544 



NA TURE 



[August 9, 1894 



and Stokes. The former reported that a "course of experi- 

 mental physics is in itself desirable " ; the latter, that "there 

 woald be work enough in a large institution for a mathematician 

 and a physicist." 



In the end the Chair of Natural Philosophy was established, 

 and the fact that our host of to-day, Prof. Clifton, was its first 

 occupant reminds us how little we have advanced in lime and 

 how far in educational development from the days when pro- 

 positions such as those I have cited were only accepted on the 

 authority of the names of Slokes and De Morgan. 



The other fact to which I would refer is that the Clarendon 

 Laborator)', in which the meetings of Section .\ are to be held, 

 though erected barely a quarter of a century ago, was the first 

 laboratory in this country which was specially built and designed 

 for the study of experimental physics. It has served as a type. 

 Clerk Maxwell visited it while planning the Cavendish 

 Laboratory, and traces of Prof. Clifton's designs can be detected 

 in several of our university colleges. 



But though our surroundings remind us of the improvement 

 which has been effected in the equipment of our science, it would 

 not be difficult to indicate weak points which should forthwith 

 be strengthened. On these, in so far as they affect education, I 

 will not dwell — and that for two reasons. In the first place, we 

 meet to-day not as teachers, but as students ; and, secondly, I 

 think that whereas we have as a nation awoke — though late in 

 the day — to the importance of education, we are not yet fully 

 awake to the importance of learning. Our attitude in such 

 matters was exactly expressed by one of the most eminent of the 

 witnesses who gave evidence before the " Gresham Commis- 

 sion." In his opinion the advancement of knowledge must in a 

 university in London be secondary to the higher instruction of 

 the youth of London. If this be so — and I will not now dis- 

 pute it — we shall surely all agree that somewhere or other, in 

 London or out of it, included in our universities or separate from 

 them, there ou.;ht to be institutions in which the advancement 

 of knowledge is regarded as of primary and fundamental intere.st, 

 and not as a mere secondary by-product thrown off in the course 

 of more important operations. 



It is not essential that in such an institution research should 

 be the only task. Investigation may be combined with the 

 routine work of an observatory, with teaching, with the care of 

 standards, or with other similar duties. It is, however, essential 

 that, if the advancement of knowledge is seriously regarded as 

 an end worth attaining, it should not be relegated to a secondary 

 place. 



Time and opportunity must be found for investigation, as time 

 and opportunity are found for other tasks. It is not enough to 

 refer to research in a prospectus and then to leave it to be ac- 

 complished at odd times and in spare moments not claimed by 

 more urgent demands. Those to whom the fuiure of the higher 

 learning in England is dear must plan and scheme to promote 

 the life-long studies of men, as in the last quarter of a century 

 they have struggled, with marked success, to promote the pre- 

 paratory studies of boys and girls. That the assignment uf a 

 secondary position to research is the more popular view, and 

 that the necesiity for encouraging it has as yet hardly been 

 grasped by many of those who control our modem educational 

 movements is, I fear, too true. It is therefore a matter for con- 

 gratulation that within the last year Oxford has eslablishcl a 

 research decree, and has thus taken an important step towards 

 gathering within her fold workers of mature years who are able 

 and willing, not merely to gain knowledge, but to add to it. 



We may al.so note, with pleasure and gratitude, that the 

 strci- ' • • "• munificence h.Ts recently been in part directed 

 to !■ iient of learning. Sir Henry Thompson has 



genT ■■A a sum of £,yxx> lo provide a large photo- 



graphic telescope for the National Observatory at Greenwich. 

 The new instrument is to lie of 26 inches aperture and 22 fee! 

