444 



NATURE 



[March 13, 1879 



■we can ideally contemplate without error, but that which 

 we may act upon without fear ; and you cannot fail to see 

 that scientific thought is not an accompaniment or condi- 

 tion of human progress, but human progress itself." 



Several lectures delivered at St. George's Hall for the 

 Sunday Lecture Society, such as those on " Ether," 

 "Atoms," the "Sun's Place in the Universe," were all 

 characterised by his extraordinary power of explaining 

 some of the most difficult physical conceptions to a 

 popular audience, and were invariably listened to with 

 the greatest attention and pleasure. In his numerous 

 contributions to the Fortnightly, Contemporary, and Ni7ie- 

 teenth Century Reviews^ his outspoken earnestness of 

 purpose plainly showed the conscientious conviction of 

 the writer, and riveted the attention of his readers even 

 where they failed to convince. As many years secretary 

 and afterwards a vice-president of the Mathematical and 

 Physical Section of the British Association, he read 

 many short original papers on mathematical subjects at 

 the meetings, but it is to be regretted that no record of 

 most of these remains. In the last few months of his 

 active work, Clifford published the first part of a text- 

 book he had long contemplated, entitled the " Elements 

 of Dynamic." Bursting the bonds of the old method of 

 treatment of the subject by the cumbrous rectangular 

 coordinates, which had been so uncongenial to him in his 

 college days, he draws the student lightly and softly into 

 the toils of quaternions, thus almost imperceptibly intro- 

 ducing this simple and powerful method of analysis ; sad 

 it is indeed that his failing health did not allow him to 

 complete this work which would have long remained as a 

 valuable record of his method of teaching. Soon after 

 taking his degree he was elected to a fellowship at Trinity 

 College, and filled the post of assistant- tutor until his 

 election to the chair of Applied Mathematics and Me- 

 chanics at University College, London, in August, 1871, 

 which he held until his death. He was elected a Fellow 

 of the Royal Society, June, 1874. 



A critical examination of the value of his mathe- 

 matical labours cannot be attempted ; few, indeed, could 

 do justice to them ; but it is to be hoped that it 'may 

 not long remain undone. All that can be said in con- 

 cluding this brief sketch of his short and brilliant life 

 is to give expression to the regret so widely felt that it 

 was so prematurely cut off. He was — some of his friends 

 may think unfortunately — most generally known for his 

 philosophical and polemical writings. That his fame will 

 rest on no such narrow basis, the following list of papers 

 from the Royal Society Catalogue abundantly testifies : — 



1. "Analogues of Pascal's Theorem " (January, 1863), 

 Q,uart. Journ. Math., vi. 1863, p. 216, 



2. "Jacobians and Polar Opposites," Messenger Math., 

 ii. 1864, p. 229. 



3. " Analytical Metrics," August 30, 1864, Quart. Joiirn. 

 Math., vii. 1866, p. 54; viii. 1867, pp. 16, 119. 



4. "On the Principal Axes of a Rigid Body," Mes- 

 senger Math., iv, 1868, p. 78. 



5. " On the Theory of Distance," Brit. Assoc. Report, 

 1869, p. 9. 



6. "On the General Theory of Anharmonics," Lond. 

 Math. Soc, ii. 1869, p. 3. 



7. "On a Generalisation of the Theory of Polars" 

 <i868), Lond. Math. Soc, ii. 1869, p. 116. 



8. "On some of the Conditions of Mental Develop- 

 ment" (1868), Roy. Inst., v. 1869, p. 311. 



9. "On Syzygetic Relations among the Powers of 

 Linear Quantics" (1869), Lond. Math. Soc, iii. 1869-71, 

 p. 9. 



10. "On a Case of Evaporation in the Order of a 

 Resultant" (1870), Lond. Math. Soc, iii. p. 80. 



11. "On a Cononical Form of Spherical Harmonics," 

 Brit. Assoc. Report, 1871, p. 10. 



12. "Synthetic Proof of Miquel's Theorem," Mes- 

 senger Math., v. 1871, p. 124. 



13. " On a Theorem Relating to Polyhedra Analogous 

 to Mr. Cotterill's Theorem on Plane Polygons" (1872), 

 Lond. Math. Soc, iv. 1871, p. 178. 



14. " Geometry on an Ellipsoid " (l872X^ Lond. Math. 

 Soc, iv. 1871, p. 215. 



15. "Preliminary Sketch of Biquaternions," Lond. 

 Math. Soc, iv. 1873, p. 381. 



16. "On Mr. Spottiswoode' s Contact Problems," Roy. 

 Soc. Proc, xxi. 1873, p. 425. 



17. " Graphic Representation of the Harmonic Com- 

 ponents of a Periodic Motion" (1873), Messenger Math., 

 iii. 1874, p. 153. 



DAVID PAGE 



FEW names have been more familiar to general readers 

 in geology than that of this practised writer. Born 

 in Fife, his early years were spent in literary work of an 

 unambitious kind. Among other occupations he edited 

 for a time a newspaper in his native county. There used 

 to be a story told of his having temporarily edited also 

 the opposition paper during its editor's absence, and 

 having carried on a most lively warfare in the rival pages. 

 Whether well-founded or not, the story shows the estima- 

 tion in which he was held as a facile writer. He after- 

 wards entered into the employment of Messrs. W. and R. 

 Chambers, and for some years took an active part in the 

 preparation of their comprehensive series of educational 

 publications. It was while in this capacity that he wrote 

 his first introductory text -book of geology — a little volume 

 which had a large sale and proved singularly useful in 

 diffusing an elementary knowledge of the science. It was 

 also during Page's connection with the Messrs. Chambers 

 that the celebrated " Vestiges of the Natural History of 

 the Creation " appeared anonymously. Looking back upon 

 this now half-forgotten and superseded volume, it is hardly 

 credible that it should have excited such keen feeling and 

 passionate controversy. Having been the production of 

 more pens than one, it was never formally owned by any 

 one of its several authors. Robert Chambers was always 

 credited with the lion's share of it, but there can be 

 little doubt that he had powerful assistance from Page. 

 Quitting the service of Messrs. Chambers, Mr. Page 

 embarked on a career of successful authorship. He re- 

 wrote his " Introductory Text-Book of Geology," and 

 prepared an Advanced Text- Book on the same 

 science. He likewise published manuals on Physical 

 Geography, and from time to time issued various popular 

 works on geological subjects. These were always well 

 written. He had little original power as an observer, 

 though some of his work, particularly among the crus- 

 taceans and fishes of the Upper Silurian and Lower Old 

 Red Sandstones, shows considerable acumen, and raises a 

 surprise that he should not hare done more in that de- 

 partment. His great merit — and it is one which pro- 

 fessed students in science, immersed in their own original 

 inquiries, are apt to overlook and undervalue — was that 

 he had the power of seizing on the leading features of 

 scientific progress and discovery, and presenting them 

 clearly and vividly before non-scientific readers. He has 

 done good service in widening the circle of sympathy 

 with research, Jand for this chiefly he deserves to be 

 gratefully remembered by geologists. On the establish- 

 ment of the Newcastle College of Physical Science, in 

 connection with Durham University, he was chosen to 

 lecture on geology. He had already, however, had pre- 

 monitions of the paralytic affection which has at last 

 proved fatal. He was eventually relieved of the duties 

 of practically instructing his students in the field, this 

 part of the work of the college being undertaken by Mr. 

 Lebour. His failing health has for several years pre- 

 vented him from appearing at the meetings of the British 

 Association and elsewhere, as was his wont. He has at 

 last been removed from among us in his sixty-fifth year. 



