Parks in the Canadian Cordillera *

Home , Bow Range, Mount Robson, President Range, Roche Miette, Storm Mountain (Canada)

360 SCIENTIFIC AMERICAN SUPPLEMENT No. 2083 December 4, 1915

Mount RundIe at Banlf, showing monoclinal structure with escarpment on the A Icene in Yoho Park, Mount Stephen on the right and Cathedral Mountain face typical of the eastern ranges of the Rocky Mountains. on the left, taken from Burgess Pass.

Physical Features and Attractions in the Canadian National Playgrounds

By John A. Allan

, CANADA set aside her first mount.ain reserve for the is 11,870 feet, seen in the Matterhorn of tlle Canadian of a series of sharply defined ridges all parallel to onu benetit and pleasure of the people in 1887. To-day there Rockies-Mt. Assiniboine. another which present a steep esearpment on their are eight national playgrounds in the Canadian Cordillera Physiographically there are three very distinct struct eastern face and a more genUe slope toward the west. between the Great Plains and the Pacific Ocean . Rocky ural features to be observed within this park. The'first These ridges are huge uptilted fault blocks of rock, the Mountains Park, Yoho, Glacier and Revelstroke Parks of these is the sharp line of demarkation between the low more westerly blocks having been thrust partly over the are situated on the main line of the Canadian Pacific rounded ridge of the inner foothilIs and the gray massive block in front of it. The rocks in these fault blocks range llililway; Jasper Park and Mt. Robson reserve are along Iimcstone mountains, void of vegetation and lightened essentially from Devonian to Cretaceous in age. The the Grand Trunk Pacific Railway; Waterton Lakes Park by patches of snow manteling tl>e upper slopes of the mountains in the western one third of the park are much lies south of the Crows Nest line; and Strathcona Park massifs. This break between these two physically dif older and belong to the pre·Cambrian and Cambrian is situated toward the center of Vancouver Island. ferent units is marked by an almost perpendicular periods. These formations have been up-arched into a 2,500 3,000 Three of these parks are in Alberta, the remaining five escarpment, to feet high. So sharp is this broad fold which defines the backbone of the Rocky are in British Columbia. break that it is possible to walk along the extreme eastern Mountains system, as weil as the continental watershed. Rocky Mountains, Yoho, Jasper, Mt. Robson aml hase of the Rock")' Mountains. This f('ature is partil� The rocks in this portion are for the most part Iying 49 52 Waterton Lakes Park lie within the Uocky Mountain ularly noticeable between latitudes and degreps. nearly horizontal. 'l'here is a sharp break which is re system of the Cordillera; whereas Glacier Park is in the This escarpment marks the front of an overthrust block presented by a fault between the YOllnger formations on Selkirks and Revelstroke Park is along the edges of tbe which when the mountains were uplifted was thrust in the east and the older formations on the west. The rocks Selkirk and Columbia ranges. pi aces several roiles over the plains to the east. At the within this park are entirely of sedimentary origin. From a scenic point of view these parks are all different base of the escarpment ia exposed the overthnlst fault Banff and Lake Louise (Laggan) although only 34 and yet aU attractive in various respects. Each of these which farther south is called the "Lewis Thrust." miles apart are very difforent as to locatiun and scenery. pleasure grounda will be brießy mentioned. Within the eastern edge of the park along this fault the The former is situated in the second range of the Rocky Cambrian beds are thrust over the lower Cretaceous Mountains, on tbe ßoor oE the Bow VaUey at an elevation THE ROCKY MOUNTAINS PARK.1 formations. of 4,542 feet above sea-level. Banff is the beadquarters The Rocky Mountains Park of Canada is the largest The otber two structural features of note within tbe of the park with inclosures containing aU varieties of and .Dldest of the Dominion national playgrounds. By park a.re to be found in the mounta.ins themselves; two mOlmtain animals including several buffalo. It also an Act of Parliament in 1887 an area comprising 260 thirds of the eastern slope of the Rocky Mountains consist contains a museum, meteorological