February i i, 1892] 



NA TURE 



339 



comes to an end, and no sooner is Z reached than the 

 compiler has to begin again at A. An additional decade 

 of serials, embracing the years 1864-73, containing about 

 99,000 titles, and filling two additional quarto volumes 

 (vols. vii. and viii.), was completed in January 1876, and 

 published by Her Majesty's Stationery Office in 1879. 

 But now the troubles of the Royal Society began. The 

 work of the next decade went steadily forward ; but as it 

 neared completion it was found, so rapidly does the bulk 

 of scientific serials increase, that, even keeping the Cata- 

 logue on the old lines, and making no considerable addi- 

 tion to the number of serials catalogued, ten years of 

 memoirs, which formerly filled two volumes, would now 

 fill three ; and, to add to the difficulty, the Treasury now 

 informed the Society that the " 'Catalogue of Scientific 

 Papers' would not be continued as a publication of the 

 Stationery Office." Parliament voted, however, a gift 

 towards the charges of publication, and this, supplemented 

 by the Royal Society's own funds, and the enterprise of 

 the Cambridge University Press, has enabled the decade 

 to be printed. 



So much for the past of the Catalogue ; and now a 

 word as to its future. The preface to the volume under 

 review states — what we have hinted at above— that the 

 list of works catalogued "by no means comprises the 

 whole of the scientific periodicals which at the present 

 day are being constantly published in various languages." 

 We believe it is no secret that the Committee of the 

 Royal Society who have the superintendence of this 

 great work have themselves printed and distributed 

 among the Councils of various scientific Societies, for 

 revision or additions, a list of no less than 540 addi- 

 tional serials, which may, might, should, or could be 

 catalogued, so far at least as regards the principal 

 memoirs which they contain ; and it is well known to 

 every scientific man how rapid is the multiplication of 

 scientific serials, and how increasingly difficult becomes 1 

 the task of keeping oneself acquainted with their con- 

 tents. We are glad to learn, from the preface already , 

 quoted, that " the President and Council have it in con- 

 templation to issue a supplementary volume, in which 

 will be catalogued all the most important papers that 

 have appeared from 1800 to 1883 in periodicals not 

 hitherto indexed." We wish them well through their 

 task, only venturing the gentle hint, " Bis dat qui cito 

 dat." Nothing is said in the preface about future decades, 

 but we sincerely trust that, notwithstanding the alarming 

 increase of periodicals and the unfortunate withdrawal 

 of Government aid, some means will be found for con- 

 tinuing the work : perhaps a hint might be taken from 

 the British Association Report which initiated the whole 

 undertaking, and by which it appears that America was 

 willing to help. 



One other matter needs to be mentioned — the im- 

 portant matter of a subject-index. Such an index, as we 

 have already stated, formed apart o*" the original scheme, | 

 and as certain correspondence in our own columns (vol. 

 xli. p. 341 ; xlii. p. 126) would seem to show, the Royal 

 Society, though they have not yet seen their way to under- 

 take it, still bear this great desideratum in mind. The 

 undertaking was perhaps nearer than at any other time to 

 being actually set on foot, when, in 1870, Dr. Carus visited 

 London, and actually spent some weeks at the Royal ' 

 NO. I 163, VOL. 45] 



Society's apartments in planning and making specimens 

 of such an Index Rerum. Unfortunately, the Franco- 

 Prussian War prevented the return of Dr. Carus to London 

 as had been arranged, and the work was never continued. 

 How difficult such an undertaking is, perhaps few fully 

 understand, requiring as it does, at the very threshold of 

 the work, a complete and perfect classification of all the 

 sciences, and involving, moreover, all kinds of difficult 

 questions and perilous cross-divisions. But, difficult as 

 it is, we trust that, to the great advantage of science, and 

 the true " promotion of natural knowledge," the Royal 

 Society may yet accomplish a work so greatly needed. 



X. 



THE ANEROID IN HYPSOMETRY. 

 How to Use the Aneroid Barot/ieter. By Edward 

 Whymper. (London : John Murray, 1891.) 



IN undertaking a somewhat laborious investigation of 

 the behaviour of the aneroid under great variations 

 of pressure, and in publishing the results in the little 

 pamphlet that bears the above title, Mr. Whymper has 

 rendered a service to travellers and geographers, which 

 they will acknowledge not the less cordially that it 

 brings with it the bitter reflection that very much of 

 their past work in determining mountain heights by 

 means of that convenient instrument, is probably seriously 

 in error. 



All who have had any experience in testing aneroids 

 in the usual way, viz. by subjecting them to gradually 

 reduced pressures under the air-pump, and comparing 

 their readings with the concomitant indications of the 

 manometer, are aware that the variations of the two 

 instruments with falling and then with increasing pres- 

 sure are by no means concordant ; but it will probably 

 be new to most that, when the aneroid is allowed to 

 remain for some weeks under the reduced pressure, its 

 indications continue falling, and to such an extent that 

 its final error in certain cases is five or six times as great 

 as when the exhaustion was first completed. Now this 

 is precisely the condition experienced by travellers on 

 high plateaux or great mountain tracts, where days or 

 perhaps weeks are passed at altitudes of many thousands 

 of feet above the sea-level. The instrument on which 

 they rely for their elevations has been undergoing a rapid 

 and not inconsiderable fall, which is merely an after-effect 

 of the ascent already accomplished and recorded ; and if, 

 after returning to low levels, some weeks elapse before they 

 again compare it with a mercurial standard, the whole of 

 this accumulated error will have disappeared, and it 

 may even have been replaced by an error in excess of 

 the original reading. The Kew certificate of the 

 aneroid's performance will afford no clue to its detection, 

 and the elevations they have determined during their 

 sojourn at high levels will be uniformly in excess of the 

 truth. 



It was an experience of this kind on the high plateau 

 of Ecuador that first drew Mr. Whymper's attention to this 

 peculiarity in the behaviour of the aneroid. But he was 

 not working in the dark. Together with a battery of 

 aneroids he carried with him a mercurial barometer, and 

 by dint of frequent comparison with this standard, he was 