 6 inches focal length, or cxacily double the linear dimensions of 

 that which ha,s been previously employed. Mr. Ludwig Mond, 

 too, has added to his noble gifts lo science by the new research 

 laboratories which he i. alimii to establish in connection with 

 the Koyal Institution. Alt>cmarlc Street is Ihr >ngcd with 

 raemoriei of great discoveries. The researches of Lord Kay- 

 leigh and the remarkable results of Prof. Dewar's studies of 

 mailer at low temperatures are maintaining the great reputation 

 which the Kiy.il Inslilulion has gained in the past, and all 

 fcng!: "^ Hill rejoice that prospects of new and 



exECTi 'c o[>ening before it, 



Aii- , , :;iough very embarrassing fact is that the 



growth in the number of scientific workers makes it increasingly 

 difficult to find the funds which are necessary for the publication 

 of their work. Up to the present the author of a paper has had 

 to submit it to criticism, but, when it has been approved by 

 competent judges, it has been published without ado and without 

 expense to himself. This is as it should be. It is right that due 

 care should be exercised to prune away all unnecessary matter, 

 to reduce as far as may be the necessary cost. It will, 

 I however, be a great misfortune if judgment as to what 

 I curtailment is necessary is in future passed, not with the object 

 of removing what is really superfluous, but in obedience to the 

 iron rule of poverty, .\part from all other disadvantages, such 

 a course would add to the barriers which are dividing the 

 students of different sciences. \ few lines and a rough diagram 

 may suffice to show to experts what has been attempted and what 

 achieved, but there is no paper so difficult lo master as that 

 which assumes that the reader starts from the point of vantage 

 which months or years of study have enabled the author to 

 attain. Undue pruning will not make the tree of knowledge 

 more fruitful, and will certainly make it harder to climb. 



Connected also with the vast increase of scientific literature 

 is a growing necessity for the putlicalion of volumes of abstracts, 

 in which the main results of recent investigations are presented 

 in a concentrated form. English chemists have long been sup- 

 plied with these by the Chemical Society. The Physical 

 Society, though far less wealthy than its elder sister, has deter- 

 mined 10 undertake a similar task. We are compellei lo begin 

 cautiously, but in January next the first number of a monthly 

 pamphlet will be issued containing abstracts of all the papers 

 which appear in the principal foreign journals of Physics. In 

 this venture the Society will incur grave responsibilities, and I 

 avail myself of this opportunity to appeal to all British physi- 

 cists to support us in a work, the scope of which will be rapidly 

 extended if our first efforts succeed. 



From this brief glance at what has been or is about to be 

 done to promote the study of Physics, I must now turn to the 

 discussion of narrower but more definite problems, and I pre- 

 sume that I shall be most likely to deserve your attention if 

 I select a subject in which I am myself especially interested. 



During the last ten years my friend Dr. Thorpe and I have 

 been engaged upon a minu'.e magnetic survey of the United 

 Kingdom. The main conclusions at which we have arrived are 

 about to be published, and I do not propose to recount them 

 now. It is, however, impossible to give so long a ilme to a 

 single research without having one's attention drawn to a 

 number of points which require further investigation, and I 

 shall perhaps be making the best use of this opponunity if L 

 bring to your notice some matters in the practical and theoretical 

 study of terrestrial magnetism which deserve a fuller coii.sidcra- 

 tion than has yet been given lo them. 



In the first place, ihen, there is little doubt that the instru- 

 ments at present used lor measuring Declination and Horizontal 

 Force are affected with errors far greater than the error of 

 observation. 



We employed four magnetometers by Elliott Brothers, which 

 were frequently compared with the standard instrument at Kew. 

 These measurements proved thai the instrumental differences 

 which affect the accuracy of the declination and horizontal force 

 measurements are from live lo ten limes .as great .is the error of 

 a single field observation. The dip circle which two generations 

 ago was so untrustworthy is, in our experience, the most satis- 

 factory of the absolute instruments. 



In most cases these comparisons extended over several days,, 

 bul the Astronomer Koyal has described in his recent report 

 observations m.vle at Greenwich for two years and a half with 

 two horizontal force instruments. These differ between them- 

 selves, and the discrepancy is of the same order of magnitude 

 as those we have detected. 



If such differences exist between instruments of the Kew 

 pattern. It is probable that they will be sllll greater when the 

 magnetometers under investigation are of dilTerent types. 



This point has been investigated by Dr. Van Kijckevorsel, 

 who five years ago visited Kew, Pare St. .Maur, Wllhelmshaven, 

 and Utrecht, ami, using his own instruments at each place, 

 compared ihc v.alues of ihe magnetic elements determined by 

 himself with those deduced from the self-registering apparatus 

 of Ihe observatory. 



The discrepancie-- between the so-called standards, which 

 were thus brought to lighl, were quite startling, and prove the 

 necessity for an investigation as to their causes. 



NO. 1293, VOL. 50J 



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