station, headquarters square miles was "reserved and set apart as a public of the Royal North West Mounted Police and the only park and pleasureground for the benefit, advantage and food distributing center for the entire park. enjoyment of the people of Canada." In 1902 this Lake Louise is situated at an altitude of 5,670 feet reservation was enlarged to include 4,900 square mHes, above searlevel and 533 feet above the railway at but as this was found to be too large an area to preserve Laggan. The scenic features are kuly Alpine, consisting . properly, tbe boundaries were reduced in 1911 to inclose of a valley closed at one end by 11. glacier, surrounded by 1,800 square miles, wbicb is the present size of this world rugged mountains of ßat-Iying quartzites, limestones known playground . and shales, whose summits average over 10,500 feet, and Tbis reservation lies entirely on the east slope of the fringed with perpendicular cliffs or more gracefully Rocky Mountain system in tbe Province of Alberta and curved slopes heavily timbered. The fioor of the vaUey extends from tbe western edge of the plains westward contains a lake of matchless beauty and the outlet of to tbe summit of the Rocky Mountains, which is also the the valley hangs 600 feet above the ßoor of the Bow continental watershed. valley. This park includes the entire drainage basin of the The bighest and most prominent mountains are found Bow River witbin the Rocky Mountains and has roughly on or close to the continental divide. The most lofty the form of an isosceles triangle with the base nmning peaks include Mt. Assiniboine (11,870 feet); Mt. Temple in a northeast and southwest direction. The gateway to (11,626); Mt. Hungabee (11,447); Mt. Victoria (11,355); the park from the plains is also a natural portal to the Mt. Deltaform (11,225); Mt. Lefroy (11,220); Mt. Ball mountains and is known as the Gap. (1O,825); Mt. Balfour (10,731); Mt. Fay (10,612); Mt. This reservation is commonly known as "Banff Park" Aberdeen (10,340); Storm Mountain (10,309). sinoe it includes the town of BantT, one of the best known Among the many lakes of special individual scenic and most popular mountain tourist resorts in N orth beauty tbat attract the tourist are Louise, Minnewanka, America. Vermilion, Bow, Hector, Spray, Sbadow and Moraine Banff and Lake Louise, both weU known resorts in the Lake in the valley of the Tean Peaks. Canadian Rockies, are the only two distributing centers Within the limits of the park there are 300 miles of ror tourists within this park. trails wbich are frequently traveled, and over 125 miles The Rocky Mountains Park contains many features of carriage road .. The government has taken steps to that would attract the general public, tbe nature lover, . eneourage trail travel by the erection of cabins at various the artist or the scientist. It embraces the most rugged, points along certain trails. A telephone system is also picturesque and majestic part of the Canadian Rockies � being installed. many lakes with superb, artistic setting, the sulphur A motor road is being constructed from the plains to hotsprings at Banff, and above aU a museum of scenic the coast. It is already complet,ed through this park beauty so extensive and so varied that it equals any in and crosses the continental divide at Vermillion Pass, the world. The contrast of fot"e8ted lower slopes, rock fifteen miles west of Banff. barren, towering escarpments and pinnacles, capped with YOHO PARK. snow and ice, and lakes large and smaU nestling in a forest or in a rock face, offer variety and enchantment to Yoho Park, containing about 560 square miles, is the visitor. Tbe topograpby of the park is rugged and situated on the western slope of the Rocky Mountains diatinctly Alpine in eharacter. The lowest valleys reach adjacent to the Rocky Mountains Park. Tho Kicking down to 4,200feet above sea-Ievel, whilo the highest peak Horse River, rising on the conti/wlltal watershed at the A perfect reftection of Mount Assiniboine seen pass oC the same name (Iocally (,-8lled the Great Divide), • Courtesy or Science Ct7MpIcflU. in Lake Magog. Note the "ierd face-Iike form of divid68 the park almost through the center. Tbe grade apubUsllld b1 permissioD or the Oeolos!ealjBune1, Otta1l'a. .ome ferocious anima. when viewed from the 8ide. of �he upper,an of the river 18 very .te&pioat one point

