OF THE UNIVERSITY OF HATH-STAT. LIFE OF LORD KELVIN MACMILLAN AND CO., LIMITED LONDON BOMBAY CALCUTTA MELBOURNE THE MACMILLAN COMPANY NEW YORK BOSTON CHICAGO ATLANTA SAN FRANCISCO THE MACMILLAN CO. OF CANADA, LTD. TORONTO / vL sle 1 1 in -Lirui */UA j O/fi f/ /-s/tc/ffrM/i/i /// fff/f/rr/t < THE LIFE OF WILLIAM THOMSON BARON KELVIN OF LARGS BY SILVANUS P. THOMPSON IN TWO VOLUMES VOL. II MACMILLAN AND CO., LIMITED ST. MARTIN S STREET, LONDON 1910 QCiC MATU- STAT4 LIBRARY CONTENTS CHAPTER XV THE "LALLA ROOKH," THE BRITISH ASSOCIATION, AND THE " HOOPER " PAGES The Lalla Rookh, 585 ; Refitting for a Cruise, 585 ; Non-sectarian Education, 590 ; Work on the Yacht, 594 ; Reunion of Comrades in the C.U.M.S., 597; President of the British Association, 597 ; Introduced by Huxley, 599 ; The Address, 599 ; Effects of the Address, 609; Helmholtz visits Scotland, 612; Cruising, 614; Experiments on Ripples, 614; Prolongation of Galvano meter Patent, 619; The Western and Brazilian Telegraph Co., 624 ; Manufacturing the New Cable, 625 ; A Trip to Gibraltar, 626 ; Elected to Life Fellowship at Peterhouse, 628 ; The Hooper, 629 ; Scientific Work, 633 ; James Thomson appointed to the Glasgow Chair of Engineering, 634 ; The Hooper sails, 637 ; The Sounding Machine, 637 ; At Madeira, 637 ; The Misses Blandy, 638 ..... 585-639 CHAPTER XVI IN THE SEVENTIES A Cambridge Examinership, 640 ; President of the Royal Society of Edinburgh, 641 ; Inaugural Address to the Society of Telegraph Engineers, 642 ; To Madeira again, 645 ; Engagement to Miss Blandy, 645 ; Announcement of the Marriage, 647 ; " Nether- hall," 649; Prof. Andrew Gray s Reminiscences, 651; Wreck of the La Plata, 654 ; Owens College, Manchester, 655 ; Activities of the Period, 658 ; Lighthouses, 658 ; Visits America for the Centennial Exhibition at Philadelphia, 668 ; Thomson s Reports, 670 ; Bell s Telephone, 670 ; British Association Meeting V M777326 vi LIFE OF LORD KELVIN PAGES of 1876, 673 ; Helmholtz s opinion of Thomson, 677 ; Proposed as Master of Peterhouse, 679 ; The Compass, 679 ; The Sounding Machine, 68 1 ; Elected Foreign Associate of the Institut of France, 682 ; Electric Lighting and Transmission of Power, 683 ; Work on Elasticity, 686 ; Article on Heat, 688 ; Calculating Machines and James Thomson s Integrating Mechanism, 692 ; Refusal of the Cavendish Chair, 694 . . . 640-695 CHAPTER XVII NAVIGATION : THE COMPASS AND THE SOUNDING MACHINE Thomson s Love of the Sea, 696 ; His Contributions to Navigation, 697 ; The Kelvin Compass, 697 ; Defects of the Old Marine Compasses, 698 ; Thomson s Improvements, 702 ; His Account of the Invention, 705; The Astronomer-Royal s Opinion, 710; Admiralty Officials Objections and Apathy, 710 ; Adoption in the Navy, 715; James White, Optician, 717; The Sounding Machine, 719; The Depth Recorder, 723; Lighthouse Lights, 724 ; The Tides, 729 ; The Tide-Gauge, Tidal Harmonic Analyser, and Tide Predicter, 730 ; Admiralty Committee on Ships of War, 731 ; Designs of Dreadnotight and Indomi table, 735 ...... 696-735 CHAPTER XVIII GYROSTATICS AND WAVE MOTION Dynamics of Rotation, 736; Experiments on Spinning - Tops and Gyrostats, 737 ; Liquid Gyrostats, 740 ; Royal Institution Dis course on Elasticity, 743 ; The Vortex-Theory of Matter, 744 ; The Gyrostatic Compass, 745 ; Waves, 745 ; Lecture on Waves to the Institution of Mechanical Engineers, 748 . 736-752 CHAPTER XIX IN THE EIGHTIES Progress of Electric Lighting, 753 ; First Electrical Measuring Instru ments, 755; The Standard Electric Balance, 756; The British Association of 1880, 760; Revision of T and T , 761 ; The Faure Accumulator, 765 ; Promotion of a Company, 769 ; CONTENTS vii PAGES Thomson withdraws from the Promotion, 7 70 ; Address and Papers at the B.A. of 1881, 770; The Paris Electrical Con gress, 775 ; Lighting his House by Electricity, 776 ; The adjourned Paris Conference, 787 ; Lecture on Electrical Units to the Institution of Civil Engineers, 792 ; Address to the Midland Institute, 798 ; Awarded the Copley Medal, 799 ; Further work on Units, 800 ; Electrical Instruments, 804 ; B.A. Address at Montreal, 806 . . . . 753-809 CHAPTER XX THE BALTIMORE LECTURES The Johns Hopkins University, 810; Invitation to Thomson to Lecture, 811 ; The Audience, 814 ; Difficulties of accepting the Wave Theory of Light, 8 1 6 ; Equations of Motion in an Elastic Solid, 820 ; Difficulties in the Solid Elastic Theory, 822 ; Models and their Use, 834 .... ,, ..., 810-839 CHAPTER XXI GATHERING UP THE THREADS Third Refusal to go to Cambridge, 840 ; The Bangor Address, 845; Electrical Instruments, 846; Professorial Work, 851; Royal Institution Discourse on Capillary Attraction, 852 ; Politics : The Home Rule Bill, 856 ; Towage of a Boat, 864 ; Royal Institution Discourse on Age of the Sun s Heat, 865 ; Jubilee of the Electric Telegraph, 869 ; Work on the Partition of Space, 873 ; Doings at Netherhall, 876 ; The B.A. of 1888, 878 ; Presidential Address to the Institution of Electrical Engineers, 88 1 ; The Paris Electrical Congress and other Activities, 886; The Niagara Commission, 894; President of the Royal Society, 897 .... 840-904 CHAPTER XXII THE PEERAGE Offer of a Peerage, 905 ; The Name " Kelvin," 907 ; Politics, 911 ; Takes his Seat in the House of Lords, 913; Arms of Lord Kelvin, 914; Lecture on Navigation, 916; Death of viii LIFE OF LORD KELVIN PAGES Professor James Thomson, 918 ; Helmholtz Medallist, 922 ; Geological Echoes, 923 ; Account of a Visit to Netherhall, 926 ; Death of von Helmholtz, 938 ; Geology, 941 ; The Popular Lectures, 946 ; Centenary of the Institut of France, 947 : Illness, 953 ; Rontgen Rays, 954 ; The Petroleum Committee, 962 . . . . . . . 905-963 CHAPTER XXIII THE JUBILEE: RETIREMENT The Jubilee of Lord Kelvin, 964 ; The Conversazione, 965 ; Presentation of Addresses, 967 ; Conferring of Degrees, 975 ; Mascart s Address, 979 ; The Corporation Banquet, 981 ; Account of the Ceremonies, 988 ; White s Instrument Factory, 994 ; Royal Institution Discourse on Contact Electricity of Metals, 996 ; The Victoria Institute Address, 997 ; Meeting in Toronto, 1897, 1001 ; Death of Principal Caird, 1006; The Marconi Company, 1006 ; Visit to Rome, 1009 ; Retirement, ion . . . . . . . 964-1011 CHAPTER XXIV THE GREAT COMPREHENSIVE THEORY Hopes of a Molecular Theory of Matter, 1012; "Failure," 1013; A noble Ambition, 1013 ; Early Work, 1015 : Suggestion that Heat and Light are Electric, 1018 ; Electricity an essential Quality of Matter, 1020 ; Maxwell s Electromagnetic Theory of Light, 1 02 1 ; Thomson s Views, 1023; The Vortex - Atom Theory, 1027 ; "Steps towards a Kinetic Theory of Matter," 1032; The Philadelphia Lecture, 1035; The Baltimore Lectures, 1035 ; B.A. Discussion on Electromagnetic Matters, 1040 ; Presidential Address to the I.E.E., 1899, 1043; Abandonment of the Vortex- Atom Theory, 1046 ; The Molecular Constitution of Matter, 1050 ; Hertz s Work on Electric Waves, 1056 ; Rontgen Rays, 1061 ; "Failure," 1072; The Electron, 1074; Sir Joseph Larmor s Theory, 1075 ; Further Work, 1076 ; Com pletion of the Baltimore Lectures, 1080 . . 1012-1085 CONTENTS ix CHAPTER XXV VIEWS AND OPINIONS PAGES Religious Beliefs, 1086; Views on Life, 1092; Sir Edward Fry s Reminiscences of Visits to Netherhall, 1095 ; The Henslow Lectures, 1097; Spiritualism, 1104; Vivisection, 1105; Aversion from Controversy, 1108; His Humour, mo; Love of Music, mo; Precision in Language, 1117; Dr. Hutchison s Reminis cences, 1 121; Metaphysics, 1124; Politics, 1128; On University Organization, 1131 ; Changes in the Tripos, 1132; On Mathe matics, 1133; Newton and Kelvin, 1145 . . 1086-1146 CHAPTER XXVI THE CLOSING YEARS Phosphorescence, 1147; The End of the Century, 1150; Royal Institution Discourse on Clouds over Dynamical Theory, 1152 ; Mastership of the Clothworkers Company, 1154; Firm of Kelvin and James White, Ltd., 1155 ; The James Watt Oration, 1158 ; B.A. at Glasgow, 1160; Death of Tait, 1163; Visit to United States, 1164; Privy Counsellor, 1169; Order of Merit, 1170; Death of Stokes, 1173; Honorary Degrees at London University, 1175; and at the University of Wales, 1 1 79 ; Chancellor of Glas gow University, n8i ; Eightieth Birthday, 1181 ; B.A. at Cam bridge, 1182; Undergoes an Operation, 1187; Unveils Faraday Memorial, 1191; Presidency of Institution of Electrical Engineers, 1195; B.A. at Leicester, 1200; Illness of Lady Kelvin, 1202 ; Letters to Mascart, 1 204 ; Last Illness and Death, 1 208 ; Funeral in Westminster Abbey, 1209 . . . 1147-1213 APPENDICES A. List of Distinctions, Academic and other . . .1215 B. Part I. Printed Books ...... 1223 Part II. Scientific Communications and Addresses . . 1225 C. List of Patents . ...... 1275 INDEX ........ 1279 CHAPTER XV THE LALLA ROOKH, THE BRITISH ASSOCIATION, AND THE HOOPER BY the purchase of the Lalla Rookh, a smart sailing- yacht of 126 tons, Sir William Thomson became acquainted with navigation in a new phase. All his life he had been fond of sailing ; but by the possession of this craft he acquired at first hand a most intimate knowledge of seamanship and of its needs. For many years the cruises of the Lalla Rookh occupied a considerable part of the six months between the sessions of the University. When the end of October 1870 compelled him to lay her up in the Gareloch for the winter, he left her with regret. He looked keenly forward to the first of May when he should be able to join his ship. He was now planning an expedition to the Canaries, to be followed by an extensive cruise in the Hebrides with a party of scientific friends in the coming autumn, and it became necessary to fit out the yacht with furniture and bedding. To this end he took counsel with Mrs. Tait, resulting in a lively and characteristic correspondence : VOL. II 585 B 586 LIFE OF LORD KELVIN CHAP. GLASGOW COLLEGE, March 29, 1871. DEAR MRS. TAIT The question, cotton or linen, for the Lalla Rookhs berths has, after anxious consideration and consultation with naval experts, been decided in favour of linen. The cotton fabric seems to be too hygro- metric to be suitable for sea-going places. Will Glasgow do as well as Belfast for getting such a number (or area) as is required ? The area for mattress is approximately rectangular, and 3 ft. 9 i. by 7 ft. In fixing on the size of sheet I would wish to avoid an error which seems to have originated in the Levant prior to 725 B.C. (Isaiah xxviii. v. 20, second clause * of the v.), and which is still deplor ably prevalent at sea. I think I ought to have in all 1 2 pr., and therefore (as the acct. enclosed shows 4 pr. to be already provided) 8 pr., with the proper proportion of pillow slips, would be enough. The other things which I want are, so far as I can judge : 5 dozen towels, equal and similar to those provided by you for the N.P.L. [Natural Philosophy Laboratory.] 6 large bath sheets of similar material. Sometimes bath sheets are made thicker (apparently with the idea of maintaining a constant proportion of thickness to length or breadth), which is a mistake. 3^ dozen damask table napkins " double damask," I understand from T ; , has been decided. 10 tablecloths. I forgot to measure the table yester day when I was at Greenock to see the L. R., now fresh coppered and almost ready to be launched, but the dimensions will be sent to you by Captain Flarty. I think the best quality of damask should be taken for the tablecloths, as drops from the skylight, accidents through want of steadiness of platform, etc., etc., require the strongest resistance against shabbiness of appearance that the material can give. I should also have a proportionate quantity of glass- 1 [The verse in question runs "For the bed is shorter than that a man can stretch himself on it ; and the covering narrower than that he can wrap himself in it."] xv THE "LALLA ROOKH " 587 towels, cook s cloths, and dusters, which, with what I have already, should be enough to serve for several weeks away from port Whatever of the above is to be had best from Belfast, will you order it for me ? For the rest, any hints you can give will be gratefully received. I am not unconscious (but as much as possible the reverse) that I am asking a very great benefit, and taking advantage to the utmost of the promise you gave me to help me, when I write so troublesome a list of wants. But you must allow me absolutely to restrict your kind ness to ordering the things for me, and directing that the hemming and marking be done by the people who supply them, and who certainly will, if required, find persons ready to undertake those works. The Committee on Ships of War will continue its sittings during May, and I am afraid much of June, partly in London and partly at sea with the Channel Fleet. So I must give up Teneriffe for this year, which I do with great regret. Will you tell Guthrie l that I hope for another visit from him before May, as we got scarcely anything of the books done last time, there was so much time wasted on tops, etc. Could he not come from Ap. 1 8 to 27, which would include an opening cruise of the L. R. to Arran, Friday till Monday ? Yours always truly, WILLIAM THOMSON. The project of an autumn cruise with a party of scientific friends is set out in a letter to Helm- holtz, terminated by a postscript from Professor Tait :- GLASGOW COLLEGE, March 30/71. DEAR HELMHOLTZ I hope you will be able to come to the meeting of the British Association at Edinburgh in the first week of August. After it is over (and I wish it were over now, as I have the misfortune to be president- 1 Peter Guthrie Tait, his friend and colleague. 