1266 MONTHLY WEATHER REVIEW. AUGUST,1910 ary since the last of July. While the river at Red Bluff averaged MOUNT= SlTllS FOR OBSERVATORIES ON THE slightly above the low water of 1908, it waa, with this exception, PAUIFIU SLOPE. the lowest ever recorded during any month. Below Red Bluff, By A. G. MCADIE. especially in most of the reaches between Colusa and Knights It was the writer’s privilege to be a member of Doctor Camp- Landing, there was little interruption in the fall of the river dur- bell’s expedition to the summit of Mount Whitney in August, ing the month. 1909, when certain spectroscopic studies were made of the at- At Colusa the Sacramento averaged 1.1 foot, which is 1.4 foot mosphere of Mars. The site was selected, after some prelinii- below the August normal stage, and 1.2 foot below the low water nary investigations by Messrs. Campbell and Abbot, because it of 1908. is practically above the level of the water vapor of the atmos- At Knights Landing the zero stage was reached on the 9th of phere. This virtually eliminates absorptive effects due to dust. the month, and on the 31st a stage of 0.3 below zero was re- haze, water vapor, and other matter prevailing in general in the corded, which is the lowest stage ever before noted at this point. lower air strata. The elevation is 4,400 meters and the general At Sacramento the river averaged 0.1 foot above the previous climatic reputation one of clear weather and extreme dryness. lowest monthly average, which was in September, 1908, ancl2.4 Mount Whitney is historically familiar because of Langley’s feet below the August! normal stage. At this point the fall was early work on the transparency of the atmosphere and his frequently interrupted by the titles, which, in some cases, amounted to a rise of as much as 0.4 foot. Below Sacramento determination of the value of the solar constant. Langley’s there was little departure from the summer stage, except that work was carried on not. at the summit, but some 600 meters the effects of flood tides were more marked than usual. below, over on the Kern side, at what is now known as Langley’s In some of the reaches the Sacramento has left its usual sum- Camp. In 1909 Abbot! repeated to some degree the earlier 01)- mer channel, and, as a result, navigation has been renclerecl diffi- servations, using, however, the summit. His is the first use of a complete bolometric outfit at an elevation above 4 kilometers. cult,andfrequent groundings have occurred among the large craft. The station has again been occupied during the present season The Yuba River at Marysville averaged over 1 foot below the by Abbot and doubtless some valuable solar energy curves were usual August stage, and was 0.8 foot lower than the previous obtained for comparison with those made at, lower levels. lowest average for the month. The run-off in the numerous Acting on the recommendation of Messrs. Campbell and forks of this stream was markedly deficient, so much so that it is Abbot, Dr. C. D. Walcott, Secretary of the Smithsonian Insti- reported that several mines have been compellecl to close on tution, aut-horizedthe construction of a small stone building on account of the scarcity of water. the summit, and this shelter is now available for astrophysical At Oroville the Feather averaged 1.4 foot below the usual purposes. The erection of this shelter is in line with the develop- August stage, and nearly 1 foot below the lowest previous ment of high-level observatories in America. The establish- monthly average of which there is a record. At the close of the ment of the Lick Observatory may be said to mark the begin- month all the feeders of the Feather River carried less water ning of the movement in favor of sites whwe research could be than they have ever been known to carry before. conducted under atmospheric conditions markedly cliff ereiit The American River at Folsom averaged 0.6 foot below the from those where the great astronomical observatories of tlie normal August stage, and was 0.3 foot lower than the low water world were situated, namely, at low levels and near centers of of August, 1908. The run-off of all streams in the headwaters population. Harvard Observatory early recognizecl the value of this river diminished very slowly during the month, and the of high-level sites and established observing stations in South American itself exhibited an unusually sluggish condition, there America. The inauguration of the Solar Physics Observatory being a range of only 0.1 foot between the highest and lowest at Mount Wilson is but a progressive development and clearer stages. recognition of the necessity of carrying on work where there is San Joaquin watershed.