860 



THE POPULAR SCIENCE MONTHLY, 



proachable only through valleys occupied 

 by large streams. The first attack was 

 made upon Dunnagiri, which is 23,184 feet 

 high. In order to reach it they had to 

 climb over two peaks 17,000 and 18,000 

 feet high, and then, after a five days' march, 

 they camped on a glacier at the height of 

 18,400 feet. On the sixth day they reached 

 a height of 22,500 feet, when, a snow-storm 

 coming on, they were compelled to retreat, 

 after they had come in sight of their goal. 

 Mr. Graham observes that the peaks of the 

 Himalayas, as a rule, are considerably steep- 

 er than those of the Alps ; and he is con- 

 vinced that breathing is no more difficult at 

 the height he reached than at 10,000 feet 

 lower down. The party also ascended the 

 Kang La, 20,300 or 20,800 feet high, and 

 a new mountain, 23,326 feet high, which 

 was called Mount Monal, from the number 

 of birds of that name seen upon its slopes. 



Volcanic and Cosmic Dnsts in Submarine 

 Deposits. — Messrs. John Murray and A. Re- 

 nard have taken advantage of the phenom- 

 ena attending the eruption of Krakatoa last 

 year for the extension of their studies in the 

 accumulation of volcanic debris and cosmic 

 dust in deep-sea deposits. Mr. Murray had 

 already shown, before the Royal Society of 

 Edinburgh, in ISYG, that volcanic. materials 

 play the most important part in the forma- 

 tion of these deposits, and how they may 

 have been furnished by the decomposition 

 of pumice and the settling of incoherent 

 volcanic ejections. Rounded fragments of 

 pumice are collected on the surface of the 

 sea in regions far from coasts, and at cer- 

 tain points on the bottom of the ocean the 

 greater part of the deposit is composed of 

 vitreous splinters derived from the tritura- 

 tion of such stones. The eruption of Kra- 

 katoa in a few hours filled the Bay of Lam- 

 pong with about 150,000,000 cubic metres 

 of ejected matter. Floating fragments from 

 this source were collected on the surface of 

 the water with their angles rounded off, and 

 showing, as the only asperities upon their 

 surface, crystals and fragments of crystals 

 projecting beyond the mass of vitreous mat- 

 ter. The crystalline fragments and volcanic 

 minerals can not be identified with certainty 

 when reduced to their finest state, as in the 

 deep-sea deposits ; for in that condition they 



lose all their characteristics of form and op- 

 tical properties. The case is different with 

 the vitreous particles derived from the pum- 

 ice, or included in the volcanic ash, whose 

 characters remain constant to the extreme 

 limits of pulverization. The results of the 

 study of the micro-structure of the vitreous 

 particles from Krakatoa, which are described 

 in full by the authors, can be applied with 

 most perfect exactitude to the volcanic dusts, 

 which have been determined as such, in the 

 deep-sea deposits. The latter have, how- 

 ever, only partly been derived from the pul- 

 verized ejections of a volcano, but more from 

 the trituration of floating pumice ; but it is 

 hardly possible to trace the differences be- 

 tween the two. The minerals that can be 

 determined in the ashes of Krakatoa are the 

 same as are almost always found in the de- 

 posits along with the splinters of glass. It 

 is not to be expected that the volcanic dusts 

 found in all the deep-sea deposits shall be 

 uniformly identical. In the first place, they 

 may originate from magmas of varying char- 

 acters, according as they come from volca- 

 noes in different parts of the world. The 

 matter also goes through a sifting process as 

 it is carried through the air and in settling 

 in the water. The vitreous particles, being 

 lighter, are carried farthest from the vol- 

 canic center, and are longest in reaching the 

 bottom. The fact has been illustrated in 

 the case of Krakatoa that, in proportion as 

 the ashes are collected at a greater distance 

 from the volcano, they are less rich in min- 

 erals, and the quantity of vitreous matter 

 predominates ; a submarine tufa-deposit in 

 the center of the South Pacific, in which the 

 particles are graduated from the bottom up, 

 illustrates the difference in the facility of 

 settling. The evidence that has been ad- 

 duced in favor of the hypothesis of a circu- 

 lation in the atmosphere and a settling upon 

 the earth of cosmic dusts is doubted by some, 

 who have suggested various possibilities of 

 an earthly origin for the particles described 

 as cosmic. According to our authors, how- 

 ever, many of the doubts are at once re- 

 moved by a statement of the circumstances 

 under which cosmic spherules are formed in 

 deep-sea deposits, and when the association 

 of the metallic spherules with the most char- 

 acteristic bodies of undoubted meteorites is 

 shown. Cosmic particles are found in most 



