not result in emergency just for ambulances to attend those who Mrs. Helen Spence Federer has calls completed a 6-inch mirror for a New- may happen to get mangled or maimed focal length. or scratched in the crowd! tonian telescope, 43-inches Roy A. Seely made a RFT character- ictic of the quality of work he turns It hain't the 'eavy 'aulin' 'urts the out, and is busy making a fine eluatorial 'orse's 'oofs, but the 'ammer, 'animer, mount fitted with setting circles, etc.. 'amnier on the 'ard 'ighway. So say our for a gem of an 8-inch reflecting mirror. British cousins. But in our workshops The tube is round and of bakelite-so -it hain't the rub, rub, rub that 'urts you will understand that it will be a your 'ands and harms, but the 'ead- beautiful job when completed. Ed. Han- aches that come from finding a big nah had the honor of having his RFT scratch after many 'our's polishing and used during the eciipse expedition to ave to go back and grind, grind, grind. Peru. That was the recent event in the life PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor June - July, 1938 Amateur Astronomy Page 75

of our 21-inch. Ed Hanna, who has 'umble correspondent has started work slaved and slaved on the grinding and on the secondary for his 121/s-inch per- polishing, found, after bringing the mir- forated Casegrain and is greatly ap- ror to a 'beautiful polish, that a grain preciative of the help and advice given or two of catho had entered the trenches by Box Cox, Carl Grosswendt, Lou Lo- of his lap! Ed swears that Rufus is to jas (I have forgiven him. Don't ask blame. From this sad event comes a why!), Ed Hanna and William Mason. moral-don't do your polishing in a room Selah! where grinding is done. So, profiting Hayden Planetarium, from this experience, we have now en- :&ew Yrk City. closed the mirror in a separate room under lock and key and the polishing is going ahead with a merry swing. The inscription on the door reads: Tri State News Notes "A bondon hope CHESTER B. ROE. Correspondent All ye that here uninvited." Our speaker for the May meeting was -Dante and Ed Hanna. Dr. Lee Devol, research associate of the Our member Roy Seely has been at- glass research department of Mellon tempting to make a telescope mirror by Institute. He lectured on "The Theory deposting copper and nickel on a fin- of Glass Polishing." ished. mirror and coating the metal mir- Just how much we amateurs owe to ror with rhodium. This unorthodox the untiring efforts of Albert G. Ingalls, method results in a fair enough mirror Editor of Scientific American's amateur which might be improved by refining astronomy department, we will never the process. Mass production of Schmidt know. Due to his alertness, the Pitts- camera mirrors without labor seems burgh group now has an instrument for a dream. Let us hope the result will locating strains in glass. This instru- not be a nightmare. The first mirror ment was described in the April issue of made by him using this method was Scientific American, and is the invention shown to the AAVSO at its spring meet- of Horace Dall of Luton, England. Af- ing in Providence, R. I., and he de- ten reading the article, one of our mem- scribed the process briefly. bers wrote to England for detailed in- In connection with his College Course struction and we now have an instrument at C. C. N. Y., Carl Grosswendt com- for detecting strains. We take this op- pleted an aluminizing apparatus. and is portunity to thank Mr. Ingalls for his coating mirrors. Mrs. Helen Lane is industry, and the space alloted to Mr. now figuring her 6-inch mirror. Mrs. Dall's article. If you contemplate grind- Charles A. Federer has just completed ing a lens or mirror, you may save a fine 6-inch mirror, but is afraid that much future grief by having your glass hubby will grab it for a shaving mn- blanks tested. Make your arrangements nor! Dr. Edward G. Clifton works away with Leo J. Scanlon. silently at grinding a 6-inch Gordon 6-inch. Max Mat- The June meeting of the Pittsburgh Raisbeck is making a group was of great interest. We look tes, after exasperating attempts to get forward to an rid of a hill in his 8-inch, finally took active summer. Visits to Lou Lojas' advice and made a new la several oservatin stations are on mirror came schedule and a number of telescopes and BINGO! a beautiful have just been completed that will help back from Evaporated Films Company, to make these more Ithaca, N. Y. According to Bob Cox, visits interesting. Lou Lojas, Ed Hanna and Carl Gross- In time for tl.ese fine summer even- wendt, the 10-inch Cassegrain just com- ings are: A 6-inch by Dr. J. L. Wag- pleted by John Guasch leaves nothing to oner an 8-inch by W. R. Wickersahm, a be desired. Th.ey are raving about it. 4-inch refractor by