588 LIFE OF LORD KELVIN CHAP. elect) I want you to come and have a cruise for a few weeks among the Hebrides and West Highlands in a schooner of 128 X io 6 grammes, which will be my only summer quarters besides the new College here. I hope Tait will come too, but he has a great aversion to being afloat, and without the inducement of your company he would scarcely be persuadable. I would also ask Clerk Maxwell and Huxley and Tyndall, which would reach nearly to the capacity of the Lalla Rookh. Will you let me have a line when your plans are fixed ? Many thanks for your last letter. I hope the remaining anxieties of the campaign in respect to your son soon ceased, and that he has got through unhurt. I say nothing just now in reply to what you said about the sympathies of England. Believe me, yours always truly, WILLIAM THOMSON. On the last page of this letter Professor Tait wrote : DEAR PROF. HELMHOLTZ As Thomson has sent this through me, doubtless for some great moral purpose, I beg to add that I have no aversion to being afloat, but that I prefer to spend my few holidays in active physical work, such as the game of golf. Yours truly, P. G. TAIT. GLASGOW COLLEGE, April 9, 1871. DEAR MRS. TAIT Many thanks for your kind letter. I do not know the dimensions of the pillows, and could not well get them till Wednesday, as they are in store at Gourock. I think it would be safe to make the pillow slips of the same size as for land pillows, which, I sup pose, are something less than 3 ft. 9 in. long. If you think so you might let them be made accordingly. But in any case I shall have the dimensions of the actual pillows despatched by post from Gourock, addressed to you, on Wednesday. For the sheets I think 2^ yards might be rather short for Guthrie when he comes on a xv THE "LALLA ROOKH " 589 cruise with me. At sea it is desirable to have rather more of the sheet to turn over at the top than in beds less exposed to acceleration. Three yards would be a safe length. Two yards will be a very good breadth, sufficient even for sleeping through several tacks. I am very sorry to hear that Guthrie has been so ill. I cannot think it was good for him to allow Dr. Crum Brown to pull out a tooth. We regretted very much his not being here to meet Maxwell, Joule, etc. Do not let him shirk the August cruise with Helm- holtz, Huxley, Tyndall, and Maxwell, who I hope will all come. If the boat race is to be at all, it is right that Cam bridge should win, and they seem to have pulled splendidly last time. [April I, 1871.] I forgot that you had asked about the tablecloths. I am in a difficulty about them. I understood from Guthrie that the breadth determined the length, each being made one and indivisible in certain absolutely fixed proportions. I think the length 5 f. 4 i. must be when the table is at its shortest. But it is capable of prolongation, and I believe about 4 can sit on each side. The breadth you have is accurate. I shall write to you on Tuesday giving the maximum length. Believe me, yours very sincerely, W. THOMSON. ^ WESTERN CLUB, GLASGOW, Tuesday evening [April 1 1]. DEAR MRS. TAIT The L. R. table is, I find, of invariable length, and the values of the constants which you have are correct. Those of the T-cloths which you proposed are therefore no doubt perfectly right. The pillow-slip question is more difficult. An expert who has been employed on board told me that the pillows are presumably of the full breadths of the berths. If so there will be several different sizes. Captain Flarty will send you the length and breadth of each from Gourock as soon as possible, by to-morrow evening s post, I hope. I write in the greatest haste, as I am just going to sit 590 LIFE OF LORD KELVIN CHAP. (in the chair) at a meeting to promote united-non-sectarian- compulsory education on the same model as the Irish national education, which Roman Catholics, Presbyterians, and Church-people would not give fair play to in Ireland. The gathering referred to was a great public meeting in the City Hall. From Sir William s speech, as chairman, as reported in the Glasgow Herald, the following extracts are taken. After reading apologies for absence from influential representatives of the Free Church and the United Presbyterian Church, he said : He believed the feeling was very strong in these Churches generally in favour of the views to be advocated that night. What the meeting really desired was something very much analogous to that which had been given to England in the bill for national education which had now become law in that part of the United Kingdom. There were certain blots, undoubtedly, in the Scottish Education Bill, for what reason he knew not. It seemed to be supposed that Scotland required a more denomina tional, a more sectarian system of education than England. No mistake could be greater than this. Scotland, of all countries in Christendom, was the one most prepared, most ready to accept a united non - sectarian national system of education. Scotland was prepared to make this a thoroughly religious system. We were not here in Scotland to have a god less education. It would not be a godless education that would be supported by the Free Church, the United Presbyterian Church, and by the Established Church for the people of Scotland. What was desired was, in the first place, education in these elements of knowledge and art which were necessary for any religious education whatever. What was desired was to make religious education possible in the first place by the universal teaching of the arts of reading and writing, and to make this part of the national education compulsory. It seemed that opinion in England was strongly divided with reference to the question " compulsory or non-compulsory " ; but, on the other hand, it seemed that in Scotland there was a very strong feeling indeed among the people that compulsory education was desir able. If the people of Scotland desired compulsory education, xv THE "LALLA ROOKH " 591 he felt very confident indeed that they had only to say so, and it would be provided for them by Parliament. It was quite clear, however, that if education was to be compulsory, the national system of education in connection with which com pulsory statutes were founded must be unsectarian. There was one other point upon which Scotland desired something different from that which had ever been provided in England, and that was a degree of elasticity in the national system, in virtue of which it should not be confined merely to reading, writing, and arithmetic. Scotland did not desire schools from which the use of the globes should be excluded. A school without maps would not be satisfactory in any parish of Scotland, nor would a school be satisfactory without music. Later, in reference to one of the motions proposed, he said : The motion before the house did not propose to exclude the Bible from the schools. The Bible was truly and avowedly national, and he desired to ask the meeting to say that the motion which demanded a provision that no religious catechism, or formulary which is distinctive of any particular denomination, should be taught in the schools did not apply to the Bible. At the conclusion the chairman said he wished to call attention to the danger that hung over Scotland at present. Was Scotland, he asked, to be made the stepping-stone from the system of mild denominationalism in England, to utter and destructive denominationalism in Ireland ? Unless they resisted strenuously the efforts to carry the denominationalism proposed in this bill, Scotland would bitterly rue her part in such a matter. DEAR MRS. TAIT ^ About April 23 The L. R., unfortunately, was not ready for my proposed cruise at this time owing to the weather, which made communication with the shore at Gourock difficult. I trust she will be ready by Friday, but ready or not I sail on Friday southwards, and hope the E. wind will not stop till I reach Land s End. If the linen is not ready to cross from Belfast on Thursday it might come leisurely to the Admiralty, where I shall be on Wed. week, ditto fortnight, do. etc. Excuse great haste, and believe me, yours always W. THOMSON. 592 LIFE OF LORD KELVIN CHAP. [P.5.] Tell Guthrie I have no time to answer his letter to-day as I am overdue to go out to the Rouken. On May 5 he was at the Admiralty, but left that evening for Plymouth to sail in Plymouth Sound. L. R. t DARTMOUTH, May 8 [1871]. DEAR MRS. TAIT Since writing the above I have arrived in London. I made my first attempt to get a quiet forenoon of work yesterday in the L. R. (it being now Tuesday the pth) which, you may tell Guthrie, was very promising, although it only resulted in the miserable fiasco of twelve letters all " business," and of the most trivial but inevitable kind. However, I hope for better things. The only interruption in the course of three hours was a great trawler fouling me. The cutter and gig had both gone to shore, one for water and the other to land J. T. B. and his father, who went to take a walk and leave me quiet. The captain, steward, and cook were shoving her (the trawler) off when I came on deck on hearing the noise, and soon after we got her clear. " I hope there s nothing broke, sir ? " " No " (replied Captain F.). " I am glad to hear it, sir," were the last words from the trawler. I intended to write and give you a history of the voyage from the Clyde to Penzance, and how thoroughly enjoyed it was by J. T. B. and David King, the latter faintly denying that he would have enjoyed it still more if she had been on the slip at Greenock all the time. J. T. B. was more reticent, but I believe felt as deeply. I should also, if I had achieved my project of writing to you on board, have given you many details of a trip to the Eddystone and a voyage from Plymouth to Dartmouth against strong east wind. D. K. being replaced by J. T. B. s father. The latter remarked that the best thing about yachting was going on shore, an opinion in which I by no means concur. But all such matters rapidly lose importance, and the " log " that is not written during the voyage is never xv THE "LALLA ROOKH " 593 written at all. The one unforgettable thing is the linen and the marking of the kitchen towels, than which nothing could be better. I never attributed the marking to Guthrie, but only the address on the parcel from Edinburgh. Your most kind letter about the B.A. reached me here (London to-day). The five reasons are, each separately, irresistible. I shall certainly stay at 17 Drummond Place if I am able. I shall write as soon as I know. Tell Guthrie I am here (London) three days of every week l (address Athenaeum Club, Pall Mall). Therefore he may give high praise to the L. R. if I get, as I intend, two good working days weekly. Tell him also that I met Dr. Lyon Playfair just now, who told me that he had quite lately seen Dr. N. Arnott, and that the latter intends to give 1000 to each of the Scotch Univ ies , but that he has taken a crick, and though Mrs. N. A. had strongly urged Ed. as well as Glasgow (on account of the work done in the P. L? there) he was stiff about beginning with Glasgow for a trial. He remarked that I had not called the last time I was in London. I hope Guthrie s cold is better. Tell him that a good cruise in the L. R. will be requisite to brace him against these recurring attacks, which seem to be partially (if not wholly) due to overdoing the links. Will you not bring him with you to London when you come? Even that would do him good, and if you would both come from a Friday till Wednesday to the L. R. the cure would be complete. Monday Morning [May 15, 1871] TRAIN, WEYMOUTH TO LONDON. DEAR MRS. TAIT On receiving your most kind letter I wrote immediately to my sister 3 to ask if I might accept your invitation. I do not mean that I put it exactly in that way, but I pointed out forcibly how much 1 (Four days this week to-day for Admiral Halstead s fleet, and Sir Joseph Whitworth s ordnance.) Wed., Thurs., Frid. (from 12 till 5 in the Admiralty, except when it is II to 5 on account of extra tediousness of witnesses, or 9 till 6 Shoeburyness expedition as last week). 2 [Physical Laboratory.] 3 [Mrs. King, then resident in Edinburgh.] 594 LIFE OF LORD KELVIN CHAP. better she would be without me, and I said that you had very kindly invited me to stay at 17 D. P. [Drummond Place]. I received her answer just before setting out on a short tour on the Continent, from which I am now returning, and which has prevented me from earlier writing to you. I think that as I promised last Septem ber to stay with her, and she has Dr. Gladstone only, and says she would be greatly disappointed if I did not come, I am not free to do otherwise. I could easily prove this is a great advantage to you and Guthrie, but your letter disarms me, and I can only say that unless it were to be very different from all my visits to Greenhill Gardens and previous ones to D. P., it would have been one of the few pleasures that remain pleasures to me, to have the prospect of being at D. P. during the impending meeting. Often when kept in Glasgow by affairs or by his laboratory work, Sir William Thomson would retreat for the week-ends to his yacht to gain quiet and rest. If he had no relations or friends on board he would take his secretary with him, that he might get on with work. Rising early he would take a plunge, before breakfast, in the sea, swimming round the yacht, and in spite of his lame leg climb with agility on board by the rope. When there were no observations or soundings to take he would sit for hours with green book and pencil in hand working at calculations and meditating over his problems ; or he would pace the deck smoking a quiet cigar. Often he would work on far into the night. He was a daring navigator, and would sail far into the season when other yachts were laid up, sometimes in darkness and in severe weather. Once when he was sailing in the teeth of a gale xv THE "LALLA ROOKH " 595 his assistant John Tatlock, who often was with him as amanuensis, heard Captain Flarty saying half- aloud in Sir William s presence : " You will not rest till you have your boat at the bottom." He took no notice. He never seemed to tire. With all the sailors he was extremely popular ; their only grievance was that he would sometimes pop up on deck in the small hours of the morning to make sure that the watch was at his post and awake. In all the operations of sailing he took the keenest interest, and became a most expert navigator. Happy though he was to be thus alone, he was still happier if he could secure for a few days cruise his brother or some member of their related families, nephews or nieces, many of whom retain the most joyous recollections of the days spent on board the Lalla Rookh. Two short extracts from letters to Miss Jessie Crum show the use he made of his yacht : May i 5. Train, Weymouth to London. Monday morn ing. I received your letter on Friday afternoon just as I was leaving the Admiralty, and read it in the train on my way to Southampton to the L. R. May 1 7, Wedy. Athenceum. . . . Soon after daybreak (last) Saturday I sailed for Cherbourg ... to Portland on Sunday morning. Lord Dufferin is ordered by the Queen to Balmoral for 3 weeks, and the Committee is therefore adjourned until after the loth of June. I sail for Lisbon to-night. From Lisbon he sent Miss Crum a long letter about his doings there. The Lalla Rookh had 596 LIFE OF LORD KELVIN CHAP. sailed from Portland to the bar of Lisbon in 6 days 23 hours. On his return he wrote to Helmholtz : THE ATHENAEUM, June 14, 1871. MY DEAR HELMHOLTZ I have only this morning, on returning to London from a cruise to Lisbon and back in the Lalla Rookh, received your letter of the iith May. I am very sorry you will not be able to be at the meeting of the Association in Edinburgh and many others will be sorry also. But I am glad that you will come and sail with me in the West Highlands, and I shall take care to have the Lalla Rookh in a convenient position (probably in the Clyde or possibly Oban), at whatever time suits you. I asked Huxley and Tyndall to come for a cruise immediately after the meeting, but, unfortun ately, neither of them could accept, and I shall therefore most probably remain chiefly at the College in Glasgow after the meeting until your arrival. You must arrange to spend as much as possible of your holiday in Scotland, and if you wish to mix a little work with it as you did before in Arran, you will find writing not impossible in the Lalla Rookh. I congratulate you and M me> Helmholtz most sincerely on the safe return of your son from the war. Believe me, yours very truly, WILLIAM THOMSON. On June 24th he writes from the India Office, where he has been attending a meeting of the Examiners for the India Telegraph Service, telling of the progress of his Admiralty work. He is just going down to Portsmouth with William Froude to sail in the Lalla Rookh to Torquay. He has been staying in London with Dr. Gladstone ; J he has also given a party, of which he tells Miss Crum, 1 Dr. John Hall Gladstone, F.R.S., who had married the eldest daughter of Dr. David King. XV THE "LALLA ROOKH " 597 bringing together several of his old comrades in the C.U.M.S. : Blow, and Shedden and his wife completed the number, six in all. Pollock played the hautboy, Blow accompanied on the piano, and Blow played on the violin, unaccompanied. He did not play very much, as he had been playing in the Crystal Palace (last day of Handel Festival) " Israel in Egypt," and was tired, and only got up to London for 7.30 dinner. I had succeeded in getting the room James Bottomley recommended (as the one in which his chemical monthly dinners had taken place) and all went off very well. It was a strange reunion, like a return from the other world Shedden, Blow, Pollock, and myself, who had not been all together since the end of 1846, when Pollock, then a new-comer to Cambridge, quickly began to be intimate with Blow, Shedden, and me, just before Blow and Shedden were leaving Cambridge. I have often looked forward to such a reunion merely as an occasion when the music would have been a happy enjoyment. We had a visit from Blow at the Langham Hotel, but could not get any opportunity for music. It can never again be what it was, and it is too full of sadness for the present. On July i, he writes from Cowes that in the previous week he had sailed on Monday to Torquay, thence up to Southampton. On Wednesday he had run up to London to stay the night with Pollock at Hampstead. Lord and Lady Dufferin have come down to Cowes to yacht with him. " I have," he adds, " however, really found the L. R. the quietest and best place attainable for work." Work meant here the preparation of his Inaugural Address as President of the British Association, to be held on August 2nd, at Edinburgh. 