-All reports received from streams in the greatest possible freedom from the atmospheric clisturbances the drainage basin of the San Joaquin cluring August show a so common at low levels. steady but gradual decrease in the water supply, and, in some Primarily the degree of definition or clearness of seeing will cases, exhibit lower gage readings than have ever before been determine the reputation of both observatory and observer. recorded. The Stanislaus at Melones averaged over 3 feet below The astrophysicist is handicappecl by his inability to get away the zero of the gage. The Mokelumne at Electra averaged 0.1 from earth; or to get out of the convectional region, i. e., from below zero, and the Tuolumne at Jacksonville averaged 0.3 foot the surface up to the region of constant temperature. If it were above the zero of the gage. The Merced River at Mercecl Falls possible to work at an elevation of about 11 kilometers, it would averaged 0.8 foot below the zero of the gage and 0.4 below the be found that the “load,” as it may be called, of foreign matter lowest previous average for the month of August. in the atmosphere is practically nil, and that the several gases The San Joaquin River itself was markedly below its usual are distributed according to their molecular weights. The so- August stage from Pollasky to Lathrop, but from Lathrop to the called isothermal region is one in which there is no vertical con- lower islands there was little departure from the normal summer vection; and also, because of the absence of water vapor, one stage. where absorption of solar radiation is a minimum. Professor SMOKE FROM BURNING FORESTS. Turner has pointecl out that such conditions must materially The British ship Dunfemnline, which arrived at San Francisco affect refraction. from Newcastle, Australia, , 1910, reports that the Recent discussion of the amount. of water vapor in the atmow- smell of the forest fires was noticed when the ship was 500 miles phere of Mars shows the need of some better knowledge of the from land. The odor of burning wood was quite unmistakable amount of water vapor in the lower air strata. Water vapor is and officers of the ship stated that they expected to find evidence present to the estent of 1.2 per cent of the total gases at the sur- of a great conflagration upon reaching port. The haze from the face of the earth (according to Humphreys’), and decreases forest fires made it impossible to get an observation for about rapidly with increase of elevation to an imperceptible amount 10 days. at or below 10 kilometers. It is plain, therefore, that for proh- The observation is of unusual interest because the prevailing lems connected with planetary atmospheres, as well as solar and winds in this region are from the west or northwest. During the stellar atmospheres, and for work bearing upon solar radiation, morning hours, however, there is a gentle movement of the lower the greater the altitude, other things being equal, the more accurate the work. If one stops to consider the irregular dis- air from the land seaward. It seems hard to realize that the _- ~ --_. smoke should have been carried so far from the land. ’ Mount Weather Bulletin, Vol. 2, Part 2, p. 66.

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tribution of heat near the ground, the marvel is not that defini- MEETING OF THE SOLAR RESEARCH UNION AT MOUNT WILSON, CAL. tion is sometimes poor, but that the wave front is not more dis- The International Union for Cooperation in Solar Research torted and to such a degree as to prevent anything like good held its Fourth Conference at the Mount Wilson Solar Observ- definition. This is especially true during the day hours and for atory, California, to September 3, 1910. Previous some time after sunset. The convectional currents resulting meetings of the Association were held at St. Louis, Oxford, and from differences in temperature due to radiation, and, in a small Paris. The next meeting will be held at Bonn in 1913. The degree, conduction of heat near the surface undoubtedly affect following members of th; Fourth Conference were present at. seeing. The best seeing, as a rule, occurs during the early Mount Wilson : morning hours. Doubtless a curve could be developed showing Prof. J. 8. Ames. Johns Hopkins University. . Baltimore. Id. Prof. Charles G. Abbot, Smithsonian Astrophisical Washington. D. C. a close relation between seeing and instability of the lower air. Observatory. This is a matter of importance in solar work when conducted on Prof. Walter S. Adanis. Mount