Sei'Tember 13, 1894] 



NA TURE 



4S9 



numbered, as you see, from zero to nineteen. E.ery one of 

 these resulting monthly positions of the pole indicited by the 

 centres of the small circles is thus the mean result of about 300 

 single determinations. 



The accompanying figure is drawn on a scale of two milli- 

 metres to one-hundredth of a second of arc, and the maximum 

 amplitude of the curve is nearly 50-hundredths, or half a second. 

 The amplitude of these movements of the pole on the surface 

 of the earth is between 40 and 50 feet. 



Vou seethe general character of the movement quite in accord- 

 ance with what has been mentioned concerning its complicated 

 and somewhat spiral character. The sense of the motion is turn- 

 ing from west to east. The velocity is apparently very variable, 

 and it seems as if we now approach an epoch in which the 

 simplitude considerably diminishes. It is also evident that such 



06 



Fig. I. — Movement of the North Pole of ihe rotational axis of the earth 

 Derived from observations made at Bethlehem, Strassburg, and Kasan : — 



=1893 Oct 20 



1 = ,, Nov, I. 

 z = ,. Dec. 1. 

 3 = '893 Jan- >■ 



13 ^ 1893 Nov. I. 

 Z4 ^ .. Dec. 1. 

 15 = 1894 Jan. I. 



19 = 1S94 Mar. 30, 



a character of movement can very easily produce slow progres- 

 sive motions, and also from this reason the whole phenomenon 

 wants to be watched incessantly and very carefully. 



The astronomers and geodetists who are now associated 

 in the International Geodetic Union, have invited the 

 geologists to associate with them in this common research. 

 .■5uch an international organisation will be also useful and 

 almost indispensable for a great part of the work of astronomical 

 observatories. 



It is to be hoped that Great Britain will now participate 

 in this international union, embracing all other civilised 

 nations. Such organisations, with their clear and reasonably 

 limited aims, involve not only real economies and refinements 

 of mental work, comliined with diminutions of material exp;nses, 

 but it is hoped that they will also have a great importance as 

 slowly growing foundations of hum.in and terrestrial solidirity. 



SCIEXCE IN THE MACAZIXES. 



ATR. HIR.\M S. M.\XIM gives, in the Nationa!, a brief 

 ■^ description of his experiments on flying by means of aero- 



planes. His flying machine, when finished and loaded with its water, 

 its fuel, and three men, weighed very nearly 8000 lb , and the 

 actual horsepower developed on the screws was 363 horse- 

 power, with a screw-thrust of rather more than 2000 lb. The 

 total width of the machine was over 200 feet. It was found 

 that upon running the machine at thirty miles an hour very little 

 load remained on the lower track, and at thirty-six miles an 

 hour the whole machine was completely lifted. 



The Fortnightly is remarkable this month for two critical 

 articles by Prof. Karl Pearson and .Mrs. Lynn Linton, respec- 

 tively. Prof. Pearson assails Lord Salisbury's address to the 

 British Association, and moans over the fact that Lord Kelvin 

 courteously said that throughout it " there was the spirit of the 

 student, the spirit of the man of science. " Here is his opinion on 

 it: "We find nothing in it which shows the spirit either of 

 student or of man of science ; it teems with fallacious conclu- 

 sions, and whatever may have been intended by the author, it 

 can only serve as an appeal to that gallery which is occupied 

 by the reconstructed theological party." Mrs. Lynn Linton 

 outpours the vials of her wrath upon Prof. Henry Drummond 

 and his "Ascent of Man." " He brings his subject," says she, 

 " which only the educated can rightly understand, down to the 

 level of the ignorant. He strips science of her divinity, and 

 sends her out as a cottage-maid, or rather as a young priest, of 

 whom no one need be afraid. But he lets slip truth in this en- 

 deavour to extract milk for babes out of the meat for men ; and 

 his rendering of synthethic philosophy is both inadequate and 

 shallosv. Whatever is true is borrowed ; whatever is false, 

 strained, and inconclusive, is his own. His sin is the sin of 

 plagiarism, with the additional offence of distortion in the 

 lifting." Surely a writer never received a more terrible flagella- 

 tion than this. 



Brief descriptions will suffice for other articles of more or less 

 scientific interest in the magazines received by us. Sir Robert 

 Ball contributes to Good IVordi a paper on Galileo. The 

 Century contains a continuation of Messrs. Allen and Sachtle- 

 ben's account of their journey across Asia on bicycles ; and a 

 fine picture of an aurora, observed and sketched at Godthair on 

 September 3, 1892, by Mr. F. W. .Stokes, one of the members 

 of the Peary Relief Expedition. Dr. Carl Lumholtz describes 

 in Scribmr the life and costumes of the Tarahumaris, the 

 inhabitants of the Sierra Madre. In Chamber^ s Journal we 

 find a diversity of instructive articles. Among Ihe subjects 

 scientifically treated are " British Ring-Snakes," " Dj-namite," 

 "Sweet Lavender,' and "Sources of Power in Nature." 

 Lovers of nature will find pleasure in an article entitled " In a 

 Rock Pool," contributed by the Rev. Theodore Wood to the 

 Sunday Magazine, and geographers will be interested in a de- 

 scription ol the inhabitants of the Andaman Islands. Under 

 the title "Spirit and Matter," Emma Marie Caillard philo- 

 sophises, in the Ct>nlemporary, on such psychical subjects as w-ere 

 touched upon by Prof. Oliver Lodge in his British Association 

 address in 1891. 



SCIENTIFIC SERIALS. 



Bulletin dc P Academie Royale de Bel^ique, No. 7. — Com- 

 parative study of the isothermals observed by M. Amagat and 

 the isothermals calculated from M. Van der Waals's formula, 

 by MM. P. de Heen and F. V. Dwelshauvers-Dery. .-V com- 

 parison of the theoretical and experimental isothermals shows 

 that the molecules which constitute carbonic anhydride expand 

 regularly as the temperature increases. The coefficient of mean 

 molecular expansion, for temperatures between 30^ and 258', is 

 sensibly equal to 0001, a number which closely approaches the 

 coefficient of expansion of liquids in general. To this intra- 

 molecular dilatation corresponds the internal latent heat of 

 dissociation, made evident by the variability of the specific heat 

 of carbonic anhydride in the gaseous stale. Since Van der 

 Waals's equation furnishes fairly accurate values for the part o 

 the isothermals situated to the right of the minimum, one might 

 feel tempted to introduce another constant and to force the 

 curve to pass through a supplementary point conveniently 

 chosen to the left of that minimum. "I'his would give much 

 more satisfactory results, but they would have nj value with 



NO. i::9S, VOL. 50] 