near the pass, in a distance of 2 % miles there is a differ be visited by aß tourists; the Illecillewaet and Asulkan rounded and weIl forested. The broadened river course ence in elevation of 900 feet. glaciers, and the Nakimu caves. Both are reached by forming Jasper and Brule Lakes and the meandering Y oho Valley, the largest tributary from the north, good trails. Within a few minutes' walk from the railway braided character of the stream in places add beauty to shows distinct evidence of the handiwork of the glaciere. it is possible to stand on the frontal lobe of a real living the landscape when backed up by a forested slope ter Takakkaw Falls, nearly 1,200 feet high, and Twin Falls, and moving glacier. This gives one an opportunity to minating in a massive gray limestone escarpment, with about 500 feet high, entering the Yoho from either side, study glacial phenomena in the process of change. well-nigh perpendicular walls. Roche Miette is a good rank among the most superb in the continent. Both are The Nakimu caves (caves of Cheops) are situated in a example of this. formed in massive middle Cambrian limestones and both cirque-like basin toward the head of Cougar Creek on The topography of the ranges west of Jasper is quite come from typical hanging valleys inclosing glaciers. the west side of the Illecillewaet Valley. These caves are distinct from that to the east. A line crossing the railway The Yoho glacier closes the northern end of the valley. wonderful in their formation. They consist of a series of about two miles east of Jasper and drawn in a northwest The many peaks in the President range on the west and irregular subterranean channels which have been formed southeast direction divides the younger portion of the the Wapituk range on the east, present a panorama truly by running water from a crystalline limes tone. There Rocky Mountains consisting largely of westerly tHted majestic. have been several miles of these tunnels explored and monoclinal fault blocks of Devonian to Cretaceous rocks, Mention can only be made of such places of particular they furnish an interesting and somewhat eerie expedi from the older portion represented by Cambrian and scenic interest to the tourist as the Ice River Valley tion to the visitor. A considerable portion of the park older rocks that make up the ranges which mark the sUITounded by such peaks as Mts. Goodsir (11,676), still awaits the explorer and adventm:er. continental watershed. This structural feature is similar Vaux (10,881), and Chancellor (10,751); Ottertail Valley; Game is abundant, especially the grizzly and black to that more fully described under the Rocky Mountains McArthur Pass and the Cataract Valley with Lake bear, whereas the more open mountain slopes offer a Park. McArthur, Lake O'Hara, Mt. Odaray (10,165), Cathe museum of floral variety for the botanist. A pbysical feature that is making the park weIl known dral Mountain (10,454), Mt. Biddle (10,876), Mts. JASPER PARK. is the presence of sulphurous hot springs (Miette hot Hungabee (11,447); Huber (11,041); Mt. Victoria Jasper Park, although still quite young, is year by year springs) situated toward the eastern end of the park about seven miles from the railway in the valley of Fiddle Creek. There are several of these springs' and the temperature varies to a maximum of 127 deg. Fahr. The water in some of these springs has been proved to have certain medicinal properties for rheumatics.