59 8 LIFE OF LORD KELVIN CHAP. To his brother-in-law, Alexander Crum, he wrote : L. R., HURST ROAD, SOLENT, July n. My B. A. address destroys everything now. I cannot write a word of it, but it effectually prevents me from writing or doing anything else. . . . Helmholtz is coming from Germany for the sole purpose of a cruise about the 1 2th or 1 5th [of August]. . . . Shedden and his wife, W. Young, and a young man (Roberts) from the Nautical Almanac office, who has been calculating tides for me (as Brit. Ass. Committee) for four or five years, came down with me on Saturday for a few days cruise. July 1 8. Tuesday (Athenceuni}. . . . landed at Portsmouth this morning on my way to London. I have made some slight beginnings of actual writing for the Address, and have a great mass of matter, greater than I shall find space for, to bring in. My difficulty will be to get proper arrangement and condensation, and I feel as if it must necessarily be a very unsatisfactory thing at best. I had George King with me from Satur day till to-day. . . . George began the day by reading a number of chapters of ist Corinthians, and spent a great part of the remainder in writing for me, 1 towards the Address. I have taken some of the proceeds to the printers to-day, and hope to give some more instalments this week. I dine with Huxley alone to-day to talk over Asso ciation and other matters for the sake chiefly of my Address. I shall be here daily till Saturday, but am staying at Pollock s, Hampstead. On Sat. I go to the L. R. for quiet. Sir William Thomson s Presidency of the British Association, at Edinburgh, on August 2, 1871, was 1 [Mr. George King remembers how Sir William paced up and down the deck, dictating a few words at intervals, very slowly, making many corrections, while the yacht lay becalmed off Bournemouth.] xv THE BRITISH ASSOCIATION 599 an event of great importance. His Address was awaited with expectancy, for he was to be introduced by none other than Huxley, with whom he had crossed swords with knightly courtesy indeed, but with deadly earnest, in the matter of Geological Time ; and he was known to be opposed to some of the developments of the doctrines of Evolution that for a decade had been revolutionising men s minds as to the origin of things. Nor were the expectations of the assembled men of science dis appointed ; for the Address, though somewhat lengthy and discursive, proved of surpassing inter est. The assembly was a brilliant one. Huxley, the retiring President, was accompanied on the platform by the Emperor Dom Pedro of Brazil, and by a crowd of most distinguished savants, British and foreign, also by a number of the leading Pro fessors of the Scottish Universities. On rising to vacate the chair, he expressed cordial thanks to the officers and members for the support given to him, and congratulated the Association on the good work accomplished during the past year. Then turning toward the President-elect, he introduced him with exquisite courtesy in the words already quoted on p. 550 above. Sir William Thomson s address began with a reference to the origin of the British Association and the aims of its founders, in particular Brewster and Herschel, the latter of whom had passed away but two months before. He also referred to the recent death of De Morgan ; to the work of the 6oo LIFE OF LORD KELVIN CHAP. Meteorological Observatory at Kew since its estab lishment by the Association in 1842 ; and to the need of national laboratories for research. Our Government, he declared, fatally neglected the advancement of science. Glancing at the Reports on different branches of science, which had formed a conspicuous feature of the Association s past work, he particularised Cayley s Report of 1857 on Theoretical Dynamics, and Sabine s Report of 1838 on Terrestrial Magnetism, as having been of utmost service to scientific men, as well as of practical utility. He suggested the establishment of a British Year-book of Science as a need of the time. Then, turning to recent advances in par ticular branches, he pointed out that many of them owed their origin to protracted drudgery. " Accu rate and minute measurement," he said, "seems to the non-scientific imagination a less lofty and dig nified work than looking for something new. But nearly all the grandest discoveries of science have been but the rewards of accurate measurement and patient, long-continued labour in the minute sifting of numerical results." He instanced, as cases in point, the discovery of the theory of gravitation by Newton, that of specific inductive capacity by Fara day, that of thermodynamic law by Joule, and that of the continuity of the gaseous and liquid states by Andrews. Then he turned to the labours of Gauss and Weber, who had founded the absolute system of measurement of magnetism and electricity, and Weber s resulting discovery that the ratio of xv THE BRITISH ASSOCIATION 601 the electromagnetic and electrostatic units is a velocity. Maxwell he eulogised for his discovery that this velocity is physically related to the velocity of light. This led him to reflect how much science, even in its most lofty speculations, gains in return for benefits conferred by its application to promote the social and material welfare of man. " Those," he declared, "who perilled and lost their money in the original Atlantic Telegraph were impelled arid supported by a sense of the grandeur of their enter prise, and of the world-wide benefits which must flow from its success ; they were at the same time not unmoved by the beauty of the scientific prob lem directly presented to them ; but they little thought that it was to be through their work that the scientific world was to be instructed in a long- neglected and discredited fundamental discovery of Faraday s." Next, dealing with the kinetic theory of gases, which he described as the greatest achieve ment yet made in the molecular theory of matter, he particularly praised Clausius for having thus given the foundation for estimates of the absolute dimensions of atoms, and of their rates of diffusion. Maxwell had completed the dynamical explanation of the known properties of gases by bringing in viscosity and thermal conductivity. No such com prehensive molecular theory had ever been imagined before the nineteenth century ; but Sir William Thomson was not satisfied. Definite and complete as it seemed, it was yet but a part of a still more comprehensive theory in which all physical science VOL. II C 602 LIFE OF LORD KELVIN CHAP. would be represented with every property of matter shown in dynamical relation to the whole. But there could be no permanent satisfaction to the mind in explaining heat, light, elasticity, diffusion, electricity, and magnetism by statistics of great numbers of atoms, if all the while the properties of the atom itself are assumed. " When the theory, of which we have the first instalment in Clausius and Maxwell s work, is complete, we are but brought face to face with a superlatively grand question, What is the inner mechanism of the atom ? " This at once led to a sketch of the arguments by which he himself, in independence of Loschmidt and of Johnstone Stoney, had arrived at ideas about the size of atoms. He scorned to enter into any questions of priority in this affair. " Questions of personal priority, however interesting they may be to the persons concerned, sink into insignificance in the prospects of any gain into the secrets of nature." The atom must henceforth not be regarded as a mystic point endowed with inertia and attraction, nor as infinitely small and infinitely hard. It must be regarded as " a piece of matter with shape, motion, and laws of action, intelligible subjects of scientific investigation." The prismatic analysis of light here came in to reveal new facts as to atomic constitution. The observational and experimental foundations were the discovery by Fraunhofer of the coincidence of certain dark solar spectrum lines with bright lines in flames ; the rigorous test of this by Miller; the identification of the D-lines as xv THE BRITISH ASSOCIATION 603 belonging to sodium ; the discovery of Foucault (see p. 224) that the voltaic arc can emit the D-rays on its own account and at the same time absorb them when they come from another quarter ; the teachings of Stokes (see p. 300) as to the physical significance of the spectrum lines, and the inherent isochronism of the vibrations of an atom ; the in ferences from the dark lines as to the chemistry of the sun ; the prodigious and wearing toil of Kirchhoff, and of Angstrom, of Pliicker, and of Hittorf, in preparing spectrum maps and in identification of spectra under various physical conditions. The chemists, following Bunsen, discovered new metals ; biologists applied spectrum analysis to animal and vegetable substances ; and the astronomers, led by Huggins, carried spectroscopic research to the stars and comets. Well might the lecturer point out that " scientific wealth tends to accumulation accord ing to the law of compound interest." Solar and stellar chemistry had garnered great results. Rarely before in the history of science had enthusiastic perseverance, directed by penetrative genius, pro duced within ten years so brilliant a succession of discoveries. We were now to have a solar and stellar physics : for Miller, Huggins, and Max well had shown that the spectroscope afforded a means of measuring the relative velocity with which a star approaches to or recedes from the earth, and had found that not one of them had so great a velocity as 315 kilometres per second to or from the earth, a most momentous result in respect to 604 LIFE OF LORD KELVIN CHAP. cosmical dynamics. Then came a brief review of the nebular hypothesis of the solar system a hypothesis invented before the discovery of thermo dynamics, otherwise the nebulae would not have been supposed to be fiery. Helmholtz s supposi tion of 1854, that mutual gravitation between the parts of the original nebula might have generated the heat of the sun, had been extended by his own further suggestion that gravitation might account for all the heat, light, and motions in the universe ; while recent spectroscopic observation had shown that Tait s theory of comets, in which the head of the comet is regarded as a group of meteoric stones, furnished at least a probable explanation of that feature of their constitution. Astronomy and cosmical physics, therefore, well illustrated the truth that the essence of science consists in inferring, from phenomena which have come under? actual observation, the conditions that were antecedent, and in anticipating future evolutions. Even naturalists of the present day were not appalled or paralysed by the prodigious difficulties of acting up to this ideal. They were now struggling, boldly and laboriously, to pass out of the mere " Natural History stage," and to bring Zoology within the range of Natural Philosophy. But science brought a vast mass of inductive evidence against the hypothesis of spontaneous generation, to confute the idea that dead matter might have run together or crystallized or fermented into organic cells or germs or protoplasm. " Careful enough scrutiny xv THE BRITISH ASSOCIATION 605 has in every case up to the present day discovered life as antecedent to life. Dead matter cannot become living without coming under the influence of matter previously alive." " This," said Sir William, " seems to me as sure a teaching of science as the law of gravitation." " I confess to being deeply impressed by the evidence put before us by Professor Huxley ; and I am ready to adopt, as an article of scientific faith, true through all space and through all time, that life proceeds from life, and from nothing but life." The passage which followed startled even the most advanced thinkers present. " How, then, did life originate on the Earth ? Tracing the physical history of the Earth backwards on strict dynamical principles, we are brought to a red-hot melted globe on which no life could exist. Hence, when the Earth was first fit for life there was no living thing on it. There were rocks, solid and disintegrated, water, air all round, warmed and illuminated by a brilliant sun, ready to become a garden. Did grass and trees and flowers spring into existence, in all the fulness of ripe beauty, by a fiat of Creative Power ? or did vegetation, growing up from seed sown, spread and multiply over the whole Earth ? Science is bound, by the everlasting law of honour, to face fearlessly every problem which can fairly be presented to it. If a probable solution, consistent with the ordinary course of nature, can be found, we must not invoke an abnormal act of Creative Power. . . . When a volcanic island springs up from the sea, and after a 606 LIFE OF LORD KELVIN CHAP. few years is found clothed with vegetation, we do not hesitate to assume that seed has been wafted to it through the air, or floated to it on rafts. Is it not possible, and, if possible, is it not probable, that the beginning of vegetable life on the Earth is to be similarly explained ? Every year thousands, prob ably millions, of fragments of solid matter fall upon the Earth. Whence came these fragments ? What is the previous history of any one of them ? Was it created in the beginning of time an amorphous mass ? This idea is so unacceptable that, tacitly or explicitly, all men discard it. It is often assumed that all, and it is certain that some, meteoric stones are fragments which have been broken off from greater masses and launched free into space. . . . Should the time when this Earth comes into collision with another body, comparable in dimen sions with itself, be when it is clothed as at present with vegetation, many great and small fragments, carrying seed and living plants and animals, would undoubtedly be scattered through space. Hence and because we all confidently believe that there are at present, and have been from time im memorial, many worlds of life besides our own, we must regard it as probable in the highest degree that there are countless seed - bearing meteoric stones moving about through space. If at the present instant no life existed upon this Earth, one such stone falling upon it might, by what we blindly call natural causes, lead to its becoming covered with vegetation. I am fully conscious of the many xv THE BRITISH ASSOCIATION 607 scientific objections which may be urged against this hypothesis, but I believe them all to be answer able. . . . The hypothesis that [some] l life [has actually] originated on this Earth through moss- grown fragments from the ruins of another world may seem wild and visionary ; all I maintain is that it is not unscientific [and cannot rightly be said to be impossible]." A brief peroration touched the then burning question of Evolution versus Design. " From the Earth stocked with such vegetation as it could receive meteorically, to the Earth teeming with all the endless variety of plants and animals which now inhabit it, the step is prodigious ; yet, according to the doctrine of continuity, most ably laid before the Association by a predecessor in this chair, Mr. Grove, all creatures now living on earth have proceeded by orderly evolution 2 from some such origin." He then quoted from the conclusion of Darwin s great work on The Origin of Species, a couple of sentences about the numerous forms of life plants, birds, insects, worms different, inter dependent, yet " all produced by laws acting around us," and about the " grandeur in this view of life 1 The words in brackets were added by Lord Kelvin himself when he reprinted the address in 1 894 in vol. ii. of his Popular Lectures and Addresses. 