124 



NATURE 



[November 24, 19 10 



get a simple sequence of events following one another in 

 due order, and with intervals of varying length, and these 

 we are tempted to look upon without allowing for the 

 perspective. The more minutely the events that have 

 taken place since man appeared in Europe are examined, 

 the more profound is the impression of the vastness of 

 his antiquity and the futility of any attempt to compute 

 it in terms of vears. 



THE DUKE OF THE ABRUZZPS EXPEDITION 

 TO THE KARAKORAM HIM ALA YAS} 



T^HE expedition undertaken in the summer of iqot) bv 

 ■*• the Duke of the Abruzzi to the head of the Baltoro 

 and the Godwin Austen glaciers in the Karakoram was 

 essentially a mountaineering expedition. On the way out 

 the longer summer route was followed across the Punjab 

 Himalayas over the Zoji-La (11,230 feet), and down the 

 valleys of the Dras and of the Indus, to Skardu, the 

 capital of Baltistan. Here the route quits the Indus to 

 ascend the Shigar and Braldoh valleys up to Askoley, the 

 last inhabited spot, after which the glacier region is 

 entered. While traversing Baltistan the expedition had 

 the opportunity of seeing much of the Balti population 

 and of photographing several groups of them. There can 

 be no doubt that the great majority of the Baltis belong 

 to the Aryan stock, and not to the Mongol-Thibetan, as 

 has been stated by all English writers on the subject. 

 The distinguished Hungarian anthropologist Uifalvv had 

 already demonstrated their close affinity to the Dards bv 

 comparative anthropometrical measurements. 



A few miles above Askoley the Braldoh valley is inter- 

 sected by the snout of the Biafo glacier. This glacier has 

 undergone considerable variations in a recent period. In 

 i86r, when Colonel Godwin Austen first visited it, it was 

 wedged against the opposite or left bank of the Braldoh 

 valley in such a way that the emissary stream of the 

 Baltoro flowed through a tunnel underneath it. In 1892 

 Sir Martin Conway noted that it had withdrawn to such 

 an extent as to leave free more than half of the valley, 

 upon which it had deposited a deep layer of moraine. 

 Since then the movement has again been forward, and in 

 1909 there were only from 200 to 300 yards between the 

 snout and the rocks of the left wall of the valley. 



On May 18 the expedition climbed up on to the Baltoro 

 glacier. The snout of this glacier still corresponds abso- 

 lutely with the description of it given by Conway in 1892. 

 It may possibly be stationary, but certainly shows no sign 

 of shrinking. All the tributary glaciers appear to be on 

 the increase, and stretch out for a long distance on the 

 top of the Baltoro, the surface of which they strew with 

 broken seracs. Here angular measurements were taken, 

 which were repeated two months later on the return 

 journey, and established that the rate of motion of the 

 centre of the glacier is on the average 5J feet a day 

 during the months of June and July. 



Later on the rate of the upper Godwin Austen glacier 

 was observed. In the course of seven years the move- 

 ment gave an average daily rate of barely 2 feet — con- 

 siderably less than that of the lower Baltoro, although 

 the grade is much steeper. 



Near Rdokass were noticed on the glacier the strange 

 pyramids of pure white ice which were first observed by 

 Colonel Godwin Austen in 1861. At this point they appear 

 as i.solated cones, from jo to 20 feet high ; next as sharp 

 pinnacles ; and at last, higher up, as huge blocks from 

 100 to 150 feet in height, shaped like irregular prisms, and 

 getting- nearer and nearer together until they seem to be 

 arranged in longitudinal rows. 



The Karakoram range does not seem likely to offer an 

 opportunity of solving the problem of the highest altitude 

 attainable by man. The greater portion of the chain 

 looks absolutely inaccessible. The difficulties of the ice 

 and the rock are in most places so great that not even 

 European alpine porters could carry up a load without 

 the help of fixed ropes. This prevents the establishment 

 of. high camps, and was the obstacle which frustrated the 

 Duke's one attempt to ascend K, by the rocky south- 

 eastern arete. 



1 Abstract of a lecture delivered before the Royal Geographical Society 

 on November 21 by Dr. F. De Filippi. 