H. B. Boose. Dr. A. And William Burdian is finishing up a L. Runion, the oldest member of our 4-inch R. F. T. for spotting Rdbert group, has completed a fine 8-inch pyrex Nelson not only made a beautiful para- and is now working several 4-inch flats bolized 8-inch mirror, but made a rug- preparatory to making a 10-inch this ged mount of novel design with wood- coming winter. Dr. Runion is well past seat tube, and he is now installing a eighty. Our youngest member, William clock drive. Devine, of fourteen years, is also hard John Luce, Jr., is the essence of pa- at work, having just completed an ex- tience. but he is being rewarded with cellent 6-inch Richfield. Another 6-inch a fine 8-inch mirror, and his father for Richfield, made by C. W. Kelly:, goes the fun of it made a honey of a mirror into use shortly. from a castor from the five sand dime We were unfortunate in the loss f store. Is that the world's smallest te]e- one of our most active members: The scope mirror? If it isn't, let us know. Reverend Father F. J. Sullivan has com- and he'll see what he can get from a pleted his studies at the University of piece of glass the size of a dime! Your Pittsburgh and is now permanently lo- PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor Page 76 Amateur Astronomy June - July, 1938 cated at St. Bonaventure College, Alle- on red variables. He told us of his re- gany, N. Y. search, showing slides of it, and inform- One of the outstanding achievements ed our group that if we would like to of the Pittsburgh group was the recent cooperate, there would be plenty of op- completion of a 6-inch mirror. Now, a portunity for us to work out an observ- 6-inch mirror is nothing in itself, but to ing program with him which would be complete this one required reams and of real interest and value both to him reams of paper, dozens of pencils, and and to us. many bottles of liniment for the treat- As the sky was clear, the rest of the ment of writer's cramp. Albert Slacen- evening was taken up observing with ski has finished this mirror, all instruc- the 13-inch 'scope in the building and tions had to be written out for him, a the many other instruments belonging tribute to the patience of those who to our members which were scattered helped this young man. Albert, you see, about the grounds. is a deaf-mute. May we extend our invitation to all Valley -View Observatory, our friends and readers of Amateur Pittsburgh. Pa. Astronomy to visit us; you will be more than welcome at our observatory. MAS News Notes M. N. FISHER, Correspondent The Milwaukee Astronomical The June meeting comprised not only our annual picnic but also-and more Society Observatory important-the dedication of our newly (continued from page 63) completed observatory. the of amateur astrono- this event were sent thering interest Invitations to my. out to both professional and amateur all over the country, although The sooiety wants to thank all of its friends so well over 100 members and outsiders mibers and friends who have given were able to be present. Mo-re than wholeheartedlly of their time, money an-d twenty drove up from Chicago, about materials, and regret that it is not pos- ten from Madison, six from Waukesha, cible to list the individual contributions. Wis., two from Iowa, to say nothing We are pleased and gnateul to have of those from other neighboring places. the observatory and invite our friends to observe with us. was preceded by a pic- and the pthlic The dedication 2346 N. 47th Street, nic supper, which was planned and pro- Milwaukee, Wis. vided by Mrs. De La Ruelle, the wife of the late founder of our society, with the cooperation of her helpers and of the household of Prof. M. J. W. Phillips Appendix to the Trig Micrometer near whose farm our observatory is situated. (continued from page 65) The meeting itself, held outdoors in side. The angles are then adjusted by front of the building, began when it was subtracting from each 1/ of the differ- dark enough for slides to be seen. Our ence between their sum and 180 if the president, Edward Halbach, presided; field is in the northern hemisphere, or Prof. Phillips made the dedicatory ad- by adding the like amount if it is in the dress, which included a brief history of southern. As a check, the sum of thc the building of the observatory, illus- adjusted angles should be 1200. trated by lantern slides of the various stages in its construction; Dr. S. A. Barrett, head of the Milwaukee Public Museum and a long-time friend of the Society, spoke, an-d a few other special friends from out of town gave brief congratulatory messages. The main address was presented by Dr. Charles Hetzler of the Yerkes Ob- servatory, who has done unusual work

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