2 Professor Huxley, in a later discourse, gently brushed aside the im portance of Thomson s suggestion in the following words : "I think it will be admitted that the germs brought to us by meteorites, if any, were not ova of elephants, nor of crocodiles ; not cocoa-nuts, nor acorns ; not even eggs of shell-fish or corals, but only those of the lowest forms of animal and vegetable life. Therefore, since it is proved that from a very remote epoch of geological time the earth has been peopled by a continual succession of the higher forms of animals and plants, these either must have been created or they have arisen by evolution. And in respect of certain groups of animals, the well- established facts of palaeontology leave no rational doubt that they arose by the latter method." 608 LIFE OF LORD KELVIN CHAP. with its several powers having been originally breathed by the Creator into a few forms or into one, from which endless forms, most beautiful and most wonderful, have been and are being evolved." Then he continued : " With the feeling expressed in these two sentences I most cordially sympathise. I have omitted two sentences which come between them, describing briefly the hypothesis of the origin of species by natural selection, because I have always felt that this hypothesis does not contain the true theory of evolution, if evolution there has been, in biology. Sir John Herschel, in expressing a favour able judgment on the hypothesis of zoological evo lution, with, however, some reservation in respect to the origin of man, objected to the doctrine of natural selection that it was too like the Laputan method of making books, and that it did not sufficiently take into account a continually guiding and controlling intelligence. This seems to me a most valuable and instructive criticism. I feel profoundly convinced that the argument of design has been greatly too much lost sight of in recent zoological speculation. Reaction against frivolities of teleology, such as are to be found, not rarely, in the notes of learned commentators on Paley s Natural Theology, has, I believe, had a temporary effect in turning attention from the solid and irre fragable argument so well put forward in that excellent old book. But overpoweringly strong proofs of intelligent and benevolent design lie all around us ; and if ever perplexities, whether xv THE BRITISH ASSOCIATION 609 metaphysical or scientific, turn us away from them for a time, they come back upon us with irresistible force, showing to us, through nature, the influence of a free will, and teaching us that all living beings depend on one ever-acting Creator and Ruler." Received with great applause, this address evoked many perplexities in its hearers. It was known that Sir William did not accept the doctrine of natural selection ; and many of the orthodox Scottish clergy, who looked to him for some pro nouncement, were aghast to find him appealing to the principle of continuity, and to discover that he was an evolutionist who, if he put back the origin of life on this earth to some distant globe or planet whence it had been meteorically introduced, would by an equal logical necessity put it back from such globe or planet to one yet more distant, and so on ad infinitum ; and they were disposed to regard him as a greater sinner against the then popular theology than even Darwin himself. Others seemed to regard the hypothesis of the meteoric introduction of life as a huge scientific joke. 1 Maxwell made it the subject of one of his rhyming jeux d esprit, which was sung at the Red Lion dinner. For two successive weeks Punch poked good-humoured fun at him in verse. The issue of August 12, 1871, contained a poem by Tom Taylor, entitled : " The Truth after Thomson, as versed by a Modern Athenian," a really clever summary of the address, from which we cull the following sample : 1 Vide, for example, St. Paul s Magazine, Sept. 1871. 6 io LIFE OF LORD KELVIN CHAP. But say, whence in those meteors life began, From whose collision came the germs of man ? Still hangs the veil across the searcher s track, We have but thrust the myst ry one stage back. Below the earth the elephant we ve found, Below him of the tortoise touched the ground ; But what the tortoise bears ? Dig as we will, Beneath us lies a deep unsounded still : Sink we with DARWIN, with ARGYLL aspire, Betwixt angelic or ascidian sire, Though ne er so high we soar, or deep we go, The infinite s above us and below : Beyond the creeds and fancies of the hour, Looms, fixed and awful, A Creative Power. In several successive years at the Association meetings Sir William reiterated his view. At Plymouth in 1877, when a certain meteorite (or model of it) was shown, he was keen to explain how, though the stone presented marks of fusion on the surface, the interior might have remained quite cool, so that if there had been in some deep crevice of it a bit of moss it would not have been burned; or if there had been lurking there a Colorado beetle it might have survived to become the father of a numerous progeny. Whereupon the witty Dr. Samuel Haughton remarked that he would not much mind the father-beetle coming in the crevice of a meteoric stone if only it had had the foresight to leave the old mother beetle at home ! The following letter of Feb. n, 1882, shows that Sir William persisted in his views. nth Feby. 82. DEAR DUKE OF ARGYLL I am much interested to see that independently you have come to the same con clusion regarding the source of all our terrestrial energy xv THE BRITISH ASSOCIATION 611 as I had been forced to come to a long time ago. You will see the thing referred to on page 22 of the enclosed address. It is more fully developed in an article under the title " On Mechanical antecedents of Motion, Heat, and Light," which is published in the British Association Report for 1854. As to the extract from The Times, which I return, the writer does not seem to have noticed that while saying that ardent faith in the existence of numerous inhabited worlds throughout space, such as Sir David Brewster had expressed, was more sentimental than scientific, I had myself expressed a very strong conviction, not only that there is life in other worlds than this, but that some of the life in this world is in all probability of meteoric origin ; and that I returned to the subject again and again in the British Association Meeting at York, and obtained the appointment of a Committee to investigate meteoric dust, chiefly with a view to ascertaining whether any of it contains either traces or actual specimens of life. . . . Believe me, yours very truly, WILLIAM THOMSON. Sir William Thomson also took part in the proceedings of the sectional meetings of the Asso ciation, and in presenting the Report of the Com mittee on Tidal Observations, added an extempore statement as to the determination of the amount of tide in the solid body of the globe, which he pro nounced to be far more rigid than a globe of glass of the same size would be. The Association over, Sir William Thomson hastened to the quiet of his yacht. During calm days he made some extremely interesting observa tions on the sets of capillary ripples which are originated in water streaming past a fixed narrow 612 LIFE OF LORD KELVIN CHAP. obstacle, such as a fishing line. These he described, with the theory of them, in letters to Tait, dated Aug. 1 6 and 23. They are reprinted in Appendix G of the Baltimore Lectures, 1904. On the 24th he was joined by Helmholtz, who came from Germany too late for the meetings. Helmholtz s letters to his wife give so graphic a picture of his Scottish friends and their activities, that a few extracts must be given. The extracts are taken from letters ranging from August 20 to Sep tember 14 : St. Andrews has a splendid bay, with fine sands which slope sharply up to the green links. The town itself is built on stony cliffs. There is a lively society of sea-side visitors, elegant ladies and children, and gentlemen in sporting costumes, who play golf. This is a kind of ball- game, which is played on the green sward with great vehemence by every male visitor, and by some of the ladies : a sort of ball game in which the ball lies on the ground and is continuously struck by special clubs until it is driven, with the fewest possible blows, into a hole, marked by a flag, about an English mile distant. The entire round over which each party wanders amounts to about ten English miles. They drive the ball enormously far at each blow. Mr. Tait knows of nothing else here but golfing. I had to go out with him ; my first strokes came off after that I hit either the ground or the air. Tait is a peculiar sort of savage ; lives here, as he says, only for his muscles, and it was not till to-day, Sunday, when he dared not play, and did not go to church either, that he could be brought to talk of rational matters. The Browns are also here, and he (Crum Brown) will accompany me to-morrow to Sir William. At dinner we had a chemist, Andrews, from Belfast, with his wife and daughter, and to-day Professor Huxley, the famous evolutionary xv HELMHOLTZ PAYS A VISIT 613 zoologist, all pleasant and interesting people. From Sir William we had yesterday two telegrams and two letters, to-day two telegrams with changing directions. The yacht squadron will sail earlier, and the latest instructions are that we go to-morrow evening to Glasgow to sleep in Thomson s house at the College, and on Tuesday join the yacht squadron at Inveraray on Loch Fyne. W. Thom son must be now just as much absorbed in yachting as Mr. Tait in golfing. (INVERARAY, Aug. 24, 1871.) I came yesterday with Professor Crum Brown, who luckily stuck to me till we reached the Lalla Rookh, in order to witness here the festivi ties of the clans-folk belonging to the Duke of Argyll at the reception of their future chieftainess, the Princess Louise. On Sunday we had dinner with Crum Brown, with whom is staying a great mathematician from London, Sylvester, in aspect extremely Jewish, but otherwise an important and presentable person. After dinner we had to leave the ladies and retreat to the smoking-room ; Tait would not allow anything else, but we got on well. Mr. Sylvester has been treated by Mr. Gladstone about as badly as could have happened at the hands of a Prussian Cultus- minister or even worse ; and there was great indignation about it expressed by the company. As to their attend ance at worship, they all excused themselves, as also did the ladies, on account of the rain. On Monday after noon I travelled with Prof. Crum Brown to Glasgow. In Glasgow we slept in College, where a nephew of W. Thomson did the honours. The interior of the house was not yet finished, neither carpeted nor painted, full of old furniture not yet put into place, and it produced an indescribably sad impression, as if no one cared about it, in contrast to the old house which Lady Thomson had managed. In one corner of the dining-room hung an exceedingly fine and expressive portrait of her, and below it the couch where she used to lie, and her coverlet. I was very sad and could scarce restrain my tears. It is very sad when men lose their wives, and their life is left desolate. . . . There are about forty yachts assembled 614 LIFE OF LORD KELVIN CHAP. here, slender and elegantly built ships, and some of them tolerably large. Thomson s belongs to the larger sort, is a two-master, and is quite commodious. At the moment, besides Professor Crum Brown and myself, there are, on the yacht, Thomson s two sisters-in-law, another relation Houldsworth, and a London physicist Gladstone. My cabin is just about so large that I can stand upright in it beside the narrow bed : the rest of the space is less lofty, yet it contains wash-table, dressing-table, and three drawers, so that I can arrange my things well. For washing the space is rather small, particularly when the ship rolls and one cannot stand firm. To-day we began the morning by running on deck wrapped in a plaid and sprang straight from bed into the water. After that an abundant breakfast was very pleasant. Then came visits to the other yachts, and so the day has up to now passed very pleasantly in spite of the rain. (GLASGOW COLLEGE, Sunday evening, Aug. 27.) Thurs day was still worse : we went to lunch on shore although the waves were already so high that the yachts began to be unsafe at anchor. We saw some Highland sports and dances. . . . Yesterday morning there was less wind, but sun and rain alternately. The morning was passed in preparations for departure, which was accomplished about one o clock. Thomson and his men manoeuvred the ship very cleverly, and the afternoon was passed with tolerably good weather, while we sailed back slowly along Loch Fyne. But then the wind caught us, and we went at a surprising speed the last two-thirds of our course to Greenock, the port for Glasgow. This evening we are to go with two nieces of Thomson s to Largs ; Monday to Belfast. On board the yacht they studied the theory of waves, "which," says Helmholtz, "he (Thomson) loved to treat as a kind of race between us." When Thomson had to go ashore at Inveraray for some hours, as he left he said : " Now, mind, xv A YACHTING CRUISE 615 Helmholtz, you re not to work at waves while I m away." On Aug. 3ist Sir William wrote to his sister, Mrs. King, from the yacht in Bangor Bay, County Down : I am just going to land along with Prof. Helmholtz, and Dr. Andrews, who came down last night and slept in the L. R.j to see a regatta to-day and accompany us to Clandeboye, Lord Dufferin s. We shall be at Clandeboye till after dinner to-morrow night, and then sail for Skye. Post Office, Portree, and, care of Professor Blackburn, Roshven, Fort William, are the best addresses. . . . We dined with James on Thursday after Helmholtz had an opportunity of seeing Dr. Andrews in his laboratory. . . . On Friday morning a party of twelve came down (Dr. and Mrs. Andrews and two daughters, Prof. Everett, and James and his family, and Mary Bottomley) making seventeen in all. . . . Late in the evening, a wonderfully beautiful moonlight night, Dr. A., J. T. B., Helmholtz, and I, drove down to Cultra and got on board the L. R. about midnight. We went on shore to breakfast with W. B. at Cultra this morning, and had a fine sailing- day for the regatta since. A U * 3 1 ) BELFAST. We arrived off Holywood about one o clock this afternoon. We do not leave till Sunday night about midnight, Lord Dufferin having asked Prof. Helmholtz and me to come to his house on Saturday to stay over the Sunday. After a very pleasant visit to Clandeboye they sailed from Belfast on Sunday night, but had very bad weather, which prostrated them all "even our Admiral," says Helmholtz. The party con sisted of Sir William, his brother, his brother-in- law, two nephews, and the Geheimrath. They visited Oban, Loch Etive, and Tobermory. Thence 616 LIFE OF LORD KELVIN CHAP. to Roshven, whence Heimholtz wrote on Sept. 9th : W. Th. was very eager to arrive here, where his colleague Mr. Blackburn, Prof, of Mathematics in Glasgow, has a lonely property, a very lovely spot on a bay between the loneliest mountains. The Atlantic showed itself this time very friendly, and we came quickly here, so that in the afternoon we could take an excursion with the family and dined with them. ... I