MOUNT ROBSON RESERVE. Mt. Robson Park reservation is under the control of the Province of British Columbia; it therefore is not a Dominion park. This reservation joins Jasper Park on the west and includes the ranges to the northwest of Yellowhead Pass, forming the continental watershed. This park is still comparatively young and has not yet been thoroughly explored. It however, contains some of the most majestic and rugged scenery in the continent. Mt. Robson, "the Monarch of the Canadian Rockies," has an altitude of about 13,700 feet above sea-level. It is tbe most lofty peak in the Canadian Cordillera south of the Yukon. There are a number of other peaks in the Robson group equally as magnificent, but mucb lower in elevation. Associated witb these summits are many square miles of glaciers and snowfields that add beauty to the panorama. Berg Lake and Lake Kinney are two beautiful large sheets of water at the base of Mt. Robson; they are con nected by the Valley of a Thousand Falls. The rocks in this district are chiefly pre-Cambrian and Cambrian in age and are all of sedimentary origin.

WATERTON LAKES PARK. Berg Lake and Robson Glaeier, in Mount Robson Park. Continuous movement in this glaeier, espe Previous to 1914, this was the smallest Dominion eially in summer, is evideneed by the ereaking and groaning sounds whieh it makes. mountain reservation, having an area of 16 square miles.

