354 



NATURE 



[March 2, 1876 



questions may be called " very easy," yet there are others 

 quite sufficiently difficult for the ordinary public school- 

 boy, who has a great many other things to work at 

 besides natural science. 



A boy must have read his chemistry thoughtfully, to 

 say the least, who could answer the whole of Question i 

 thoroughly. In Question 2 there is ample opportunity 

 for showing a deeper knowledge than could be obtained 

 by skimming over some " outlines of chemistry." So 

 again the explanation and illustration of the peculiar 

 oxidising and reducing properties of nitrites, in Question 

 4, and the description of the preparation and properties 

 of the different bodies enumerated in Question 8, could, I 

 maintain, only be given satisfactorily by boys who had 

 acquired something more than a mere " modicum " of 

 chemical knowledge. 



It must also be borne in mind that in order to pass 

 the Chemical Division of Group IV., a boy must take 

 in, in addition to the chemistry of the metallic and non- 

 metallic elements and practical analysis, either heat or 

 magnetism and electricity. 



Now although there may be reasons for combining 

 together heat and chemistry, so long as it is understood 

 that only the more elementary parts of heat will be 

 required, yet it is certainly unreasonable to add on as 

 an extra such a very comprehensive subject as that of 

 magnetism and electricity, frictional and Voltaic, including 

 electro-magnetism. 



Surely, to say the least, electrical science is quite as 

 worthy of an independent existence as botany or geology, 

 and I much doubt whether many would hesitate in ad- 

 mitting it to be much harder than either. 



My own opinion is in favour of Mr. Wilson's sugges- 

 tion — to divide Group IV. into Pass subjects and 

 Honour subjects, requiring only an elementary knowledge 

 of theoretical chemistry, and perhaps the simpler parts of 

 heat for the one, while practical analysis with higher 

 knowledge of heat, or electricity and magnetism, might 

 be required from those who aimed at taking honours in 

 science. 



It is perhaps due to the school to say that we can 

 hardly be supposed to be frightened at the prospect of 

 these examinations. Last July three in the Sixth took in 

 chemistry as a certificate subject : all passed and two 

 obtained " distinction " — three being the total number 

 who obtained such distinction out of the twenty-eight 

 candidates who presented themselves for examination in 

 this subject. T. N. Hutchinson 



Rugby 



In my letter last week, p. 329, I said that the papers 

 set in science in the certificate examination last year were 

 very easy. This was a shp. I was absent from England 

 when they were set, and had never seen them. I had in 

 my mind the papers of the year before. 



The papers of last year were quite hard enough. It 

 must be remembered that very many schools give only 

 two lessons a week to science. James M. Wilson 



ANNIVERSARY ADDRESS OF THE PRE- 

 SIDENT OF THE ROYAL GEOLOGICAL 

 SOCIETY, JOHN EVANS, F.R.S. 



■jV/T R. EVANS began by referring to the immense advances in 

 geological science since 1825, when the Society received 

 its charter, and pointed out that although there now existed a 

 considerable body of professional or trained geologists, yet 

 amateurs need not be discouraged from taking up the science 

 which now embraces so Avide a field that there is ample room for 

 both. He then referred to the prosperity of the Society, to its 

 pubhcation, its medals, and other means for fostering the 

 science, ana to its valuable museum, an "interesting notice of 

 which," he intimated, "appeared in Nature, vol. xiii. p. 227." 