expect that in the next day or so we shall abruptly begin our return, for Sir W. is very undecided as to the north side of Skye. . . . Mrs. B. has a remarkable talent for painting animals. She fashions all her doings and house hold ways to suit her professional tastes. ... It was all very friendly and unconstrained. W. Thomson presumed so far on the freedom of his surroundings that he always carried his mathematical note-book about with him, and as soon as anything occurred to him, in the midst of the company, he would begin to calculate, which was treated with a certain awe by the party. How would it be if I accustomed the Berliners to the same proceedings ? But the greatest naivete of all was when on the Friday he had invited all the party to the yacht, and then as soon as the ship was on her way, and every one was settled on deck as securely as might be in view of the rolling, he vanished into the cabin to make calcula tions there, while the company were left to entertain each other so long as they were in the vein ; naturally they were not exactly very lively. I allowed myself to seek amusement in balancing myself up and down on the deck, in wavering grace, and occasionally setting cataracts of sea-water to run off my waterproof. After cruising in the Sound of Skye they returned through the Sound of Mull, where, being becalmed, they made experiments on the velocity of propagation of the smallest ripples ill xv WAVES AND RIPPLES 617 that can be formed on water, and so back to Glasgow. L. R., LARGS BAY, Oct. 29, 71. DEAR HELMHOLTZ I have too long omitted to write to Du Bois Reymond in acknowledgment of the notice he sent me of my having been elected to the Berlin Academy. I received it on my way through Glasgow to the L. R. after the British Association, and left it in the house, which is now all in confusion, being handed over to painters and paperhangers. It may be some time yet before I can find the official intimation, and as I am anxious not to delay writing to Du Bois Reymond, you would oblige me much by telling me what is the proper designation of the Academy ? Imperial ? Royal ? Berlin Academy of Sciences, I presume ; also what is the designation of my own appointment corresponding member ? foreign member ? I hope you found all well at home when you arrived, and that all " went well " in respect to the marriage. I suppose you are now fairly launched on your University " Semester." Our " session " commences to-morrow week, and by this day week the Lalla Rookh will be at her winter moorings in the Gareloch. I have lived on board ever since you left (not merely because my house has been uninhabitable), but except two trips to Loch Fyne and two to Arran I have been chiefly between Largs and Greenock, and working hard at my reprint etc. of Electrostatics and Magnetism, which I am anxious to get launched before Christmas. It has been " on the stocks " for about five years. You should look at Cauchy and Poisson on Waves, the Concours de 1815, when you have time. The point lies in the evaluation of the function I cos mx* cos (/ ijgm)dm (for the case of motion in two dimensions) ; considered as a function of x it is a fluctuating function of a very curious character. We must have it tabulated by the British VOL. II D 618 LIFE OF LORD KELVIN CHAP. Association s Function -calculating Committee. Cauchy makes the thing very clear. Poisson I don t know so well yet. Both would be greatly improved by diagrams showing the forms of the waves and the laws of variation at different depths, etc. I was under a misapprehension when I spoke to you lately on the subject. I thought that a single disturbance at a point or along an infinite straight line, such as is produced by dipping a solid into water and not raising it out, but leaving it at rest, could not cause oscillations. What it does really is to cause a positive swell to spread out in each direction, followed by a series of undulations, negative and positive, finer and finer, and at any one place of the water, becoming finer and finer in length from crest to crest ultimately in proportion to ^ After ten or twenty waves have passed a point at distance x from the place of disturbance, the wave length (in the case of motion in two dimensions) is very approximately X or iirx\ gt* where x must be a large multiple of the diameter of the disturbing body, but a small fraction of \gfi. Did you meet Strutt * when you visited his family in England ? I hear that he would have been the new professor in Cambridge if Maxwell had not accepted. Believe me, yours always truly, WILLIAM THOMSON. On Nov. 2, still cruising off Largs, he wrote to Professor Andrews that he was awaiting Napier to make trials of his pressure - log, after which the yacht was to sail to winter quarters in the Gareloch. At the end of the cruising season he wrote to Dr. J. Hall Gladstone: 1 Lord Rayleigh. xv END OF THE YACHTING SEASON 619 LALLA ROOKH, GARELOCH, Nov. 4, 1871. MY DEAR GLADSTONE You have heard from my sister that I am to be in London this day week. Even should it not be convenient to you to let me stay with you this time, I hope to have the pleasure of seeing you in the course of the few days that I shall be in London. I do not, however, wish to delay so long answering about the Tidal Committee in reply to Mr. Unwin s letter. The present Committee of the British Association on Tides is a new one, which was appointed about four years ago, and has been continued from year to year since that time, with grants of money for calculating results of observa tions such as those given by tide-gauges, and generally for promoting the investigation of tides. . . . The Committee will be glad to receive the curves of the Calcutta Tide-gauge, and to apply the method of reduction which we have been following if we find that it can be done with advantage. . . . I am now on the point of " flitting," as we say in Scotland, from my summer quarters on board the Lalla Rookh to the College. I am alone with one man on board waiting for my train, the others having just sailed away in the " cutter " and " gig " for Greenock to leave the boats there for the winter, and to find places, chiefly no doubt in foreign going ships, for themselves. . . . Believe me, yours always truly, WILLIAM THOMSON. The business in London was a petition for the prolongation of the patent for the mirror galvano meter. Sir John Karslake, Q.C., was counsel for the petitioner ; Mr. Archibald for the Crown. Six weeks later Sir William wrote to his assistant, Mr. Leitch, who was in charge of the recorder at Suez : Dec. 14, 1871. MY DEAR LEITCH . . . Ten days ago the Privy Council gave me a prolongation for 8 years of my 620 LIFE OF LORD KELVIN CHAP. 1858 patent. My formal petition for the prolongation was made last summer, and the three cis-Indian and the three ultra - Indian Companies all lodged objections. They, however, withdrew their objections before the petition was heard, and promoted rather than opposed my case. I also got assistance from Sir C. Lampson, who was deputy -chairman of the Atlantic Telegraph Company, and from Mr. Saward, their secretary. Also Mr. Willoughby Smith, Sir James Anderson, Sir Daniel Gooch, Captain Sherard Osborne, Mr. Fender, and other influential people in the companies were favourable. . . . Yours truly, W. THOMSON. Further details are given in a letter to Miss Jessie Crum, then abroad : GLASGOW UNIVERSITY, Dec. 12, 1871. DEAR JESSIE I have been hearing of you all in several indirect ways, the last of which was Mary s letter to Dr. Rainy, which he brought to me one day. I hope you are getting on well, and feeling comfortable in your villa. I should be much obliged by a letter from either you or Mary, when you have time to write. You must look upon this simply as a begging letter. I cannot give any thing in return for what I have been asking, as the things I have been kept incessantly busy with are dull and uninteresting, except so far as getting through little by little what must be done is interesting. I was in London again from Saturday last till Wed nesday about my petition for prolongation of my 1858 patent. I had been warned by Grove (who was my counsel until he was promoted to be a judge) to expect nothing, and to consider that even a prolongation for one year would be a good result. The Privy Council gave 8 years. The case altogether went off very well. The judges early intimated that they did not require any more evidence as to the " merits of the invention," and they showed a liberal spirit in respect to accounts, etc. xv PROLONGATION OF PATENT 621 Varley had prepared an admirable apparatus for illus trating the action of my mirror instrument, and showed it in action to the judges, which had a very good effect. The Telegraph Companies (8 now in all) with whom I have come to agreement are all very pleasant and friendly, and the new instrument is making its way eastwards (now as far as Suez, and going off to-day to Aden and Bombay). Until the time when I was coming home from Brest, when we were at Barra House, there was nothing settled. As soon as anything should be settled, it went into unsettlement, with another prospect of a lawsuit, again up till that time. I well remember the warm congratula tions and sympathy we had when we hurried home from Kissingen the year before, and things seemed to be settled in London. Then I went off again, and all the winter we were in Edinburgh it was a subject of anxiety to my dearest Margaret. It was not till the August following that I could tell her it was all settled. Since that time those things have gone as prosperously in every respect as possible ; but she only knew the perturbations and toils, from some of which she suffered greatly by over-fatigue going to Valencia in 1858. Near the end of April, when very good accounts of the new instrument came from St. Pierre, and the Indian Companies were all wanting to have it, she said, " It is just the fruit of your labours." I must stop now, and go on with my book on Electricity, which is chiefly compiled from things written more than twenty years ago, and some which I wrote in Edinburgh the last winter we were there. Macmillan is pressing me to get it out by Christmas, if possible, and I am at it every moment of spare time. With love to your mother and Mary, I am, yours always affectionately, WiLLIAM THOMSON. In January 1872 Sir William was busy over the proofs of his reprint of papers on Electrostatics and Magnetism, which had been on hand for four years. In February he was in London with Dr. Gladstone ; 622 LIFE OF LORD KELVIN CHAP. then went to Edinburgh to work with Tait at proofs of the smaller Elements of Nat^lral Philosophy, for the Oxford Press (see p. 472). On March 29 he wrote of his doings to Miss Jessie Crum : new cable schemes, trials of telegraph instruments old and new, correspond ence "with my old friend De Sauty, and several others of the old Atlantic people, who are all much taken up with the recorder, and (under instructions from Sir James Anderson) doing their best to get it to work well." He is proposing a short spring cruise before session ends, and then to sail to Gibraltar to see the recorder working there. He has a prospect, after the British Asso ciation is over, at the end of August, of going to Quebec with Dr. Norman Macleod, but the project was cut short by the death of Dr. Macleod in June. Two of his nephews will be required as lieutenants in the new Atlantic cable scheme. " There is quite an epidemic amongst the laboratory students of desire to become telegraph engineers." Then comes a commercial shadow across the path. GLASGOW UNIVERSITY, 3 April, 1872. DEAR JENKIN I am sorry to hear what you tell me. I have no confidence in B , and would require any statements as to the use of the mirror to be very carefully sifted before we can admit them. It would be necessary for him actually to have used the mirror on the cable, and also at a time found inconsistent with my claims, before we could admit any weight to the objection to our rights. Find out, if possible, taking whatever law advice is necessary, to what extent experimental use of an xv MORE CABLE PROJECTS 623 invention in that way, confessedly mine, can invalidate my claim. If he only experimented with it on the cable, and did not use it for practical working on the line, I do not believe his objection will be valid. Try, however, if possible, should the case look bad against us, to make a compromise, as the companies no doubt admit the moral right. Of course we know that directors can t be generous with their shareholders money, but the proper mixture of generosity and worldly wisdom, escaping litigation, and procuring us as allies and assistants to their signalling arrangements, may commend itself to them. We have another string to our bow in the recorder. For all their lines it must cut out the mirror, and that speedily. But be cautious in using or showing this string. If we can get our terms for the mirror con sented to, we can make more use of our recorder rights than if we put them forward now. In the course of six months, I believe, I could give thorough good recorders for their lines. You may feel confident as to this, and use it as you think best. Yours truly, WILLIAM THOMSON. By April 1 1 he is able to send word to Leitch that Sir James Anderson now considers the re corder to be the instrument for all their cable stations. On April 28 he writes again, from London, he has been suddenly called up on business of the " Great Western Telegraph Co."; that he intends to go to J. T. Bottomley s marriage at Belfast ; and that on Friday he hopes to be at rest on his yacht in the Gareloch, ready to put to sea. He is wishing to sail for Gibraltar as soon as possible, that he may be free to go later to Bermuda. " On Friday I got the last MSS. of the book out of hands." 