222 



NATURE 



[April 21, 1910 



between ii and 12 km* is 20 mm. at Manchester and 

 28 mm. at Pyrton Hill, which has a higher tempera- 

 ture at that height. Similar differences occur between 

 13 and 14 km., and between 5 and 6 km. 



Great difficulty is experienced in reconciling the 

 temperature observations with the observed and ex- 

 pected decrease in wind velocity in the advective region. 

 The obvious errors noted above may be partly re- 

 sponsible for the extraordinary velocity of 150 m.p.s., 

 found from the horizontal gradient of pressure at 

 16 km. But apart from errors of calculation, an error 

 of only 1° C. in the mean temperature of the air 

 column would produce an error of nearly 3 mm. in 

 the pressure at 16 km. It must also be remembered 

 that where convection is prevented the condition of 

 steady motion may never be reached, and the differ- 

 ences of pressure may be equalised by translation of 

 air across the isobars with moderate velocity. 



Dr. Shaw finds that if the lower surface of the 

 advective region is depressed owing to a disturbance 

 in the lower atmosphere, there will be an increase of 

 temperature of 9° C. per km. of 

 depression. Such a depression 

 would • presumably be propagated 

 with the same velocity as the dis- 

 turbance, but the obstacles to con- 

 vection in the advective region may 

 make the upper portion of the at- 

 mosphere act as a damping agent 

 by which the disturbance would be 

 annulled. 



The mean, maximum, and mini- 

 mum values of H^ and T^, the 

 height and temperature at which 

 the advective region begins, are 

 given in the table : — 



Mean He MeanTc He 



Manchester ii;6km. 219° Ajj^^^_ 15-2 km. 

 f vrton HiU 12 o ,, 217 ,,| -^ 



Dicham ... i2"2 ,, 221° „j .,- _.a _,,o 



C^* I Aim. 75,, 204 ,, 

 rinan ... 110 ,, 226 ,,/ / >> t >• 



The values are higher than the 

 mean values found by the present 

 writer and Harwood. The difference, 

 probably arises partly through the 

 method of fixing He, partly owing 

 to the exclusion of the 1909 results 

 from the present report. 



It is a pleasure to note that pres- 

 sure is expressed in megadynes per 

 cm.-, and temperature in degrees 

 C. above the absolute zero. The 

 report is full of interest to all en- 

 gaged in upper-air research, and 

 will be especiallv useful to those who 

 are contemplating the establishment of new experi 

 mental stations. E. Gold. 



watersheds of Asia. Here that is gashed by rather 

 short and steep transverse valleys, rltogether nine in 

 number, and attains an elevation often exceeding 20,000 

 feet above sea-level. On the southern side is another 

 mountain wall, not quite so lofty, though even its 

 lowest point is quite a thousand feet above the summit 

 of Mont Blanc. From its western part — rather more 

 than fifteen miles in extent — six tributary glaciers — 

 three of them large— descend to the Hispar, but its 

 eastern and upper portion — fully twenty-one miles in 

 length — is practically unbroken. A rather long and 

 flat snow saddle, 17,500 feet above sea-level, parts 

 the Hispar from the Biafo Glacier, which descends 

 towards the south-east, and the total length of the 

 former, from its termination near Hispar village, at a 

 height of about 11,000 feet above sea-level, is, accord- 

 ing to Dr. Workman's measurement, a little less than 

 thirty-seven miles, or a mile and a half greater than 

 that assigned to it by Drs. Calciati and Koncza. 



The pass over the Hispar and Biafo glaciers, 

 according to Lieut. -Colonel Godwin-Austen, who. 



Tc 

 241° A 



THE HISPAR GLACIER.' 



T^R. AND MRS. BULLOCK WORKMAN, the 

 -•--' well-known explorers of the higher Himalayas, 

 have read before the Royal Geographical Society a 

 most interesting account of the Hispar Glacier. This 

 is one of a group of four of the world's greatest 

 mountain-glaciers, which, together with two others 

 of them — the Biafo and the Chogo Lungma — and some 

 of their tributaries, have been explored from end to 

 end by these indomitable climbers. The Hispar 

 Glacier, one of the many feeders of the Indus, occupies 

 a long and nearly straight valley, running roughly 

 parallel with the crest of the Karakoram — one of the 



1 The Hispar Glacier. I. Its Tributaries and Mountains. By Fanny- 

 Bullock Workman. II. Prominent Features of its Structure. By 

 William Hunter Workman. (Geographical Journal, vol. xxxv., pp. 

 i°5~3'i February, 1910.) 



NO. 21 12, VOL. 83] 



Fig. I. — A g'acier-table of unusual size met with on the lowest third of the Biafo Glacier at an 

 altitude of about 3660 metres (12,000 feet). The rock-boulder was 5 metres (i6'4 feet) long, 

 the ice-pedestal 3'8 metres (i2'46 feel) high, and the height of the whole s"5 metres (18 feet). 

 A table with mu.h lower pedestal seen in distance at left. (From the Geographical Journal.) 



about half a century ago, explored these ice-clad fast- 

 nesses, was in former times occasionally used by 

 natives, especially marauders, but when Sir Martin 

 Conway traversed it in 1892* he found the traditions 

 were very vague. The only serious difficulties are 

 those due to the length of the journey at such a con- 

 siderable height above sea-level. These, however, did 

 not prevent Dr. and Mrs. Workman from spending 

 several weeks on their way over the pass from Hispar 

 village to Askole, and carefully studying this ice-clad 

 region. 



The Hispar Glacier has a low gradient — on the whole^ 

 about one in thirty — and its average width is a little" 

 less than two miles. It receives, as has been said, 

 six large tributaries from the northern side, and 

 three, also large, on the lower part of its southern 

 side. All, and especially the former, are laden with 

 debris to an unusual extent. The effect of this is 



1 See "Climbing and Exploration in the Karakoram-Himal.iyas,' 

 W. M. Co.iway, chapters xyi-.\i.x. (1894.) 



by 