Wilson Solar Observatory, Mount Wilson, Cd. Prof. Harold D. Babcock. Solar Observatorv. Mount Wllson Cal. mountain sites; and, especially if, as in the case of Mount Whit- Prof. J. 0.Backlund. Observatoire de Poulkovo, Poulkovo. Russia. Prof. E. E. Rarnard. Yerker Obnerratory, Williams Bav ais. ney and other peaks in the high Sierra, there are steep walls or Prd. A. Brlopolaky. Observatoire de Poulkovo, Poulkovo. Rieaia. precipitous sides favoring the development of strong afternoon Prof. Jean Bosler. Obwrvatoire de Mrudon, Meudon. . Prof. F. P. Brackett. Poniona College, Claremont. Cal. ascensional currents. Miss Cora C;. Bura.ell. Solar Obeervatory. Mount Wilson, Cal. Prof. W. W. Can~pbell. Lick Observatory. Momt Hamilton. Cal. Hale, in discussing the conditions on Mount Wilson, shows Prof. C. A. Chant. University of Toronto. Toronto. Canadn. that the seeing is best during the early niorning hours, although Prof. Henri Chretlen. Observatoire de Nice. ...Nice. France.... Nev. P. R. Cirera. S. J.. Obwrvatorio del Ebro. Tortosa, Spnln. frequently good in the late afternoon: Dr. W. W. C'ohleots. Bureau of Standards. Washington. D. C. Rev. A. L. Cortlc. S. J., Stonyhurst College Observatory, Lancashire. England. Shortly after sunrise the sun's limh is serrated, hut this effect hwonim Irw Prof. A. Cotton Ewle Normale Huprieure. Paris. France. and lesn marked as the sun's altitnde increms. Zlsually at this time in tlie Prof. H. Deslandres. Observatoire de Meudon. Meudon. France. morning the atmosphere is almost perfertly calm and rloudlms. The seeing Prof. N. Donitch. Observatolre de I'Universite, St. Ptershurg. Russia. Prof. Frank L. Drew. Solar Obsevatory. Mount Wilson. Cal. usually improves and reaches a msxiniuni, where it remains for sonic tinic. Prof. F. W. Dyron. Royal Observatory. Edinburgh. Sroilind. The effect of the heating of the mountain then beromes apparent and tlie Prof. Ferdinand Ellernian, Solar Observatory. Mount Wilson Cal. definition deterioriates. Disturbances at the suds limb under these condi- Dr. P. Eversheim, University of Bonn. Bonn. Grrniady. Prof. Chss. Fabry. Vniversity de Marseilles. Marsrilles. Franw. tiom do not resenihle those .seen immediately after sunrise, but have a flut- Dr. Edward A. Fath. Solar Observatory. Mount Wllson. Cal. tering appearance, which we are accustomed to speak of as the heating effwt. Mrs. W. P. Fhmlns, Harvard College Observatory, Cambridge. Mass. In the late afternoon the seeing usually improve, hut is rarely very good at. Prof. F. E. Fowle. Smithsonian Astrophysical~~ Washington. n. C. midday. This is not a rule yithout exception, however, we have some- Observatory as Prof. A. Fowler, Imperial ~011ekof .s ciencr' and South Kensington times recorded nearly perfect definition during the hotht hours of the ~lsy.~ Technology. London. England.' Dearborn Observatory. Evanaton. 111. The particular class of disturbances here referred to is proba- Yerkes Observat.ory. Willlanis Bay. Wis. University of Chbago. Chicago. Ill. bly caused by ground heating effects. The instability of the Throop Polytechnic Inst.itut~, Pasadena. Cal. air may be effective up to a height of 100 meters. There is Solar Observatory. Mount Wllson. Cal. Solar Obwrvatory. Mount. Wllson. Cal. another class, which will be referred to later, where the insta- Prof. M. Himy. Observatoire de Pari., Paris. Franw. Prof. J. Hartniann. Iioenigliche Htema.arte, Aachcn.Goettingen. Germany. Germany. bility of the air occurs at a much higher level and is not directly Prof. K. Haussnisnn. Technkhe Horhchule, caused by earth heat. Poor definition, caused by the first of the Prof J V IIep rger, Imperial 0b.servatory. Vienna, Austrla. Ma& E. i-l. HIE. 34 Prlnee's Garden, London. England. above-named conditions, can, to some degree, be counteracted Prof. W. J. Huniphreys. U. S. Weather Bureau, Washington. D. C. Professor Idrac. Obwrratoire de Muedon. Meiidon. Franre. by mounting the telescope at an elevation of 20 or more meters Prof. J. C. Kapteyn. Astronomical Laboratory, Cronln n. Holland. above the ground. Hale has shown that at a height of 25 meters Prof. H. Iiavser. rniversity of Bonn, Bonn, !&many. Dr. Arthur &. Iilng. Solar Observatory. Mount Wilson. Cal. there is a marked improvement in definition. He has also Prof. H. Iionen. Phvaikalisches Institute Hdenigliche Sternwarte,' demonstrated beyond criticism the value of modern construc- Lowell Observatory. tion and design in the prevention of irregular heating of the air Roval Society. Bohr Observatorv. column. 