624 LIFE OF LORD KELVIN CHAP. The Great Western Telegraph Company was a project to lay a cable via Madeira and the Bermudas to Boston and to the West Indies ; but later by arrangement with the earlier companies the project was altered, though the cable for this work had been manufactured and the ship Hooper specially designed for laying it ; and it became merged in the Western and Brazilian Telegraph Co., which laid cables in five sections from Para to Rio Janeiro, touching at Pernambuco. Eventually this and other South American cables were taken over by the London Platino- Brazilian Telegraph Company. About June ist Sir William wrote to Helm- holtz :- 50 GROSVENOR PLACE, LONDON, S.W. DEAR HELMHOLTZ I am going to Scotland to-night, and return to London about the middle of next week, to spend two days in this house (of Mr. Spottis- woode, President of the London Mathematical Society). On Saturday the 2ist I hope to sail from Torquay for Gibraltar, and to call at London on my way back, visiting the telegraph stations at both places, my recorder being now in constant use there. There is now a great telegraph project in the course of execution to lay cables from England to Bermuda, and then to New York and St. Thomas. The manufacture of the cables has commenced, and Fleeming Jenkin and I being engineers to the Company are obliged one or other of us to be very frequently in London. We have a great deal of electric testing to do insulation, electro static capacity, and resistance of the copper conductor, also testing the strength of the iron wire and of the finished cable. The laying will not be commenced till this time next year. I am living chiefly on board the Lalla Rookh) off the south of England, and coming up to XV THE "HOOPER" 625 London when necessary. I can only get mathematical work done in the yacht, as elsewhere there are too many interruptions. A few days ago I despatched the very last of my volume of Electrostatics and Magnetism to the printers, except the preface, and I am now getting to work on Vol. II. of the Natural Philosophy, and the reprint of Vol. I. I hope you have been well, and your family all well, since we parted at the " Albert Quay." Is your new laboratory finished or making satisfactory progress ? I hope it will turn out in all respects satisfactory to you. Believe me, yours very truly, WILLIAM THOMSON. By this time the new company was fairly afloat, and the partners had to keep a staff of electricians at work, some at Millwall, others at Mitcham under David T. King, to superintend the manufacture. Sir William had to spend two or three days each week at the works. He has a way of turning up at the Millwall works on a surprise visit, arriving once at 2 A.M. in a dripping mackintosh, with a black bag in his hand, "for all the world like a tea-traveller," as one of the assistants writes. He is living the rest of his days on his yacht, cruising round Torquay, or taking his friends Dr. Gladstone, Mr. Varley, and Dr. Siemens trips to Sheerness or Margate. He varied these amusements by reading to the London Mathematical Society a paper on the reduction of Polynomial Quadratics, which he had worked out in the quietude of his yacht. On June 24th he wrote to Lord Rayleigh, from 626 LIFE OF LORD KELVIN CHAP. Torquay, respecting certain paragraphs of " the book " : I am on the wing for Gibraltar (and other telegraph stations Lisbon, Brest if time before the B. A., Brighton, Aug. 14, permits). I hope to despatch from Gibraltar all I have to say in the way of additions or amendments to the first two or three sheets of Vol. I., so that the reprint may go on forthwith. Meantime, or as soon as possible, amendments or suggestions for early parts or any part of the volume sent to Tait will be thankfully received. Then he sails for Gibraltar one Sunday morning from Gravesend. But just as they weigh anchor the " Thames Mission " boat comes up, and Sir William orders Captain Flarty to stop the yacht while the minister conducts service for them on board. By June 24th he has got to Torquay, and has taken aboard the new recorder for Gibraltar, and some new instruments for sounding and for measuring speed at sea. While he is away affairs at home do not flag. White is pushing on with im proved recorders; and Donald MacFarlane, writing him to report progress of the laboratory work in the new building of the University, says : " I have taken possession of the spare room above the stair case (without leave), and in one corner of it I have stowed all the packing-boxes which were always in the way." Returning to England, August ist, he writes in the train, from London to Torquay, to his sister-in- law a detailed account of his tour : I have had a very pleasant and satisfactory cruise, and xv A MEDITERRANEAN CRUISE 627 made useful as well as interesting visits to the three tele graph stations, Gibraltar, Lisbon, and Porthcurno (though only three hours at the last in consequence of a letter, reinforced by a telegram, summoning me to attend a meeting of the " Great Western Tel." Board in London yesterday). At Gibraltar my old enemy, but now very good friend, De Sauty, who was at the other end of the cable in 1858, has managed admirably with the recorder, and has entirely given up the mirror in all the work of the station. I found him as agreeable and obliging as possible in every way. We were almost constantly at work in the telegraph office from the Sunday * morning, when I arrived, till the Saturday morning, when I sailed for Lisbon. . . . The rest of the letter is full, moreover, of lively details about the monkeys on the Rock of Gibraltar that came early in the morning to visit the telegraph station there ; of his trip towards Algiers in the Lalla Rookh with De Sauty on board ; and of his voyage home via Lisbon. To-morrow he will sail from Torquay to Cowes for the R. Y. S. Regatta. Brighton was the scene of the British Associa tion meeting of 1872, and Sir William went there for three days to introduce his successor, Dr. Carpenter, into the presidential chair, and to read two papers one on the Identification of Lights at Sea, the other on the Use of Steel Wire for Deep Sea Sounding. In the latter he narrates how in the Bay of Biscay he has corrected the charts, using 1 " Particularly the Sunday, which at all the stations of submarine lines is the great day for testings and adjustments, lawful on the ground of necessity and mercy. About five o clock on the Sunday the cable has generally done its week s work, and is nearly at rest till about eleven on Monday forenoon ; but for three weeks together it has been never once clear, which is about as bad as Mr. Pickwick s cab horse," 628 LIFE OF LORD KELVIN CHAP. a lead sinker of only thirty pounds at the end of a three-mile line of thin pianoforte wire. At the Mathematical and Physical Section, in proposing a vote of thanks to the president, who had referred to Professor Zollner s electric theory of comet s tails, he told how some time since, at a workmen s philosophical institute at Millwall, an intelligent man produced a glass tube which cracked when an iron wire was laid along its inside. The workmen were puzzled by the fact, but at last agreed that it must be electrical ! The same merit lay at the bottom of Zollner s theory, namely, omne ignotum pro electrico. More cruising about the Clyde completes the holiday, and in September he is back at the University. In October 1872 Sir William Thomson was elected to one of the two life Fellowships at Peter- house, founded for men distinguished in Science or Letters ; the eminent Greek scholar, Richard Shilleto, having been elected to the other in 1867. There was now big work in hand over the manufacture of the new cable, and the building of the cable-ship for laying it. He seeks advice from his engineering brother : GREAT WESTERN TEL. Co., 103 CANON STREET, LONDON, Oct. 30, 1872. MY DEAR JAMES Hooper s Telegraph manufactur ing company have ordered for cable laying a ship 350 ft. long, 55 ft. beam, 36 ft. moulded depth; builders measurem 1 = 4940 tons. XY THE "HOOPER" 629 Jenkin and I both strongly urge a hydraulic arrange ment to give power of manoeuvre that is to say, a pump and water pipes to give means of discharging water perpendicu- larly across the length at any one of four places, A, A , B, B , or at two of them simultaneously. I calculate that water discharged through an aperture of J square metre (say 2^- square feet) at a velocity of 6^ metres per second, that is to say, -5 or i~ tons per second, would 4 16 give a pressure of one ton. I would wish to be able to give at least I ton simultaneously at A and B, and therefore would need to be able to discharge not less than 3^- tons per second, or 728 gallons per second, or say 44,000 gallons per minute. The head of water corresponding to the discharge velocity of 6j metres per (6 1 ) 2 sec. is g = 2 metres. I should be much obliged by your telegraphing to me to above address on Friday morning your opinion as to the centrifugal pump and water-ways that would be required for this, and your opinion regarding Gwynne s pumps, of which I send you printed prospectus by same post with this. You might also write to me on Friday, addressing St. Peter s College, Cambridge. . . . The ship is to be made by Mitchell, Newcastle, and it is to be finished and round in the Thames by 26 April, subject to 100 penalty per day for delay after that date. I was made a Fellow of Peterhouse under a new statute which allows men eminent in literature or science to be elected independently of marriage. I shall go back to Cambridge on Saturday on my way to Glasgow. Your affectionate brother, W. THOMSON. GLASGOW COLLEGE, Nov. 5, 1872. DEAR JAMES I think the hydraulic thwart ship propeller, according to the data of your telegram, will do. I spent yesterday at Newcastle with the shipbuilder (Mr. 630 LIFE OF LORD KELVIN CHAP. Swan of " Mitchell and Co."), and he has found a place for it ... [here follow ten octavo pages of details] . . . The thing is of extreme urgency, as in three weeks the plating of the ship about the stern will have commenced. Many of the frames are up already. I only heard on Thursday last that she was to be built. I wish they had told me beforehand, and I would have had a thwartship propeller in the original plans, which would have saved a good deal of money on what will have now to be spent to get it applied. Your professional charge and expenses must be charged, with the wheel and work of the ship builders putting it in, to Hooper s Company. If we can get a practicable scheme, it is, I think, certain that the Company will adopt it In haste, your affec 1 brother, W. THOMSON. UNIVERSITY, EDINBURGH, Monday \Nov. 1 8, 1872, Post-mark]. DEAR JAMES Thanks for your telegram. Mitchell s are quite confident about thwartship screw below main screw shaft, 6 ft. diameter of screw. Three blades to be driven by a wire rope round grooved rim 6 ft. diameter surround ing blades of screw. You will receive in a few days from me (or from Mr. Froude) their drawings. The engine is to be on deck, and I have a telegram from them to-day (scarcely time to have read it yet) to effect that we may have 60 Ibs. pressure, and no limit to size of cylinders. Yours, W. T. Great haste. Sir William was at this time living in his half- furnished residence in the professors court at the University, his nephew, James T. Bottomley, resid ing with him and acting as assistant in his laboratory work and teaching. A well-known feature of his household was " Dr. Redtail," a grey parrot with red tail feathers, who had been bought in Seven Dials. Of this favourite bird many stories are told. xv AN INVITATION TO HELMHOLTZ 631 The best authenticated is his greeting of his master as he hurried in from the laboratory to join an in vited party at lunch : " Late again, Sir William ! Late again ! " At the end of the year he has a proposal to convey to Helmholtz : ATHENAEUM CLUB, LONDON, Dec. 2, 1872. DEAR HELMHOLTZ I enclose a letter of Dr. Cookson, Master of Peterhouse and Vice-Chancellor of the Uni versity of Cambridge, which he requested me to transmit to you. It is written in consequence of a suggestion I made to him when I saw him three days ago at Cambridge, that he should ask you to give the " Rede Lecture " for 1873. I hope you will accept. You would choose your own subject anything upon which you would like to speak for an hour, or an hour and a half, to a cultivated audience. It is given annually in the Senate House of the University, and the authorities are always anxious to have a man of high distinction. So far as I know, no one not a British subject has hitherto been asked to give the lecture. You would probably, if you accept, prefer to have the lecture fully written out, and to read it to the audience. It is desirable that it should be afterwards published. In 1866 I was asked to give the "Rede Lecture." I accepted, and chose for my subject the " Dissipation of Energy." I did not succeed in getting it written out, and it has not been published, but I hope sometime to write it out (with, no doubt, many changes and additions) and to publish it. I hope very much you will be able and willing to accept. I would make a point of being at Cambridge at the time. Dr. Cookson will be glad to hear from you as soon as may be in reply. Address, The Rev. Dr. Cookson, Master of Peterhouse, Cambridge. I hope all goes well with you at Berlin. I should be glad to hear from you. I am here for a few days on telegraph business, and I go 632 LIFE OF LORD KELVIN CHAP. to-morrow to Cornwall to test a new cable which has been just laid from the Lizard to Bilbao. I shall be in Glasgow again by next Monday, I trust. I shall send you very soon a printed paper describing the best way I have found for managing the large tray battery, which has been doing well. I am getting a battery of eighty trays of larger size l than those you have, and I expect to get a very powerful electric light from it. Believe me, yours always truly, WILLIAM THOMSON. P.S. With trays the same size as yours, I get the resistance of each cell as low as -12 of an ohm. GLASGOW COLLEGE, Jan. 8, 1873. MY DEAR HELMHOLTZ We are very sorry that you are unable to undertake the " Rede Lecture." I cannot share your misgivings about success in interesting the audience had you been able to undertake it, but only regret that your engagements in Berlin make it impossible for you to do so. You have heard, no doubt, before now of the sad loss we have had in the death of Rankine. I send you by this post a copy of the Glasgow Herald (Dec. 28), con taining an article on his life and scientific work by Tait ; also a copy of the same newspaper for Dec. 26, containing two articles, all of which I think will interest you. We lost Archibald Smith, 2 too, in the same week, whose name you may know from the great work he has done for navigation in respect to correcting the compass error in iron ships. He was a very old and excellent friend of mine. He has been a hard-working Chancery barrister almost ever since he took his degree at Cambridge as "Senior Wrangler" in 1836, or else he must, with his great mathematical powers and inclination for physical science, have been one of the foremost men of science of this country. I have urged my brother, James Thomson (who is at present Professor of Engineering in Queen s College, Belfast,. 1 The zincs 22 inches square. a [See Obituary Notice by Sir W. T., Proc. Roy. Soc. xxii., pp. i.-xxiv.] xv SOCIETY OF TELEGRAPH ENGINEERS 633 and has been so for many years) to apply for Rankine s vacant chair. I should feel much obliged by your writing to me a very short statement of your opinion of my brother s merits as a scientific investigator, or qualifica tions for a chair of Engineering. I have received such letters to-day from Andrews, Tait, and Joule, in answer to similar requests which I made to them. I expect one from Maxwell. These four, and one from you if you will write it to me, shall be laid before Mr. Bruce, the minister (" Home Secretary ") who has to make the appointment, and I think should constitute sufficient evidence in support of my brother s application. I thank you very much for your corrections and remarks on our Treatise. Some of the former we had noticed. All will be taken advantage of. I instructed Macmillan to send you a copy of my Electro statics and Magnetism^ which was published just before Christmas. Wishing you and Mrs. Helmholtz " a good new year " as we say in Scotland I remain, yours truly, W. THOMSON. P. S. I am hard at work just now with your cos \// + cr sin \/ + T and trying to help myself by it to find the shape of a coreless cylindrical vortex couple. In this winter of 1872-73 Sir William Thomson sent several technical communications to the newly- founded Society of Telegraph Engineers, of which he was a foundation member and vice-president. These were On a New Form of Joule s Tangent Galvanometer, On the Measurement of Electro static Capacity, Tests of Battery, and On a Tray Battery for the Siphon Recorder. This last invention was a form created by the necessity of providing a constant current for the electromagnet VOL. II E 634 LIFE OF LORD KELVIN CHAP. of the recorder, and consisted of a pile of lead-lined shallow wooden trays about a yard square containing zinc grids and sulphate of copper as a modification of Daniell s well-known type of cell. In the early spring he read several papers to the Edinburgh Royal Society, only the titles of which remain ; also two communications in March to the Institute of Engineers in Scotland, on " Signalling through Cables" (illustrated by a model cable) and "On the Rope-dynamometer." He was also very full of the question of distinguishing lighthouse lights by flashing signals, and on signalling the letters of the Morse code by flags and by waving lights. He contributed to Good Words of March 1873 an article on " Lighthouses of the Future" (see p. 725 below). The appointment in March 1873 of Professor James Thomson, LL.D., to the chair of Engineer ing at Glasgow, as successor to Rankine, was a great joy to his younger brother. In the summer of 1873 the James Thomsons lived in Sir William s College house, and reported to him that the day after he left for Brazil his parrot, " Doctor Redtail," had surprised the household by saying " Sir William Thomson gone to Liverpool." GLASGOW COLLEGE, March 15, 1873. DEAR HELMHOLTZ I have delayed too long writing to thank you for your most valuable letter regarding my brother s qualifications for the chair of Engineering. It must, I am sure, have had more influence in promoting his appointment than almost any other document put into the hands of Mr. Bruce, the Home Secretary. I xv THE "HOOPER" 635 have now the satisfaction of being able to tell you that he has been appointed to the chair. He will remain in Belfast to finish the business of the present session there, and next November will enter on his duties in Glasgow. I hope and fully expect that he will have much more time here for original research than the comparatively inconvenient arrangement of the " Queen s University " allows him in Belfast, and he will find my laboratory a great aid. I hope all goes well with you as to your new laboratory and school of experimental science. Remember me kindly to your wife, and believe me, yours always truly, WILLIAM THOMSON. [-P.