May 27, 1898.] 



SCIENCE. 



745 



issued a month or two ago, have been 

 largely responded to, and many foreigners from 

 the Continent are expected, as well as a strong 

 contingent of scientific men from the Dominion. 

 During the week the International Conference 

 on Terrestrial Magnetism and Atmospheric 

 Electricity will hold its meetings in association 

 with Section A (Mathematics and Physical Sci- 

 ence). There will be no Section I (Physiology), 

 as the international meeting will be held at 

 Cambridge only a short time previous. 



LIQUID HYDROGEN. 



According to the London Times Professor 

 Dewar liquefied hydrogen on May 10th at the 

 Eoyal Institution and exhibited the liquid to 

 Lord Rayleigh, who was fortunate enough to be 

 on the premises at the time. Hydrogen has 

 been liquefied before — in theory, but Professor 

 Dewar has actually produced the liquefied gas 

 to the amount of half a wine-glassful in five 

 minutes, by a process which would equally have 

 produced a pailful had the requisite supply of 

 pure hydrogen been forthcoming. This is a 

 unique and unprecedented feat. Liquid hydro- 

 gen in quantity is not only of enormous scien- 

 tific interest in itself, but is also of immense 

 importance as placing a new and potent instru- 

 ment in the hands of investigators who have 

 hitherto found their progress barred by its ab- 

 sence. The boiling point of the liquid may be 

 placed at from thirty to thirty-five degrees of 

 absolute temperature, or, in other words, at 

 about 240 degrees below zero on the Centigrade 

 scale. Some conception of the degree of cold 

 attained may be gathered from the fact that a 

 tube closed at the lower end, when emersed in 

 the liquid, was almost instantaneously filled 

 with solid air. It may be observed, as a matter 

 of scientific interest, that the density of the 

 liquid far exceeds that arrived at by calculation. 

 There is reason to believe that it will be found 

 to be about 0. 6, water being unity. This result 

 would agree very closely with the density of 

 hydrogen when occluded by palladium, as es- 

 tablished by Professor Dewar 25 years ago. 

 Helium is a rare gas which has hitherto resisted 

 all attempts to effect its liquefaction. It is 

 stored in considerable'quantity at the Royal In- 

 stitution, and was also liquefied on Tuesday by 



the use of the liquid hydrogen. Its boiling 

 point appears to lie not very far from that of 

 hydrogen itself. Liquid hydrogen will never 

 be as cheap as liquid air, because nature does 

 not supply the gas in equal abundance. But 

 nothing except the cost now stands in the way 

 of producing liquid hydrogen in any quantity 

 that science may require, whether for investi- 

 gation of its own properties or for the prosecu- 

 tion of various lines of research into the con- 

 stitution of matter in general. 



GENERAL. 



The Council of the Koyal Geographical So- 

 ciety have awarded one of the two Eoyal medals 

 to Dr. Sven Hedin for his work in Central Asia, 

 and the other to Lieutenant B. A. Peary, Uni- 

 ted States Navy, for his explorations in North- 

 ern Greenland. The Council have also made 

 the following awards : The Slurchison grant 

 to Mr. H. Warington Smyth for his several 

 journeys in Siam ; the Back grant to Mr. George 

 P. Tate for his survey work in Afghanistan, 

 Beluchistan, especially Makran, Aden and on 

 the Indus ; the Gill memorial to Mr. Edmund 

 J. Garwood for his geographical work in Spits- 

 bergen during two seasons, in company with 

 Sir Martin Conway ; the Cuthbert Peek grant 

 to Mr. Poulett Weatherley for his exploration 

 of the region between Lakes Mweru and Bang- 

 weolo. The following foreign geographers and 

 travellers have been elected honorary corre- 

 sponding members : Don Marcos Jimenes de la 

 Espada, Don Francisco Moreno, Buenos Ayres ; 

 Marquis of Rio Branco, Brazil ; Dr. Thoroddsen, 

 of Iceland; Professor Eatzel, of Leipzig. 



Portraits of Mr. Frederick Fraley and of 

 Professor J. Peter Lesley were presented to the 

 American Philosophical Society, Philadelphia, 

 on May 20th. Mr. Fraley, who has long been 

 President of the Society, and is about to cele- 

 brate his 94th birthday, was present. Professor 

 A. H. Smith, of the Central High School, stated 

 that the Society now possessed portraits of all 

 its Presidents, beginning with Franklin. In ac- 

 cepting the portrait of Professor Lesley, Mr. W. 

 A. Ingram dwelt upon his services to geology 

 and geodesy. Professor Lesley has been for 

 many years one of the Vice-Presidents of the So- 

 ciety and had previously filled the offices of Li- 



