464 



N^ TURE 



[March 19, 1908 



these be confirmed, is unusually slow, a maximum of 

 60 feet a year. 



The Wenkchemna receives the name of a Piedmont 

 tjlacier, rather on the Bottom's dream principle, 

 lor, though formed by the lateral union of several 

 short ice-streams (called " commensal " because they 

 are fed from different sources), they come to an end 

 high up in a ntountain valley. The Yoho glacier, on 

 the west side of the divide, is split into two by a 

 rocky rib at its lower end, and is unusually free from 

 surface debris. The lllecillewaet glacier, best known 

 (if .those in the Selkirks, with its steep cascade of 

 shattered seracs, forms an imposing feature in the 

 landscape, but, as a comparison of the accompanying 

 figures plainly shows, retreated considerably between 

 1888 and 1905. The Asulkan glacier is the smallest 

 ;md most southern of the five, but is nevertheless a 

 fine object. 



Lakets, moraines, and other "leavings" of the ice 

 show that all these glaciers have retreated in com- 

 paratively recent times, but more facts must be 

 gathered before the periodicity of their movements 

 can be ascertained. It is, however, as Dr. Sherzer 

 points out, not unlikely to agree with the approximate 

 tliirty-five and a half years already inferred for other 

 districts, and we may notice in passing that in these 

 mountains the " Chinook " wind is a substitute for 

 the Alpine " Fohn." He claims for glaciers a certain 

 amount of erosive action — the scooping out of small 

 lake-basins in favourable circumstajices, and the 

 conversion of valleys in their lower parts from 

 V-shaped into U-shaped. The latter may be; but we 

 cannot help remarking that in the Alps, where the 

 ice at equal distances can hardly have been less in 

 quantity, it seems to have been singularly incapable 

 of effacing any pre-existent feature of importance. 

 Dr. Sherzer also claims that ice can exercise a pluck- 

 ing action, but apparently only when passing over a 

 much-jointed quartzite. Obviously, this would be the 

 worst possible material for making roches moutonnies, 

 but even here we should like a little more proof that 

 the glacier has mastered the " art of pluck." 



The so-called " bear den " moraines — piles of coarse 

 broken rock without the usual infilling of fine 

 material — seem to be one of the more exceptional 

 features of this region. Dr. Sherzer regards them 

 as records of " landslides " upon the ice from the 

 higher peaks. That would explain their structure, 

 but we doubt whether an earthquake is needed to 

 start a "' berg fall." Not to mention earlier instances, 

 those near Elm in the Sernfthal and from Turtle 

 mountain in Alberta occurred without any seismic 

 disturbance. The prismatic structure in " ice dykes " 

 is also remarkable, and recalls that exhibited in 

 glacieres and pond-ice — a subject once much discussed, 

 among other places, in the first and second volumes 

 of Nature. On the whole, though sometimes, 

 perhaps, a little too diffuse in describing the well- 

 known, Dr. Sherzer has made a valuable and remark- 

 ably well-illustrated contribution to the literature of 

 glaciers. 



T. G. BONNEV. 



THE FORTHCOMING MATHEMATICAL 

 CONGRESS AT ROME. 

 A S was announced in Nature for February 6, the 

 •^*- fourth International Congress of Mathematicians 

 will be held at Rome in the week before Easter. The 

 congress meets once every four years, the previous 

 places of meeting being Zurich, Paris, and Heidel- 

 berg. On this occasion the order of proceedings will 

 be as follows : — 



. Sunday, April 5 ; Reception at the Aula Magna by 

 NO. 2003. VOL. 77] 



tlie principal of the L'niversity, at g.3op.m. Monday, 

 .April 6 : Inaugural meeting at 10 a.m. at the Capitol, 

 at which Prof. Volterra will read a discourse on 

 Italian mathematics in the last half of the nineteenth 

 century. .At 3 p.m. a general meeting will be held 

 at the Reale .Vccadeniia dei Lincei for the election of a 

 piesident and for the award of the Guccia medal, fol- 

 lowed by two lectures. From Tuesday, April 7, to 

 .Saturday, .\pril 11, the congress will meet in four 

 sections every morning at 9 a.m., the subjects of the 

 sections being (i) arithmetic, algebra, and analysis; 

 (2) geometry ; (3) applied mathematics ; (4) 

 philosophy, history, and teaching of mathematics. In 

 the section of applied mathematics the subject of 

 actuarial mathematics will be introduced by Prof. 

 Toja for the first time at these congresses. On each 

 of the afternoons of .\pril 7, 8, and 10, two lectures 

 will be given, commencing at 3.30 p.m. Thursday, 

 .'\pril 9 : Visit to the Palatine by invitation of tlie 

 Minister of Public Instruction, at 3 p.m. Saturday, 

 April II : Concluding general meeting; arrangements 

 for date and place of next congress. Ninth and tenth 

 lectures. Sunday, April 12 : Visit to Hadrian's villa 

 and lunch at Tivoli. 



In addition, a reception will be given by the muni- 

 cipality in the museum of the Capitol on some even- 

 ing during the week. 



The lectures arranged are as follows : — Darboux 

 (infinitesimal geometry), Forsyth (partial differential 

 equations of the second order), Hilbert (method of 

 infinite number of independent variables), Klein (the 

 " Mathematical Encyclopedia "), Lorentz (partition of 

 energy between matter and ether), Mittag-Leffler 

 (representation of functions of a complex variable), 

 Newcomb (lunar theory), Picard (analysis and mathe- 

 matical physics), Poincare (subject to be announced), 

 Veronese (non-archimedean geometry). 



From March 25 to May 5 the Italian State railways 

 will issue tickets at reduced fares to those attending 

 the congress from the frontier stations, as well as for 

 ten separate journeys in any part of Italv. In addi- 

 tion, all members are granted free admission to the 

 principal museums and galleries in Rome between 

 April I and April 12. The subscription is fixed at 

 25 lire (i/.) for members, or 15 lire for those belong- 

 ing to the family of a member who desire to enjoy 

 the same privileges ; but to obtain railway vouchers 

 for the outward journey subscriptions have to be 

 received before March 25 by the treasurer. Prof. 

 Vincenzo Reina, 5 Piazza S. Pietro in Vincoli, Rome. 



From the point of view of the English mathe- 

 matician, the time fixed for the congress this year 

 is somewhat inconvenient, as those who attend will 

 doubtless wish to see something of Rome at the 

 same time, and not only are our Easter vacations, as 

 a rule, very short, but in many cases they do not even 

 cover the period fixed for the congress. These 

 difficulties could have been obviated by holding the 

 congress at its more usual time in the summer vaca- 

 tion, and had this been done no inconvenience would 

 probably have been experienced from the heat, though 

 some people might have been deterred from attending 

 owing to fears in this respect. In view of the fact 

 that only seven Englishmen attended the last con- 

 gress, it is important that everyone who can attend 

 should do so this time, even if this involves an ex- 

 tension of their holiday beyond the ordinary limits of 

 the school or college vacation. It would be a great 

 pity if anyone were debarred from attending 

 these gatherings merely for the sake of a week's 

 teaching to a class of elementary pupils, and it is to- 

 be hoped that the governing bodies of our schools 

 and colleges will not allow such small obstacles to 

 stand in the way of their mathematical representa- 