^S.] I expect a visit from Joule when my brother comes over in the course of a week or two, to be formally admitted to the chair. He is President-elect of the British Association at the meeting appointed for Brad ford in Sept. next. Is there any chance of your being present? I am sorry that I shall not be able to be there as I am to be away in Brazil laying cables. YACHT LALLA ROOKH, LARGS, May 25, 1873. MY DEAR ANDREWS ... I ought sooner to have written to thank you and Mrs. Andrews for your very kind invitation, but I waited till I could see my way as to a possible time for going across to Belfast. I have had a great deal on hand seeing the new cable-ship Hooper, and sailing round in her on her first voyage from the builder s yard at Newcastle to Millwall Dock, etc., etc. I have now to get sounding apparatus, and one of my laboratory students indoctrinated in the use of it, despatched by a steamer to sail from Liverpool on the 3 ist for Para, and take soundings along the coast of Brazil from Para to Pernambuco. I hope about ten days hence to be able to sail across, and to look after the setting up of an eclipsing arrangement which the Harbour Commissioners have ordered for the light in Holywood bank. If I can manage to remain a night in Belfast it 636 LIFE OF LORD KELVIN CHAP. will be a great pleasure to me to avail myself of your invitation, should the time, which I am sorry is still necessarily uncertain, be convenient to you and Mrs. Andrews. Believe me, yours very truly, W. THOMSON. On April 23 Sir William wrote to Miss Jessie Crum that on the Friday before he had set out on a three days cruise with his nephew W. Bottomley and Dr. James Napier. They saw the Ardrossan harbour light, "an excellent distinguishing light introduced by Mr. Thomas Stevenson." On May 28 he wrote again from London, where the Hooper was taking in cable, that he was returning to Glasgow to sail in the yacht for Liverpool with Mary and Mr. Watson l to see sounding apparatus on a ship. Preparations were now far advanced for the laying of the new cable from Pernambuco to Para. He sent word to his brother : (Post-mark London, S.W., July 16, 1873.) CABLE-SHIP HOOPER, June 15/73. DEAR JAMES . . . The cable-ship came out of dock yesterday, and after about two days here is to sail for Plymouth. It may be Saturday next, or more probably a few days later, that we leave finally for Brazil. Having seen the cable, and arrangements for testing all right, and the ship away from the factory, I leave her to-morrow morning, and after a day and a half in London, leave (I trust) to-morrow afternoon for Cowes, to sail thence west wards. I have a cable (the " Direct Spanish ") to test at Lizard before going away in the Hooper, and I hope to be able to sail there, and possibly further to Porthcurno, 1 Rev. Charles Watson, D.D., who had married Miss Mary Gray Crum. He was Free Church minister at Largs, and died 1908. xv THE "HOOPER" 637 and see trials of my new automatic sender there, and, still sailing in the L. R., get back to Plymouth in time. If wind does not answer I shall have to take train. Your affec te brother, W. T. On Friday, June 2Oth, the Hooper sailed from the Thames, having on board some 2500 miles of cable. On the 26th she landed the shore end at Lisbon, and proceeded westwards with the rest of the cable. " Here we are," wrote Jenkin to his wife from the Hooper, on June 29, " off Madeira at seven o clock in the morning. Thomson has been sounding with his special toy ever since half- past three (1087 fathoms of water)." On July 7th Sir William wrote to his sister-in-law from the Hooper, then lying in Funchal Bay, that they had been there a week and would be there a week more. A few days after leaving Plymouth a fault had been found in the cable in a length of 543 miles that was coiled in one of the three tanks ; and as the fault was 400 miles down the coil they had had a prodigious work in uncoiling, splicing pieces, and recoiling. The expense to Hooper s Company was some ^200 per day ; but it was well that the stoppage had been here, not at Cape Verde or at Pernambuco. He had been struck by the marvellous beauty of the island. "It has been impossible," he added, "to keep off Darwinism, and although Madeira gave Darwin some of his most notable and ingenious illustrations and proofs (!) we find at every turn something to show (if anything were needed to show) the utter futility of his philosophy." 638 LIFE OF LORD KELVIN CHAP. An incident related by R. L. Stevenson in his memoir of Fleeming Jenkin, deserves mention : I shall not readily forget with what emotion he once told me an incident of their associated travels. On one of the mountain ledges of Madeira, Fleeming s pony bolted between Sir William and the precipice above ; by strange good fortune, and thanks to the steadiness of Sir William s horse, no harm was done ; but for the moment, Fleeming saw his friend hurled into the sea, and almost by his own act : it was a memory that haunted him. A month later Thomson wrote a further account of the events of the voyage : Aug. 8, Friday. PLA^A DO COMMERCIO, RECIFE, PERNAMBUCO. We hope to be under weigh for Para, paying out cable from the stern of the Hooper, before dark this evening. . . . I have bought a parrot, green, with splendid red tips to his wing shoulders and end-wing feathers, dark blue outer wing feathers, light blue and white head, brilliant yellow breast. 1 The colouring is as rich and varied as Mrs. Bowden Fullarton s dress, and even more harmonious in general effect . . . Tell Mary that we have had a great deal of dot and dash practice between the Hooper and the Paraense, both by lamps at night and (with far more difficulty) by various other means in the day-time, to be ready to receive her soundings, and tell her where to go next in choosing out track for Para. We had some admirable lamp signalling several evenings at Funchal between the Hooper and Mr. Blandy s house, about i^ miles distant. The Miss Blandys learned " Morse " very well and quickly, and both sent and read long telegrams the first evening they tried it, to the admiration of France and other old tele graphers on board. 1 This parrot, named " Professor Papagaio," lived many years in the College House. When he died he was stuffed, and is now in the Hunterian Museum in Glasgow University. XV THE "HOOPER" 639 The ladies in question were the daughters of Charles R. Blandy, Esq., one of the principal residents of Madeira, at whose villa Sir William was welcomed. The delay to the expedition lasted over a fortnight, but at last the repairs were completed. An eye-witness has recounted how, when the anchor was weighed, and the Hooper steamed slowly out of Funchal Bay, a figure was seen waving a floating streak of white drapery from a window of the house on the hill high above the port. " G-O-O-D-B-Y-E " was spelled out. " Eh ! What s that? What s that?" said Sir William, adjusting his eye-glass the better to catch the signals. " Good -bye, good-bye, Sir William Thomson." And as the ship s hull dipped beyond the horizon the white streak still fluttered " Good bye." CHAPTER XVI IN THE SEVENTIES HOLDING his fellowship at Peterhouse, Sir William Thomson now frequented Cambridge more often ; and on returning from Pernambuco he paid a visit there on his way north. He wrote to his sister, Mrs. King : ST. PETER S COLLEGE, CAMBRIDGE, Oct. 22, 1873. MY DEAR ELIZABETH ... I am here till the 29th, when there is an important College meeting which I should have had to come back from Glasgow to attend if I had been there. Meantime I am very busy, having (in consequence of having been re-elected to a fellowship) accepted the office of " additional examiner " for the Senate-house examination of next January. Making questions and meeting with the other examiners and the moderators is my present occupation. Then in January there will be some days of hard work examining the answers. Since coming here last week I have been again rowing in an eight-oar (the first time since 1 846) with the " ancient mariners," of whom Fawcett, the (blind) member for Brighton, is a chief. David (jun 1 ") 1 has been doing very well indeed. He is not to go out in the Hooper this trip (to lay the Pernambuco- Bahia-Rio Janeiro sections, for w h she leaves the Thames on 3rd of Nov.), but will remain in charge at Millwall. 1 David Thomson King, who was drowned at sea (see p. 655). 640 CH. xvi IN THE SEVENTIES 641 This, I think, will be better for his progress afterwards than going to sea just now would have been, as it makes him known to Mr. Heugh and others as holding a responsible position. He will probably go out on the Para -St. Thomas (a very important part of the work) next spring. I shall try to get him a short holiday soon. I shall be in London from the 3Oth Oct. till the 3rd Nov. to make final arrangements and see the Hooper off. Your affec 6 brother, W. T. In December 1873 Sir William read a paper to the Royal Society of Edinburgh on a new method of determining the material and thermal diffusion of fluids. He wrote on Christmas day from Knowsley to Mrs. King : Yesterday I came here on a visit to Lord and Lady Derby for a few days. On Saturday or Monday I go to Mere Old Hall, near Knutsford, William Crum s place, to remain till the end of the holidays. I have to be at the Royal Society, Edinburgh, on Monday week to " read " a paper, which, however, will not, I fear, be written till after the reading. As Mrs. Johnstone told you, I shall have to be there after this winter, having been elected to be President. My Cambridge work (as one of the examiners l for the " Mathematical Tripos" of 1874) will keep me very busy till the end of January, when it will be over. I have brought the examination papers here (a very large heap) for revisal, etc. About the 2Oth of January I shall have to go there and remain till the list showing the result is given out. A letter to Dr. King followed : 1 As examiner for the Mathematical Tripos Sir William Thomson intro duced various changes to give greater width of studies in the direction of Natural Philosophy. That these reforms did not please all the Cambridge mathematicians was natural ; but Maxwell, who had paved the way for them, rejoiced. 642 LIFE OF LORD KELVIN CHAP. CAMBRIDGE, /#;/. 27/74. MY DEAR DAVID I should have written sooner, if only to say so much ; but that I have been absolutely overwhelmed with ex amination papers (answers to our printed questions) for the " Mathematical Tripos," that is to say, the Cam bridge University examination for mathematical honours. The work is exceedingly interesting to me, but most laborious and wearisomely plodding. For my share of one sitting of the candidates I got io|- Ibs. of papers of written answers. I have had seven such hauls, and scarcely any of them less than 5 Ibs. By the same post with this (or by to-morrow s) I shall send a specimen of our printed papers of questions w h it may interest you to see. The questions marked with roman numerals in it are mine, the " arabic " by another examiner. I shall enclose it in a number of the Telegraphic Journal con taining a report of an " address " I was obliged to make in London on my way here. I had only (after enormous labour with Tatlock in two days) succeeded in getting enough written to occupy 4 MINUTES, and the prospect had made me feel as if I had a millstone round my neck for a fortnight before the day. So after I read the little beginning piece, the rest was a " leap in the dark " altogether. I had really not an idea of what I was going to say, so I was thankful when it was all over. I was sur prised a few days later with a copy of the Telegraphic Journal containing the report, which had been taken (very well as I thought) by a shorthand writer. It seems to contain every word I said, with only a few errors. . . . I would like very much to make a cruise in the Mediterranean, but next May and June I shall in all probability not be free to do so. The Society of Telegraph Engineers, destined later to blossom into the Institution of Electrical Engineers, was then not three years old. Sir XVI IN THE SEVENTIES 643 William Thomson, as its president, in his inaugural address l dealt chiefly with the reflected benefits which science gains from its practical applications, and the benefit of the systems of measurement that grew up out of the requirements of the prac tical telegraphist. Terrestrial magnetism was still, so far as its cause was concerned, a mystery ; so was that of terrestrial electricity. But telegraph engineers, by investigating the facts over the globe, could help to solve these mysteries. He regarded the Telegraph Engineers as a society for establishing harmony between theory and practice in electrical engineering, and in electrical science generally, by organized co-operation. Within a month he gave another presidential address to the Glasgow Geological Society on the Influence of Geological Changes on the Earth s Rotation, and communicated a paper on Deep-sea Sounding. At Edinburgh he read an important paper on the Kinetic Theory of the Dissipation of Energy. On April 10 he took a preliminary cruise of four days on the yacht with a party including Jenkin and some former students. To Charles Abercromby Smith (now Sir Charles), of Cape Town, he wrote : GLASGOW UNIVERSITY, April 28, 1874. MY DEAR SMITH You know by this time that I am again a colleague of yours, as Fellow of Peterhouse. It 1 See The Telegraphic Journal, vol. ii. p. 67, Jan. 15, 1874 ; Soc. of Telegr. Engineers Journal, iii. pp. 1-15, 1874; Pop, Lectures, ii. p. 206. 