1Tniversit.vof California. Berkeley, Cal. Prof. H. C. Lord. Emerson hlcMillin Obsrrvntory. Columbus. Ohio. Finally, in selecting a mountain site for an observatory, one Prof A G McAdie IT. H. Weather Bureau, Ran Franeiwo. Cal. must consider the effect of storni frequency. In this respect the Dr. iVdter' M. Mitchell. Detroit Observatory:. Ann Arbor. Mich. Prof. H. F. Nemdl, l'niversity Ohservatory, Canibridpe Eo lnnd. mountains of California, south of the Tehachipi, have a marked Prof. F. 0.Pease. Solar 0bservat.ory. hlount ~i~don.$81. Prof. E. C. Pickering. Harvard College Observatory. Cambridne Mars. advantage over mountains in other sections of the country. J. 8. Plaaket.t, Esq., Domlnion Observatory. Ottawa. Ca'nada. C:onite A.de la Baume Pluvinel. 7 Rue de la Baum~, Paris. France. Few storms pass that way. This means that there is less Prof. E. Pringsheini. l'niversitv of Brrdaii. Brrdau. Germany. stratification of the air ancl in general better clefinition, provided Prof. P. Puiseur. Obwrvatbire de Paris. Paris. Frnnre. Prof. A. Rireo. Oaaervatorlo 4strofiriro. ('atania. Slclly. the telescope is mounted at some height. With the passage of Prof. W. G. Ritchev Solar Observatory. Mount Wilson. Csl. each cyclone and anticyclone, ascensional and descensional cir- Rev. J. 8. Ricard. k: J.. Hanta Clara. Cullegr. Mnnta Clara. Cal. Prol. A. L. Rotrh. Blue Hill OI>wrvat~iry, Hydc Park. Mars. culations are established and not infrequently marked tem- Dr. Herny Norrls Rurwll. Princet.un t1niversit.s. Princeton. N. J. Prof. J. R. Rydhem. Vniverslty of Lund. I.und. Sweden. perature inversions occur. There mag he an inversion of teni- Dr. Charleb E. Mt. John. Holm OhNerratory. Mount Wilwn. C'nl. Prof. Fernando Sanford. Htanlord University. PdIJ Alt.0. CS1. perature close to the ground, ancl, at the same the, another T)r. Frank Schl~singrr. Allegheny Olmerratory, Allr~hcny,Pa. inversion at a considerable elevation. One may be clue to fiolcl, Prof. Arthur Srhustcr. Vict.oria Park. Alauchestar. Englnncl. Prof. K. ~chwarrschild. Aatrophyaikalirchr-sC)lis~rra- Potsdam. Gemmany. slow-moving air currents near the earth's surface; while another toriuni. may be due to the approach of the warm center of an area of Prof. F. H. Scared. Solar Observatory. Mount Wil~on.Cal. Dr. V. M. S1iphc:r. Lowell Observatory. Flagstaff. Arix. high pressure. Recent investigations of the free air have Prof. Frederick Slocuni. Ywkcs Obrrvntory. Williain~Rav, Wis. Miss Rut.h E. Smith. Solar Ohservatory. lfount Wil& C~I. brought to light the fact that up to a level of about 3 kilometers Prof. S. W. Rtrntt.on, Bureau of Standards. Washiugton. 1). c'. Prof. Ii. Striive. !ioenigliche Sternm.arte. Berlin. Germany. regular temperature gradients or gradients approximating the Prof. R. D. Townley. Stanford University. l'alo Alto. CUI. adiabatic rate of cooling are the exception rather than the rule. Prof. H. H. Turner, University Observatory. Oxford. Eneland. Miss Louise Ware. Solar Observatory. Mount Wilson, Cal. We have an almost incessant warming of air clue to compression Miss Phoebe Wnterman. Solar Observatory. Mount Wilson. Cal. Prof. F. R. Watson. University of Illlnois. Cham aim. Ill. of descending masses on the one hand and a cooling of air clue to Prof. H. C.Wllson. Doodsell Observatory. Nort.hield. linn. expansion in rising, and the whole materially niodifiecl, espe- Prof. A. Wolfer. Sternwarta des Eidg~nossierhen Zurivh, Hwitzcrlacd. cially in the lower level by the water vapor present. Polytechnikunis, The highest efficiency, therefore, is to be obtained by the The Mount Wilson Solar Observatory was established as a establishment of observatories in regions where there is a mini- Department of the Carnegie Institution of Washington in 1904. mum, both of storm action and of vertical circulation, where There is now in operation a 60-inch reflecting telescope with a inversions of temperature are infrequent and where there is a primary focus of 25 feet and mirror combinations, giving equiva- lent foci of 80, 100, and 150 feet. Used wit.h t.his telescope are minimum amount of water vapor. - ____ -- Study of Conditiorw for Solar Rwnrch nt. hlount Wilson. Yearbook various stellar spectrographs. The Snow horizontal telescopc No. 3, Carnegie Institution, page 170. has a mirror of 24 inches aperture and a focal length of 60 feet

