would be subject to severe inundations. Indeed a flood from this cañada did destroy a large part of the town in 1623. The whole line of the barranca is intersected by ravines similar in character to this cañada, and it is these which produce the broken jagged outline of which I have spoken. I have found it impossible to select a fitting place for the observatory, where the grounds could be unbroken by these gullies, and care will be needful to prevent the descent to a lower level of much of the soil which has been given us.

The wind is very rarely from the east, and I am informed that it has never been known to be due west; a circumstance doubtless attributable in great part to the barrier presented by the magnificent Sierra west of the city. The winters are very chilly, even snow being not infrequent, although ice does not form. Even now while roses, cactuses, cassias and white lilies are in full bloom, the young peaches of half their full size, and the grapes well formed, -the mornings are uncomfortably chilly, and no one thinks of wearing other clothes than woolen. Yet before the sun is an hour high, and until he has gone down in the west, his beams are simply intolerable. The foreigner who goes about or exercises in the sunshine between 12 and 2, is sure to rue it, and the natives never commit such an indiscretion. The astronomer, whose exposure is by night, finds himself for once at a vantage in the fiery Argentine summer. Yet the air is not so hot as the torrid climate would suggest; and the nights even in midsummer are cool.

The dryness of the air has impressed me quite as much as any other climatic peculiarity. A bowl of water left uncovered in the morning is dry at night; ink vanishes from the inkstand and becomes thick almost by magic; the bodies of animals, left exposed, dry up instead of decomposing; and at other times than during, or immediately after a rain, neither active exercise nor exposure to the sun's rays cause a perceptible perspiration.

We are suffering no small embarrassment from the non-arrival of our books and instruments from Germany. The Meridian circle, clocks, chronometer, photometer, etc., were all on board ship at Hamburg, when the war was declared, and up to the last advices, although the blockade of the Elbe had been raised, no vessel for the River La Plata had ventured to leave port. Should another month pass without their arrival it would be a serious drawback to us. Meantime there is plenty of work to be done in superintending the building, and making the numerous preliminary calculations for places of standard stars, tables of reduction, etc. Should the meridian-circle be long delayed, the time might be well employed in making such a Uranometry for the southern sky as the absence of a photometer will allow,-on the same plan as Argelander's, and as my unpublished northern one, made at Albany in 1858. The temporary embarrassments of the Government-treasury, occasioned by the serious and destructive insurrection in Entre Rios, may slightly retard our progress, or at least render it less easy for the necessary means to be provided, especially since the carpentry has arrived in so unfortunate a condition; but that cordial desire to facilitate our work, which clearly animates all parties here, will doubtless reduce difficulties of this sort to a minimum while they continue, and render their duration as brief as may be.

THE

AMERICAN

JOURNAL OF SCIENCE AND ARTS.

[THIRD SERIES.]

ART. XXIV.—On the Discovery of actual Glaciers on the Mountains of the Pacific Slope; by CLARENCE KING, U. S. Geologist.

WESTERN explorers have usually confined their labors to the more accessible altitudes; indeed it is only within the last ten years that the higher portions of the great West have been studied. One remarkable feature of the extreme elevations is the absence of glaciers. Wide areas of mountains whose average altitude and configuration are equivalent to the glacierbearing mountains of Switzerland have been found to be covered here and there by deep fields of perpetual snow, similar in character to the névé of the Alps. The whole topography of the loftier Cordillera within the United States has been modified by glaciers now extinct: vast moraines flank the higher gorges; accumulations of gravels and sands, erratics, rches montonnées, and the finest possible instances of polished rock abound wherever a considerable mountain mass is lifted above nine thousand feet. It is almost startling to observe the freshness of these indications. Travel where one will in the bigh Sierras or in the more elevated regions of the Rocky Mounains, he seems to be treading the pathway of a glacier of esterday. A future study will, without doubt, clear up the entire chronological relations of the ice occupation of these anges. The studies of Professor Whitney and his corps in the heights of the Sierra Nevada have developed a series of Tinct glaciers equaling in all respects the former grandeur of the Alpine system; yet with the exception of one or two imentary masses of ice, nothing is left in the Sierras but

AL JOUR. SCI.-THIRD SERIES, VOL I, No. 3.—MARCH, 1871.

the fields of perpetual névé snow. Very remarkable in depth and area as these are, they are not sufficiently extended, nor is there enough winter accumulation of snow, to start a glacier movement. Singularly too, the heights of Colorado prove to be even less snowy than the Sierras. The névé masses are less, and they waste much more during the dry season. The Wind River, Wahsatch and Uintah ranges have been examined by the writer, and although the extent of lofty peaks is very great, they are even less snowy than the heights of the Laramie range in Colorado. A comparison of the average annual temperatures of the Cordillera north of latitude 36° clearly shows that the climate is not too warm for the existence of glacier masses, and that the small precipitation of snow is due chiefly to the lack of moisture in the air. This entire region is swept by an almost invariable west wind, whose lower strata have been deprived of their moisture by the warm ascending currents of the valleys, and, although the peaks of the mountains are lifted into this wind, the actual amount of moisture is too small to create a great piling up of névé. Accordingly the summit region is characterized by the absence of glaciers and a tendency of the entire flora to ascend into higher altitudes than at corresponding Alpine stations. A single point lifted to a great height is not sufficient to form a great condenser. A widely elevated region is necessary for the creation of great local storm systems; the two parts of the Cordillera, therefore, where we should most naturally look for glaciers are the Mount Whitney region in the Sierras of California, and the high group west of Denver. Professor Whitney, in his description of the former, calls particular attention to their absence. The writer was one of those who made the exploration of this region, and was as much impressed as any one with this remarkable lack.