644 LIFE OF LORD KELVIN CHAP. is pleasant to be again associated with a former pupil and friend, though we are pretty nearly at two extremities of a diameter of the earth. Do you remember Tatlock ? at all events he remembers often hearing about you, and of your thermo-electric experiments in the laboratory of the old College. . . . This is written in his hand. As I have so many engagements, and so much laboratory work that I am kept constantly standing and walking about, I can seldom sit down to write anything, and am obliged to do nearly everything I wish in black and white by dictation. I examined for the mathematical tripos last January, which gave me a good deal of work from about this time last year till the beginning of February, first composing the questions, and then having all the heavy labour of examining the answers. I was at Cambridge in all at different times about five weeks, and enjoyed this very much, as it was very pleasant for me to live once again in the old College, which by the way, as you perhaps know too, has been greatly improved and beautified at much expense. . . . This will be delivered to you by Mr. Coles, who I believe is already known to you. He is, I believe, to disclose to you, and others who may be interested, a new form of cable which has been designed by Hooper s Telegraph Works Company for connecting the Cape with Aden and Mauritius. It is a form of cable in which I have great confidence. The hempen insulation is of the general character which both Professor Jenkin and I have long advocated as being the most suitable for a deep-sea cable, but it is a very great improvement indeed on any thing of this kind that we ever either designed ourselves or have seen designed by others. He was already making plans for the summer. On March 26 he wrote to Froude that he must be in London on 2Oth of April for a soiree of the Tele graph Engineers, and that he intended to sail from Falmouth on 2nd of May for Madeira. The Lalla xvi IN THE SEVENTIES 645 Rookk was ready. He left instructions to have put into his Glasgow house a new heating stove to give next winter a heat " like Madeira," and to procure plants and flowers to decorate it in the autumn, and departed almost gaily for the trip. But this time it was not cable-laying that took him to Madeira. Soon he wrote to Mrs. King, then in Florence : L. /?., FUNCHAL BAY, MADEIRA, Tuesday, May 12, 1874. MY DEAR ELIZABETH I believe you heard from Lizzie that I intended to sail from Falmouth for Madeira on the 2nd of May. The Lalla Rookh has done well taken me to the island, 1200 sea miles from Fal mouth, in 6f days. I anchored exactly at noon on Sunday in Funchal Bay, an hour before the Hooper, which I had left at Greenhithe on Friday week after testing the cable on board, and which sailed from the Thames on the day following. Yesterday I was answered Yes to a question which I asked very soon after the English people came out of forenoon church on Sunday. I was here for sixteen days last June and July on account of a fault in the cable. Otherwise this greatest possible blessing could not have come to me, that is as we see, but surely it is " not chance." When I came to Madeira in the Hooper it had never seemed to me pos sible that such an idea could enter my mind, or that this life could bring me any happiness. I thank God always that I was brought here. When I came away in July I did not think happiness possible for me, and indeed I had not begun even to wish for it. But I carried away an image and impression from which the idea came, and before I landed at Dover in October I had begun to wish for it. Hope grew stronger till yesterday, when I found that I had not hoped in vain. I cannot write more just now, but I send this because I do not wish a mail now on the point of leaving to go without bringing the good news. When you know Fanny you will be 646 LIFE OF LORD KELVIN CHAP. able to really congratulate me. Even now I think you will be glad for my sake. . . . Your ever affectionate brother, WILLIAM THOMSON. The next letter is to Helmholtz : YACHT LALLA ROOKH > FUNCHAL BAY, MADEIRA, June 23, 1874. DEAR HELMHOLTZ I am to be married in Madeira to-morrow. I enclose a photograph, and I hope you will know the original before very long. Let me have a line addressed Athenaeum Club, London, to say if you are to be at the British Association in Belfast. I do not intend to be at the meeting, but if you are to be there we might see you on your way to or from it. We think of sailing from Madeira in the Lalla Rookh about the middle of July, but have not made up our minds whether to make as short a passage as we can to England, or to touch at Gibraltar, Lisbon, Vigo, Corunna, on our way, or to keep a more westerly course and make a little cruise among the Azores. The future mistress of the Lalla Rookh promises to be a very good sailor, having already been out a good many times for a day s sail, one of them round the Desertas (about 70 miles) and always hitherto escaped sea-sickness. Still it remains to be seen whether a yacht cruise on the open Atlantic is a pleasure in direct or in inverse proportion to its duration. My present happiness is due to a fault in the cable which kept the Hooper for sixteen days in Funchal Bay last summer. I hope you and Mrs. Helmholtz and your children are all well. With kind regards, I remain, yours always truly, WILLIAM THOMSON. He wrote the same day a similar letter to Dr. J. Hall Gladstone, adding a congratulation on his election to the Fullerian Professorship of Chemistry at the Royal Institution : " To be Faraday s suc cessor is indeed an honour. I am sure you will find the post most congenial to you." xvi IN THE SEVENTIES 647 The Glasgow Herald of July 4, 1874, contained the following announcement : MARRIAGES. At the British Consular Chapel, Funchal, Madeira, on the 24th ult., Sir WILLIAM THOMSON, Professor of Natural Philosophy in the University of Glasgow, to FRANCES ANNA, daughter of CHARLES R. BLANDY, Esq., of Madeira. To his sister Sir William wrote : ST. ANNA, MADEIRA,/*/// 5, 1874. MY DEAR ELIZABETH On the 24 th we rode away in the afternoon to a place called St. Antonio de Serra, about 4 miles ride from Funchal, and 2000 feet above the sea level. We lived there in a house belonging to an uncle of Fanny s for a few days and then came across to this place. We have been taking rides and walks every day and enjoying to the utmost the beauties of Madeira. On Thursday next we return to Funchal, and remain about 10 days in Mr. Blandy s house before sailing away in the Lalla Rookh. -Your affe c brother, W. T. The homeward voyage in the yacht was shortened, for off Finisterre she broke her main gaff, and finished the voyage under top-sail to Cowes for repairs. Sir William and Lady Thom son paid a hurried visit to London, returning to Cowes for further cruising between engagements in town, which prevented them from going to the British Association at Belfast. Here James Thomson was to be president of the Engineering section, and to him, on August 1 2, Sir William wrote, from the Great Western Hotel, Paddington : 648 LIFE OF LORD KELVIN CHAP. MY DEAR JAMES We left Cowes on Friday to come here on business. I have been overwhelmed with arrears of correspondence reports of recent expeditions. The Hooper is expected home about the 1 8th, and I must be here for some time after that to decide what is to be done with the defective cable which the Hooper brings home (which was to have been laid between Cayenne and Demerara, but is brought back because defective). I don t know how long this may keep me, but it may be that for several weeks yet I must be within call of London. We return to the Lalla Rookh at Cowes to-morrow to remain " at home " in her until we return to London for the Hooper. . . . W. Bottomley tells me you are going to refer to the eclipsing system of distinguishing lighthouses. I trust the one on Holywood Bank will be in action and giving practical proof of the plan. You can scarcely be too strong in expressions, as the NEED for distinction in REAL experience, though sailors and admiralty officials believing honestly that they speak from experience are quite ready to deny it. I think you might refer to the soundings by pianoforte wire. . . . When we get quite free from London we shall prob ably sail for the Clyde, weather and time permitting. We should touch at several places on the way so as to have chiefly sailing by day and resting in port by night. If the Holywood Bank eclipsing light is as I hope it will be, we should probably go into Belfast Lough to look at it on our way, and even without that inducement we might make Belfast one of our ports and take a few hours to run up and see our friends there. You, I suppose, will be back in Glasgow before that time ; but when we get back to the Clyde I hope you will be able to come and have a few days sailing with us. We shall take the earliest opportunity after getting to Scotland to go to the College, and perhaps remain there a few days ; but the yacht will be our headquarters probably till about xvi IN THE SEVENTIES 649 the middle of October. You must take some thorough rest after you get over the B.A. and your address. I am afraid in the meantime you will be too busy to allow you much rest. . . . Your affectionate brother, W. THOMSON. They were not able to attend the British Association, but Sir William communicated two papers : one on Perturbations of the Compass at Sea, and another on his Improvements in Compasses. To Dr. King he sent a message strongly disap proving of Tyndall s famous presidential address, and of the dictum in which he had discerned in matter " the promise and potency of all terrestrial life." Thomson thought it " especially inappro priate." Later they sailed to Belfast, thence to Largs to visit friends and relations ; then went to Glasgow to see "home." After that there was a final cruise to Arran before the session began. On October 29th Sir William wrote to Mrs. King : We have bought a little piece of ground, Kirklands, Largs, bounded on the south and north-west by the Noddle Burn (Noddsdale Burn, properly), on the road to Barr s farm, to build a house on. We shall begin building before very long, I hope. I thought you would be interested to have the earliest news of this. " Netherhall " was the name given to the house, 1 a commodious country mansion in the Scottish baronial style, the building of which occupied many months. Sir William, with the aid of his brother, 1 For a full description of the building, see The Building News, June 27,. 1890. It is there stated that the cost was 12,000. VOL. II F 650 LIFE OF LORD KELVIN CHAP. took a large part in the planning of the building, which was original in many ways. He himself engaged a master-mason and a master-carpenter, instead of letting the contract to a builder a costly and vexatious plan in the sequel. A dozen years later the estate was much improved by the purchase of additional ground. Netherhall was the scene in after years of many family reunions, and of extended hospitalities presided over by the gracious hostess. It was here that Sir William sought quiet hours when the yachting days were over ; and to it he retired when he withdrew from his chair in 1899. Sir William Thomson was now 51 years of age, but, save for his slight lameness, as active as in youth. For nearly thirty years he had never felt the want of money, and for some years past had enjoyed a very large professional income. 1 He was supremely happy in his domestic life. Lady Thomson had been welcomed into the circle of family relations, and directed his household with rare dignity and grace. His academic duties were lightened by the devoted assiduity of his official assistant MacFarlane, and of his demonstrator and deputy-lecturer, James T. Bottomley. A graphic picture of Sir William as he appeared 1 The income of the partnership of Thomson, Varley, and Jenkin was considerable, for they derived handsome profits from their inventions. Varley s patent for the signalling condenser was very profitable. Sir William, writing to Jenkin in 1881, speaks of "the quadrant electrometer, the mirror galvano meter, and the last recorder patent, which is now bringing us ^3000 from the Eastern Telegraph Co., .2100 from the Eastern Extension, and ,1500 from the Anglo." The partnership of Thomson and Jenkin as consulting engineers to various cable companies was also extremely profitable, and brought them each several thousands a year. xvi IN THE SEVENTIES 651 to his students has been recorded by Professor Andrew Gray, then one of the merry students who filled the ten benches of the lecture theatre, after wards his trusted secretary and scientific assistant, and finally his successor in the chair of Natural Philosophy. By his kind permission * the following extracts are given from his admirable book : The writer will never forget the lecture-room when he first beheld it, from his place on Bench VIIL, a few days after the beginning of session 1874-75. Sir William Thomson, with activity emphasised rather than otherwise by his lameness, came in with the students, passed behind the table, and, putting up his eye-glass, surveyed the apparatus set out. Then, as the students poured in, an increasing stream, the alarm weight was released by the bell-ringer, and fell slowly some four or five feet from the top of the clock to a platform below. By the time the weight had descended the students were in their places, and then, as Thomson advanced to the table, all rose to their feet, and he recited the third Collect from the Morning Service of the Church of England. It was the custom then, and it is still one better honoured in the observance than in the breach (which has become rather common), to open all the first and second classes of the day with prayer ; and the selection of the prayers was left to the discretion of the professors. Next came the roll- call by the assistant ; each name was called in its English or Scottish (for the clans were always well represented) form, and the answer " adsum " was returned. The vivacity and enthusiasm of the Professor at that time was very great. The animation of his countenance as he looked at a gyrostat spinning, standing on a knife-edge or on a glass plate in front of him, and leaning over so that its centre of gravity was on one side of the point of support ; the delight with which he showed that hurrying of the precessional motion caused the gyrostat to rise, and retarding the precessional motion caused the gyrostat to fall, so that the freedom to " precess " was the secret of its not falling ; the immediate application of the study of the gyrostat to the explanation of the precession of the equinoxes, and illustration by a model of a terrestrial globe, arranged so 1 English Men of Science. Lord Kelvin, an Account of his Scientific Life and Work. By Andrew Gray, LL.D., F.R.S., V.-P.R.S.E. London, J. M. Dent and Co., 1908. 652 LIFE OF LORD KELVIN CHAP. that the centre should be a fixed point, while its axis a material spike of brass rolled round a horizontal circle, the centre of which represented the pole of the ecliptic, and the diameter of which subtended an angle at the centre of the globe of twice the obliquity of the ecliptic ; the pleasure with which he pointed to the motion of the equinoctial points along a circle surrounding the globe on a level with its centre, and representing the plane of the ecliptic, and the smile with which he announced, when the axis had rolled once round the circle, that 26,000 years had elapsed all these delighted his hearers, and made the lecture memorable. Then the gyrostat, mounted with its axis vertical on trunnions on a level with the fly-wheel, and resting on a wooden frame carried about by the Professor ! The delight of the students with the quiescence of the gyrostat when the frame, gyrostat and all, was carried round in the direction of the spin of the fly wheel, and its sudden turning upside down when the frame was carried round the other way, was extreme, and when he suggested that a gyrostat might be concealed on a tray of glasses carried by a waiter their appreciation of what would happen was shown by laughter and a tumult of applause. On one occasion, after working out part of a calculation on the long fixed blackboard on the wall behind the table, his chalk gave out, and he dropped his hand down to the long ledge which projected from the bottom of the board to find another piece. None was there, and he had to walk a step or two to obtain one. So he enjoined MacFarlane, his assistant, who was always in attendance, to have a sufficient number of pieces on the ledge in f