"On Sat.u.r.day, May 13th, 1826, I went to London on the way to Dolcoath, and received four chronometers from the Royal Observatory, Greenwich. I travelled by Devonport and Falmouth to Camborne, where I arrived on May 20th and dined at the count-house dinner at the mine. I was accompanied by Ibbotson, who was engaged as a pupil, and intended for an engineer. On May 24th Whewell arrived, and we took a pendulum and clock down, and on the 30th commenced the observation of coincidences in earnest. This work, with the changing of the pendulums, and sundry short expeditions, occupied nearly three weeks. We had continued the computation of our observations at every possible interval. It is to be understood that we had one detached pendulum swinging in front of a clock pendulum above, and another similarly mounted below; and that the clocks were compared by chronometers compared above, carried down and compared, compared before leaving, and brought up and compared. The upper and lower pendulums had been interchanged. It was found now that the reliance on the steadiness of the chronometers was too great; and a new method was devised, in which for each series the chronometers should make four journeys and have four comparisons above and two below. This arrangement commenced on the 19th June and continued till the 20th. On the 26th we packed the lower instruments, intending to compare the pendulum directly with the upper one, and sent them up the shaft: when an inexplicable occurrence stopped all proceedings. The basket containing all the important instruments was brought up to the surface (in my presence) on fire; some of the instruments had fallen out with their cases burning. Whether a superst.i.tious miner had intentionally fired it, or whether the snuff of a candle had been thrown into it, is not known. Our labour was now rendered useless. On the 28th I packed up what remained of instruments, left for Truro, and arrived at Bury on July 1st. During our stay in Cornwall I had attended a 'ticketing'

or sale of ore at Camborne, and we had made expeditions to the N.W. Coast, to Portreath and Illogan, to Marazion and St Michael's Mount, and to Penzance and the Land's End. On July 3rd I saw Mr Cropley in Bury gaol, and went to Cambridge. On the 4th I was admitted A.M., and on the 5th was admitted Major Fellow.

"I had engaged with four pupils to go to Orleans in this Long Vacation: my brother William was also to go. One of my pupils, Dobbs, did not join: the other three were Tinkler, Ogilby, and Ibbotson. We left London on July 9th, and travelled by Brighton, Dieppe, Rouen, and Paris to Orleans. At Paris I saw Bouvard, Pouillet, Laplace and Arago. I had introductions from Mr Peac.o.c.k, Mr South, Mr Herschel, Dr Young; and from Professor Sedgwick to an English resident, Mr Underwood. On the 19th I was established in the house of M. Lagarde, Protestant Minister. Here I received my pupils. On the 28th I commenced Italian with an Italian master: perhaps I might have done more prudently in adhering to French, for I made no great progress. On Aug. 2nd I saw a murderer guillotined in the Place Martroi. The princ.i.p.al investigations on my quires are--Investigations about pendulums, Calculus of Variations, Notes for the Figure of the Earth (Encyc. Metrop.) and commencement of the article, steam-engine machinery, &c. I picked up various French ballads, read various books, got copies of the Ma.r.s.eillaise (this I was obliged to obtain rather secretly, as the legitimist power under Charles X. was then at its height) and other music, and particulars of farm wages for Whewell and R. Jones. The summer was intensely hot, and I believe that the heat and the work in Dolcoath had weakened me a good deal. The family was the old clergyman, his wife, his daughter, and finally his son. We lived together very amicably. My brother lodged in a Cafe in the Place Martroi; the others in different families. I left Orleans on Sept. 30th for Paris. Here I attended the Inst.i.tut, and was present at one of Ampere's Lectures. I arrived at Cambridge on Oct. 14th.

"On Oct. 16th Whewell mentioned to me that the Lucasian Professorship would be immediately vacated by Turton, and encouraged me to compete for it. Shortly afterwards Mr Higman mentioned the Professorship, and Joshua King (of Queens') spoke on the restriction which prevented College tutors or a.s.sistant tutors from holding the office. About this time Mr Peac.o.c.k rendered me a very important service. As the emolument of the Lucasian Professorship was only _99_, and that of the a.s.sistant Tutorship _150_, I had determined to withdraw from the candidature. But Mr Peac.o.c.k represented to me the advantage of position which would be gained by obtaining the Professorship (which I then instantly saw), and I continued to be a candidate. I wrote letters to the Heads of Colleges (the electors) and canva.s.sed them personally. Only Dr Davy, the Master of Caius College, at once promised me his vote. Dr French, Master of Jesus College, was a candidate; and several of the Heads had promised him their votes. Mr Babbage, the third candidate, threatened legal proceedings, and Dr French withdrew. The course was now open for Mr Babbage and me.