In early September, 1870, with a small detachment of "the U. S. Geological Exploration of the 40th Parallel," acting under the orders of Maj. Gen. Humphreys, I visited Mount Shasta in northern California, for the purpose of making a detailed survey of the lava systems which flow eastward from that peak, and connect themselves with the basalt regions of the Nevada Desert. On September 11th, we climbed to the top of the lesser Shasta, a conical secondary crater jutting out from the main mass of the mountain on its northwest side. The party consisted of Mr. S. F. Emmons, Mr. F. A. Clark, Mr. A. B. Clark, and Mr. Sisson, the well-known mountaineer and guide of the region, and the writer. We carried our phys ical and topographical instruments, our fur beds, and provisions for four days. In the afternoon at about half past one o'clock we reached the rim of the cone, and looked down into a deep gorge lying between the secondary crater and the main mass of

Shasta, and saw directly beneath us a fine glacier, which started almost at the very crest of the main mountain, flowing toward us, and curving around the circular base of our cone. Its entire length in view was not less than three miles, its width opposite our station about four thousand feet, the surface here and there terribly broken in "cascades," and presenting all the characteristic features of similar glaciers elsewhere. The region of the terminal moraine was more extended than is usual in the Alps. The piles of rubbish superimposed upon the end of the ice indicated a much greater thickness of the glacier in former days. After finishing our observations upon the side crater, and spending a night upon the sharp edge of its rim, on the following morning we climbed over the divide to the main cone, and up to the extreme summit of Shasta, a point 14,440 feet above the sea level. From the crest I walked out to the northern edge of a prominent spur, and looked down upon the system of three considerable glaciers, the largest about four and a half miles in length, and two to three miles wide. On the next day we descended upon the south side of the cone, following the ordinary track by which earlier parties have made the climb. From the moment we left the summit we encountered less and less snow, and at no part of the journey were able to see a glacier. An east-and-west line divides the mountain into glacier-bearing and non-glacier-bearing halves. The ascent was formerly always made upon the south side where, as stated, there are no glaciers, and this is why able scientific observers like Professor Whitney and his party should have scaled the mountain without discovering their existence.

Before and after the ascent of Mount Shasta, a week was given to an examination of the southern half of the volcano. Since the earliest settlement of Strawberry and Shasta valleys, there has never been such a complete denudation. From June to November, the snow masses were less than they have ever been seen before. This favored very greatly our geological observations, and gave us an excellent opportunity to study the relics of the former great névé. We explored one after another all the cañons which, approximately following the radius of the cone, are carved to a greater or less depth into the lava-flows. From the secondary cone around to the eastern side of the main mass are only occasional fields of snow and ice-bodies of a thousand or two feet long, usually quite narrow and lying on the more shaded sides of the ravines. In nature and texture they are quite similar to the true glacier ice, possessing in all cases planes of stratification which indicate the pressure of the formerly overlying masses. There is little doubt that all the scattered snowfields, that, in the months of August and September, dapple the southern slopes, are the relics of glaciers. They

are found in the region of the ancient névé, but extending downward into what was formerly the zone of movement.

Upon reaching the eastern side we found in a deep cañon a considerable glacier, having its origin in a broad névé which reaches to the very summit of the peak. The entire angle of this glacier can be hardly less than 28°. It is one series of cascades, the whole front of the ice being crevassed in the most interesting manner. Near the lower end, divided by a boss of lava, it forks into two distinct bodies, one ending in an abrupt rounded face no less than nine hundred feet in height. Below this the other branch extends down the cañon for a mile and a half, covered throughout almost this entire length with loads of stones which are constantly falling in showers from the cañon walls on either side. Indeed for a full mile the ice is only visible in occasional spots where cavities have been melted into its body and loads of stones have fallen in. From an archway under the end a considerable stream flows out, milky, like the water of the Swiss glacier streams, with suspended sand. Following around the eastern base of Shasta, we made our camps near the upper region of vegetation, where the forest and perpetual snow touch each other. A third glacier of somewhat greater extent than the one just described, was found upon the northeast slope of the mountain, and upon the north slope, one of much greater dimensions. The exploration of this latter proved of very great interest in more ways than one. Receiving the snows of the entire north slope of the cone, it falls in a great field, covering the slope of the mountain for a breadth of about three or four miles, reaching down the cañons between four and five miles, its lower edge dividing into a number of lesser ice-streams which occupy the beds of the cañons. This mass is sufficiently large to partake of the convexity of the cone, and, judging from the depth of the cañons upon the south and southeast slopes of the mountain, the thickness cannot be less than from eighteen to twenty-five hundred feet. It is crevassed in a series of immense chasms, some of them two thousand feet long by thirty and even fifty feet wide. In one or two places the whole surface is broken with concentric systems of fissures, and these are invaded by a set of radial breaks which shatter the ice into a confusion of immense blocks. Snow bridges similar to those in the Swiss glaciers are the only means of crossing these chasms, and lend a spice of danger to the whole examination. The region of the terminal moraines is quite unlike that of the Alps, a larger portion of the glacier itself being covered by loads of angular débris. The whole north face of the mountain is one great body of ice, interrupted by a few sharp lava ridges which project above its general level. The veins of blue ice, the planes of stratification, were distinctly