 Mr. Evans then spoke of the present prospects of the science, 

 of the bearing which recent discoveries in other branches of 



knowledge has upon it, and of the direction in which future 

 discoveries are likely to be made. In this connection he referred 

 to the recent researches in solar physics by means of spectrum 

 analysis and solar photography, as having a close and intimate 

 bearing on the early history of the earth, and which was 

 discussed by Prof. Prestwich in his ioaugural lecture at 

 Oxford (Nature, vol. xi. p. 290). He spoke also of the 

 importance of spectrum analysis to the metallurgist, referrinqt to 

 the researches of Mr. W. C. Roberts in quantitative analyses of 

 gold-copper alloys. Mr. Evans then spoke at soms length of 

 the important results already attained by the Challenger Expedi- 

 tion as to the nature of the sea-bottom. In speaking of the 

 Arctic Expedition, from which geology hopes to gain much, he 

 referred to the powerful evidence which exists in the fossil flora 

 of Greenland and Spitzbergen, of the prevalence in the Arctic 

 regions at one period of a distinctly warm climate. 



Mr. Evans then went on to say : — The three points which it 

 appears to me are most important to bear in mind with regard to 

 the Arctic flora are : — l, That for vegetation such as has been 

 described, there must, according to all analogy, have been a 

 greater aggregate amount of summer heat supplied than is now 

 due to such high latitudes ; 2, that there must have been a far 

 less degree of winter cold than is in any way compatible with the 

 position on the globe ; and 3, that in all probability the amount 

 and distribution of light which at present prevail within the 

 Arctic circle are not such as would suffice for the life of the 

 trees. 



Should the present Arctic expedition succeed in finding traces 

 of what must be regarded as a temperate, if not indeed a sub- 

 tropical fossil flora, like that of Greenland, and Spitzbergen, 

 extending to latitudes still nearer the pole, it does appear to me 

 that geologists will be compelled to accept as a fact that the 

 position of the axis of rotation of our planet has not been 

 permanent ; and they will have to call upon astronomers to find 

 some means of admitting what they now regard as impossible. 



An astronomer and mathematician of no mean ability, the late 

 Sir John W. Lubbock, in a paper communicated to this Society 

 in 1848, has speculated upon this subject, which was in con- 

 sequence discussed by the late Sir Henry Delabeche in his 

 Presidential Address in 1849. 



Sir John Lubbock remarked that the dictum of Laplace as to 

 the impossibility of accounting for the changes which have taken 

 place on the surface of the earth, and in the relative positions of 

 land and water, by a change in the position of the axis of rotation, 

 was founded upon the absence of two considerations, both of 

 which appeared to him essential. These were — 



1. The dislocation of strata by cooling, 



2. The friction of the surface. 

 The latter consideration is apparently of but little importance ; 

 but with regard to the former, he pointed out how, if from any 

 cause the axis of rotation did not coincide with the axis of figure, 

 the pole of the axis of rotation would describe a spiral round the 

 pole of the axis of figure until it finally became, as it is at present, 

 identical with it. He considered it unlikely that originally the 

 axis of rotation should have coincided exactly with the axis of 

 figure, unless the whole globe were perfectly fluid ; but 

 added that we might go back to a time less remote, when the 

 earth was in a semifluid state, and in consequence of the different 

 degrees of fusibility of different substances, was partly solid, in 

 irregular masses, and the two axes did not, in consequence, coin- 

 cide. We might, he added, assume the original state of want of 

 uniformity between them to have been at a period even more 

 recent, when the earth consisted of land and water, and was 

 suited for the support of animal life. He then proceeds to show 

 how, if, after any length of time the solid spheroidal part of the 

 earth moved about any new axis of rotation, the water would 

 occupy a new position about a new equator, land would become 

 sea, and sea land, &c. 



He adds that if the axis of the earth would suffer a displace- 

 ment by reason of the causes which produce the precession of 

 the equinoxes, we should have another and more natural way of I 

 accounting for the existing phenomena ; but this has been held 

 to be impossible. 



I am not at present going to question whether this holding is 

 correct ; but with regard to Sir J. W. Lubbock's reasoning as to the 

 necessity of the axis of figure coinciding with that of rotation, it 

 appears to me of the greatest importance ; for if it hold good, any 

 alteration in figure cannot but have some effect on the position of 

 the axis of rotation. No doubt, if the whole globe, or even the 

 solid portion of it, were a regular spheroid, with a large 