(11,355), and many other peaks over 10,000 feet in the Bow range which forms the continental watershed. All of these mountains are readily accessible and can be climbed by the aspiring mountaineer. Mt. Stephen (10,485) one of the best known, can be easily climbed, and from its summit a magnificent panorama can be viewed. On the north slope of Mt. Stephen there is a small lead-zinc mine located 1,000 feet almost ver tically above the railway. Geologically this park is especially unique. Along the railway there is exposed one of the thickest Cambrian sections in the world. The total thickness of a con tinuous conformable series of quartzites, limestones and shalcs from the base to the top of the Cambrian was found to be over 18,500 feet.' The rocks in the park are a11 sedimentary with the exception of a small area of igneous (plutonic) rock exposed in the Ice River Valley. These rocks are alkaline in composition, ranging from nephelite and sodalite syenites, through ijolites and urtites to jacupirangites and other basic affinities. These rocks Qave been fully described by the writer in the memoir mentioned above. The mineral sodalite has a beautiful blue color and is much in demand by tourists as souvenirs. GLACIER PARK. Glacier Park comprises an area of 468 square miles and is situated at the summit of the Selkirk range. This reservation is the most westerly of the three situated on Mount Assiniboine (11,870 feet), the "MaUerhorn of the Canadian Rockies," in Rocky Mountain Park. the main line of the Canadian Pacific Railway. IWgers Scenery typical of the range forming the continental watershed. Pass, the summit of the Selkirks, is located about the center of the park. becoming better known. This reservation is situated on -It has since been enlarged to include 432 square miles. The scenery in Glacier Park is equally grand as that the Athabaska River west of Edmonton and comprises This park is situated in the extreme southwestern of the Yoho or the Rocky Mountains Park, but it is an area of 1,000 square miles, which includes a strip 20 corner of the Province of Alberta. It is bounded on the nevertheless quite distinct. The mountain peaks are miles on each side of the railway and extending from the west by the continental watershed, on the east, for the more numerous and more pointed in form than those in foothills west to the continental watershed on either side most part, by the eastern face of the Rocky Mountains, the Rocky Mountain system. This difference of form of Yellowhead Pass which also marks the western bound on the north by Township Five and on the south by the can be accounted for geologically. The rocks Me essen ary of Alberta. International boundary line. tially pre-Cambrian in age and consist of schists, slates, The position of Jasper Park in relation to the Rocky Waterton Lakes Park adjoins the United States gneisses and other metamorphie types badly contorted Mountains is quite similar to that of the Rocky Mount Glacier National Park which has been deseribed in and broken. This portion of the Selkirks represents the ains Park 200miles to the south, in that they both occupy Bulletin No. 600 of the United States Geological Survey. old teITain from which much of the sediment was derived the entire eastern slope of the mountain system from the Although this reservation has not yet become weIl which' gave rise to the great thickness of Cambrian and plains to the continental divide. known on account of the lack of roads and trails, yet it other Paleozoic formations in tho Rocky Mountains. Thc topography in .Jaspcr Park, although by no means iA hound to bocome a popular resort especially for the Two physical features are of special note, and should 80 rugged and precipitous as that in higher altitudes to citizens in Southern Alberta. One of the principal • Allan, J. A� Geology or the Plaid Map Area-Memofr 66' the BOuth, is nevertheless attractive, pleasing and varied features at preaent in the park ia the oha.in of lakes after GeoIoslcal SurTeT or Oan�a. 19U. in its oharaoter, The va.lley of the Athabaaka. iabroadly wbioh the park haa bean DADled, The upper Waterton

Lake extends for about three miles south of the Inter of the town of Revelstroke on the main line of the Although little is yet known of much of the park, cach national houll!lary. Canadian Pacific Railway. lt is located on the extreme season is bringing 'it before the public, and showing that This chain of lakes is walled in by steep promontories western flank of the Selkirk range on the ea,stern side of this reservation is worthy of being ranked as equally and rock escarpments which rise to an elevation of 8,000 the Columbia River. wonderful in the works of nature as other parks referred feet. The lower lake lies just outside of the mountains The park is being opened up rapidly by the con to above, which are situated far inland and in lofty and is separated from the middle. and upper lake by a struction of trails and a motor road to the top of Mt. mountain ranges. broad delta of alluvial material carried down hy Blak Revelstroke. This peak is only 6,500 feet high, yet from Buttles Lake affords a picturesque watercourse 25 miles iston Creek (Pass Creek). The lakes within the mount its summit there is a magnificent panorama towards the long and 1 to 2 miles wide, winding down the center of ains are entirely or glacial origin. There am other equally Selkirks, the Gold ranges, the Cariboo distriet and up the park. Streams often v.ith waterfalls enter on either picturesque lakes within the park; of these Summit Lake the Columbia valley. An endeavor is being made to side through heavily timbered shores which terminate in (Oil Lake) lies in a large cirque elose to the continental make this park a popular winter resort. rugged rocky slopes often snow-clad and cold. divide and extends across the houndary line into the Campbell Lake consists of two basins, the lower being STRATHCONA PARK. United States. This lake is drained by on Creek, so 7 miles long and 172 miles wide, while the upper one is called hecause small quantities of crude petroleum have In .June, 1!H0, the government set aside an area com about 6 miles long. been obtained in three or four drill holes in this valley. prising approximately 260 square miles to be used as a N'lmerous small lakes which, like the larger ones, are The scenery within the park is typical of the eastern reservation and playground in the center of Vancouver of glacial origin, add charm to the surroundings. part of the Rocky Mountains. Island. This area was called Strathcona Park. Since the Tbe topography on the whole is rugged since the There are no true glaciers, but large patdws of per original limits of the park did not include much of the altitude ranges from sea-level to nearly 7,500 feet. Elk ennial snow may be seen on many of the higher slopes. finest lake and mountain scenery, the government in horn Peak, about 7,200 feet, is known as the Matterhorn Very little is yet known of the northern half of the park. 1913 extended the limits of this reservation to include of Strathcona Park. about 800 square miles. 'l'he flora of the park has been studied by James M. REVELSTROKE PARK. Strathcona Park is situated about the center of Van Macoun of the Geological Survey of Canada. He reports Revelstroke Park is the youngest and smallest of the couver Island; the northern gateway is about 120 miles having noted at least 350 species of phenogamous plants Canadian Cordilleran playgrounds. It was set aside in north of Victoria, 75 miles west of Nanaimo and 20 miles in the park which are very representative of the whole June 1914 and consists of 48 square miles in the vicinity north of Alberni. flora of British Columbia.