NO. 2143, VOL. 85] 



The exploration of the Godwin Austen glacier was com- 

 pleted by the end of June, and the Duke now decided to 

 attempt the Bride peak (Karakoram No. 8 of T.S. of 

 India, 25,110 feet), as being the highest and offering the 

 additional advantage of having been trigonometrically 

 fi.xed by the T.S. of India. 



The Duke succeeded in establishing a camp on the 

 Chogolisa saddle (20,778 feet), between the Golden Throne 

 and the Bride peak. F"rom this camp, an altitude of 

 24,600 feet, a little more than 500 feet below the summit, 

 was reached on July 18. 



The calculation of the altitude reached is based upon a 

 barometric reading (12/j inches) referred to those taken 

 on the same day at Skardu, Lch, Srinagar, and Gilgit. 



The result of the survey is a map which comprises the 

 upper basin of the Baltoro glacier, the whole of the 

 Godwin Austen glacier, with its tributaries, which encircle 

 three-fourths of K^, and the mountain chains which enclose 

 them. A number of new altitudes are given on the map. 

 Of these, the most important is the one which assigns to 

 the Broad peak an altitude of 27,133 feet. This altitude, 

 added to that of Teram Kangri (27,610 feet), at the head 

 of the Siachen glacier, brings up to seven the number of 

 peaks now known to be above 27,000 feet. The other five 

 are Mount Everest, K,, the two peaks of Kanchenjunga, 

 and Makalu. 



The experience of this journey agrees with that of the 

 Ruwenzori expedition in showing that the aneroid baro- 

 meter is too delicate an instrument for mountain expedi- 

 tions, and must be regarded as quite untrustworthy. 



There is every reason to believe that the high regions of 

 the Karakoram have a climate of their own which differs 

 from that of the lower valleys, notwithstanding the short- 

 ness of distance as the crow flies. This experience con- 

 firms the observation recorded by previous explorers as to 

 the absence of all electric phenomena in the atmosphere. 



The expedition has recorded that the great chain of 

 mountains comprising the Broad peak, the four Gasher- 

 brums, and the Golden Throne, is composed of limestone 

 and sedimentary rocks, whereas the opposite ranges, com- 

 prising the Staircase peak, K^, and Bride peak, consist 

 of crystalline rocks. 



AHREN'S BI LIQUID PRISM. 



TV/J R. C. D. AHRENS, the veteran prism-cutter, has 

 lately devised a new type of liquid prism, which 

 seems to have some advantages in optical work, both for 

 direct-vision and for ordinary patterns of spectroscope. It 

 is more than fifteen years since Wernicke proposed to 

 employ in a direct-vision combination the highly dispersive 

 liquid cinnamic ether. He found amongst modern sorts of 

 optical glass one kind, a baryta crown, having the same 

 mean refractive index, namely, 1-56, but having only 

 about one-fifth as much relative dispersion. He was there- 

 fore able to make a flat-ended direct-vision prism by 

 enclosing a glass prism of from 120° to 130° of refracting 

 angle in a cell filled with the cinnamic ether, which thus 

 constituted a triple combination, the glass prism being 

 flanked by two reversed prisms of the ether. Several 

 varieties of Wernicke's prism came into favour; but it had 

 the drawback that cinnamic ether- is expensive, and for 

 some reason becomes cloudy after standing for a year or 

 two in the containing cell. 



More recently another highly dispersive organic liquid, 

 also named by Wernicke, has found favour, viz. methyl 

 salicylate. This substance has a mean refractive index of 

 1-5319, and its constringency (the reciprocal of its relative 

 dispersion) is 24-7, as against ii-o for cinnamic ether. 

 Mr. F. Cheshire and others have used methyl salicylate 

 with great success, in combi^nation with reversed glass 

 prisms, in apparatus that may be regarded as an improve- 

 m.ent upon the prism of Wernicke. Methyl salicylate is, 

 however, much cheaper than cinnamic ether, and does not 

 become cloudy with lapse of time. 



Mr. .Ahrens has now produced a new type, the biliquid 

 prism. It consists of a glass container divided by oblique 

 partitions of thin plate glass into three triangular cells, 

 one of which is filled with methyl salicylate, the other two 

 with another liquid having a small dispersion relatively ta 