Unauthenticated | Downloaded 09/30/21 02:22 AM UTC 1268 MONTHLY WEATHER REVIEW. AUGUST,1910 This telescope is used with an 18-foot solar spectrograph. There Spectroscopic study of the motions of vapors in sun spota-Mr. St. John. is also a 5-foot spectroheliograph for direct photography of the Spectrwopic investigation of the rotation of the sun as determined by the sun. The tower telescope has an objective of 12 inches aperture displacements of lines of different elements.-Mr. Adam. and 60 feet focal length. A 30-foot solar spectrograph, also a Comparison of the spectra of the center and limb of thc min.-Mr. Adams. 30-foot spectroheliograph are used in the study of sun-spot Direct photography: spectra, the investigation of solar rotation, and the spectra of Of nebulrp and star cIusters.-Mr. Ritchey. the chromosphere and center and limb. A second tower tele- Of the Kapteyn Selected AreasMr. Fath. ' scope has an objective of 12 inches aperture and 150 feet focal Investigations in photographic photometry.-Mr. &ares. length, giving a solar image 17 inches in diameter. In order to Hpcdrwopic investigations: get a wider range of dispersion new instruments are in course of Of nebulze and star clustms.-Mr. Fath. Of bright stars under very high dispersion.-Messm. Hale, Adams, and construction. Babcock. The machine shop, instrument, ancl optical shops and the Radical velocity inveqtigationsof faint stars with low dispersion,includ- physical laboratory are located in Pasadena. These are well ing parallax stars and Orion type stars.-Messrs. Adam and Bab- equipped. The new 100-inch mirror will be figured and ground cock. in the shops. A list of the investigations in progress or recently Electric furnace investigations of the effect of varying temperature on completed at Mount Wilson includes the following: spectra.-Mr. King. Daily direct photographs of the sun, spectroheliograms in calcium and General work on arc and spark spectra under a great variety of physical con- hydrogen light, and special spectroheliograms with high dispersion, for ditions.-Mr. King. the general investigation and classification of the flocculi and pronii- Complete study of the Zeenian effect through (t large range of wave-lengths nencea, including structure at different levels, effect of absorption, pos- for various spectra, and tats for polarization, etc., for special spectrum sible influence of anomalous refraction, and relationship to sun+pots.- lines -Me8srs. King and Babcock. Mmrs. Hale and Ellerman. Study of the effects of pressure on spark spectra, with special reference to Law of solar rotation as determined b the motions of the hydrogen and enhanced lines.-Mr. Gale. calcium flocculi.-Mews. Hale anJEllerman. On the absorption of light. in space.-Mr. Kapteyn. Daily areas of calcium flocculi, and comparison with records of terrestrial magnet.ism.--Mems. Hale and Ellerman, -in cooperation with Dr. Statistical investigations relating to stellar evolution.-Mr. Kapteyn. Hakcr. Study of spwial groups of star streanis.-Mr. Kapteyn. A general investigation of solar magnetism, including determinations of The meeting decided by unaninlous vote to enlarge the scope polarity and field strength for various elements and at different levels of the work carried on by the solar union,to include research in within and outside of sun-spots, inclination of axis of theelectric vortex: rotation of plane of polarization by spot vapors, relationshi of polarity astrophysics as as physics. to structure of hydrogen and calcium flocculi.-Messrs. Hag, Ellerman, It was also unanimously agreed to adopt a standard scale of and Babcock. wave-lengths, to be known as the Intern tional and the unit A general investigation of sun-spot spectra, including wavelengths and usecl to be known as the International ln@,rom. Repods origin of spot lines, cause of weakened and strengthened linw, etc.- were received from various colnmittees on various questions on Messn. Hale and Adams. Photographic investi ation of the spectrum of the chromosphere, including solar rotation. Comniittees were appointed on standard wave- anj of bight lines, cauSe of displmements, etc.- lengths, nieasurenient of solar radiation, spectroheliographic Mpasrs. Hale and Adams. investigation of the spectra of sun-spots, eclipse observations, Absolute wavelengths of the H and K lines.-Mr. St. John. and determination of solar radiation. General circulation of the solar calcium vapor aa indicated by the displace- The accompanying illustrations are reproduced through the menta of the H and K lines.-Mr. St. John. courtesy of the Sierra Club.

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FIG.3.-Abhot’s Spectrobolometer for determining solar constant. The summit of Mount Whitney, 11,502feet. (From photograph by Dr. W. W. Campbell.)

FIG. 4.-Eastern face of Mount Whitney from Lone Pine Trail. (From photograph by U. S. Department of. Agriculture.) Face of cliff, 2,000 to 3,000 feet shear.

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