Potassium Photo-Electric Cells-II*

A Study of the Relationship of Illumination and Current

By Herbert E. I ves

[Concluded from SCIENTIFIC AMERICAN SUPPLEMENT No. 2082, Page 350, November 27, 1915]

COMPARATIVE RESULTS OF SEVERAL CELLS. possible in any one cell to obtain all types of curves by tion must, in these cells, be considered as of similar With the apparatus as described under section 4, mere vol tage change. For instance, the two extremes effect to voltage variation. The data of cell j (argon a large number of miscellaneous illumination-current exhibited in cell a (concave upward) and cell e (concave filled) indicate similar stepped curves, due to illumination curves were taken for all the cells above described. down ward) are not attained in cell c at the extreme variation. These were made with different applied voltages. At voltages used, other phenomena entering to interfere The next step in the study appeared to be the in first the aim was to use one voltage throughout, and one at the high voltage and lack of sensibility preventing a tentional variation of electrode distance and pressure, was selected which would not cause a dark discharge in study of lower voltage effects. the factors not variable in the completed cello any of the cells. Afterward it became evident that the Differences of pressure, of gas, of electrode distance, Cell with variable electrode distance.-The easiest factor phenomenon under study was a function of voltage, so of surface, exist among the cells, and it is to these that to vary and, as it was thought (noting the results of some extra curves were made at different voltages. we must look for explanation of the phenomena. These Stoletow), the most likely to show in the results, was At various times during the experiments on high re differences have been rooorded in the description of the electrode distance. A special cell was, therefore, con sistances, curves similar to Fig. 3 were ohtained from cells. Arlditional evidence as to the different electrical structed, shown in Fig. 6 (g). Tbe platinum electrode cell a. As long, howeVl'r, as polarization and other conditions holding in the cells is afIorded by the voltage was attached to an iron rod which slid in a glass tube, troubles were not entirely eliminated these results could current curves (made subsequently to the illumination and was connected by a fine coil of cop per wire to a not be accepted as conclusive. current curves) for a chosen medium illumination. These platinum wire sealed in the glass and going to the bat Had no other cell been at hand, the conclu5ion could show differences, ascribable to different pressures and teries. The cell was first filled in a horizontal position weil have been drawn that this is the true relationship electrode distances, which are as extreme as those be and sealed off at the best vacuum obtainable with the between photo-electric current and illumination. The tween the illumination-curves, which they resemble in Gaede mercury lamp, the iron rod was then held in posi opportunity afforded by the possession of several cells, some ways. tion by a selenoid, the cell turned to the upright position, however, made it possible to demonstrate that �he phe A study of previous work on the photo-electric effect17 and the potassium melted and flowed into its final place. nomenon is much more complicated. Each of the several shows that curves possessing nearly all the characteristics The electrode was afterward easily put in any desired cells shows a different illumination-current relationship. of the cells experimented with, have been obtained position by inclining and tapping the tube. Curves both concave and convex, of most extreme type, where the variables were voltage, electrode distance, and Two curves obtained with the cell, for electrode dis as weil .as some with double curvature, appear. It ap pressure, illumination being maintained constant. J. J. tance of 2 and 40 millimeters, are both concave to the pears, too, that the relationship is, to a varying degree, Thompson18 develops two equations, the first dealing illumination axis, and while the short-distance curve is in different cells, a function of the applied voltage. with the conditions well below the voltage, pressure, somewhat less concave than the other, it is evident that In no case is this relationship linear. If only a com and electrode distance at which discharge occurs in the variation of electrode distance alone, at this pressure, paratively short range of illumination be used, few points dark, and the second with the conditions near the point does not produce rapid changes in curve type. taken, and a certain volta ge range not overstepped, of discharge. From the first of these equations it fol Cell with variable pressure.-A cell similar to g was next curves may be obtained which appear to be straight lows that for low voltages the current should obey Ohm's constructed, differing in the possession of a side tube lines. When compared with other curves of the same law, for higher voltage saturation would set in. From containing a ground stopcock and a ground cone, fitting family, that is, obtained with higher and lower voltages, the second of these equations it follows that the current the ground sleeves of the pump system h. This cell the points which deviate by amounts apparently within should increase, owing to ionization by collision, accord was made a little differently from the last, being filled the errors of measurement are actually found to be true ing to a power of e determined by electrode distance, etc. in an upright position through a lateral constricted tube, indications of curvature. Furthermore, with the cells As the most conclusive summary of these results it the solenoid being in position throughout. Of course j and k, in which the nearest apparent approach to line may be said that the reasoning and equations just quoted the proper procedure would be to have the cell constantly arity was round on first measurement, the observations are applicable to the present case if variation of illumina connected to pump and gage, but this was not possible were repeated many times,running up and down the tion and variation of voltage are considered as similar to arrange in the present case. Trouble was expected curv'es, proving the curvatures to be real and ol signifi in influence. But certain peculiarities of these illumina from the stopcock, and leakage did, in fact, spoil the canee. The four curves of ceU j are obviously develop tion-curves are not to be overlooked. The voltage potassium surface after two days. In that time, how ments of each other. Cells such as j and k might easily current curves of cell c show at the lowest illumination ever, it was possible to allow the �urface to reach a bteady be hastily assumed to show the heretofore believed linear apparent complete saturation; at slightly higher illumina state after its first rapid drop in sensitiveness and to relationship. Only the refinement of measurement tions approach to saturation and subsequent increase run several curves at several press ures of hydrogen. The called for by the requirements of photometrie applica ascribed to ionization by collision. But at higher illu change in pressure was made by replacing the cell on tion would make clear with these particular cells that this minations the increased current again approaches satura the pump, securing a good vacuum, and introducing gas is not so. Fortunately, the extreme differences among tion, making a saturation-curve with a depression. At rrom palladium foil. Measurements were made as soon all the cells leave no doubt of the exceptional and acci still higher illumination this depression disappears and after as practicable. Resulting curves were made at dental character of the linear relationship when found. a simple characteristic curve is obtained, apparently the three pressures 0.01, 0.06, and 0.6 millimeters, and, approaching saturation uniformly. These data are of while by no means offering a complete picture of the SUGGESTED REASONS FOR THESE RESULTS. interest in connection with the characteristic curves for variation of the illumination-current relation, show clear A study of the illumination-current relationship shows the inert gases, recently published by Franck and Hertz,19 ly that it is a function of pressure, voltage, and electrode that in any one cell the relationship is a function of the which show a series of steps. distance. From the results of Va.rley it is to be expected applied voltage, although to a varying degree in dif The most striking feature of the illumination-current also that the nature of the gas filling the tube will affect ferent cells. Thus, the variation in character or curve curve of cell c is the series of steps shown at higher volt the relationship, in cell c, in going from 2 to 348 volts, is much greater ages. These steps, caused by varying illumination, are Two generaHzations appear to be justified from study than in cell k. It is evident that different voltages cor similar to the voltage-current curve steps just referred of these curves: respond in d�fferent cells to different characteristic curves. !� to, and are additional e� ��.

1t B .• • From tbe ,48tro PhJ/8ical Journal. erichte der Deutsch. Phl/s. Gesel 20, 929, 1913. B. The course of the changes from the most intense

VOLUME LXXX] NEW YORK, DECEMBER 1915 [10 CENTS A COPY NUMBER2083 4, $5.00 A YEAR

TWIN FALLS IN YOHO VALLEY, CANADIAN ROCKIES.-[See page 360.]