"In the meetings of the Philosophical Society a new mode of proceeding was introduced this term. To enliven the meetings, private members were requested to give oral lectures. Mine was the second, I think, and I took for subject The Machinery of the Steam Engines in the Cornish mines, and especially of the Pumping Engines and Pumps. It made an excellent lecture: the subjects were at that time undescribed in books, and unknown to engineers in general out of Cornwall.

"My College lectures seem to have been, Oct. 21st to Dec. 14th to 31 Junior Sophs, Dec. 4th to 12th to 12 Senior Sophs. I a.s.sisted at the examinations of the Questionists. I had no private pupils. On Nov. 26th I communicated to the Cambridge Philosophical Society a Paper on the Theory of Pendulums, Balances, and Escapements: and I find applications of Babbage's symbolism to an escapement which I proposed. I have various investigations about the Earth, supposed to project at middle lat.i.tudes above the elliptical form. In November an account of the Dolcoath failure (by Whewell) was given to the Royal Society.

"At length on Dec. 7th, 1826, the election to the Lucasian Professorship took place: I was elected (I think unanimously) and admitted. I believe that this gave great satisfaction to the University in general. My uncle, Arthur Biddell, was in Cambridge on that evening, and was the first of my friends who heard of it. On the same page of my quires on which this is mentioned, there is a great list of apparatus to be constructed for Lucasian Lectures, notes of experiments with Atwood's Machine, &c. In December, correspondence with Dollond about prisms. I immediately issued a printed notice that I would give professorial lectures in the next Term.

"On Dec. 13th I have a letter from Mr Smith informing me of the dangerous illness (fever) which had attacked nearly every member of his family, Richarda worst of all. On Dec. 23rd I went to Bury. The affairs with Cropley had been settled by the sale of his property under execution, and my father did not lose much of his debt. But he had declined much in body and mind, and now had strange hallucinations.

"The commencement of 1827 found me in a better position (not in money but in prospects) than I had before stood in: yet it was far from satisfactory. I had resigned my a.s.sistant Tutorship of _150_ per annum together with the prospect of succeeding to a Tutorship, and gained only the Lucasian Professorship of _99_ per annum. I had a great aversion to entering the Church: and my lay fellowship would expire in 7 years. My prospects in the law or other professions might have been good if I could have waited: but then I must have been in a state of starvation probably for many years, and marriage would have been out of the question: I much preferred a moderate income in no long time, and I am sure that in this I judged rightly for my happiness. I had now in some measure taken science as my line (though not irrevocably), and I thought it best to work it well, for a time at least, and wait for accidents.

"The acceptance of the Lucasian Professorship prevented me from being pressed by Sedgwick (who was Proctor this year) to take the office of moderator: which was a great relief to me. As Lucasian Professor I was ipso facto Member of the Board of Longitude. A stipend of _100_ a year was attached to this, on condition of attending four meetings: but I had good reason (from intimations by South and other persons in London) for believing that this would not last long. The fortnightly notices of the meetings of the Board were given on Jan. 18th, Mar. 22nd, May 24th and Oct. 18th.

"On Jan. 2nd, 1827, I came from London to Bury. I found my father in a very declining state (the painful rheumatism of some years had changed to ulcerations of the legs, and he was otherwise helpless and had distressing hallucinations). On Jan. 8th I walked to Cambridge. At both places I was occupied in preparations for the Smith's Prize Examination and for lectures (for the latter I obtained at Bury gaol some numerical results about tread-mills).

"Of the Smith's Prize I was officially an Examiner: and I determined to begin with---what had never been done before--making the examination public, by printing the papers of questions. The Prize is the highest Mathematical honour in the University: the compet.i.tors are incepting Bachelors of Arts after the examination for that Degree. My day of examination (apparently) was Jan. 21st. The candidates were Turner, Cankrein, Cleasby, and Mr Gordon. The first three had been my private pupils: Mr Gordon was a Fellow-commoner of St Peter's College, and had just pa.s.sed the B.A. examination as Senior Wrangler, Turner being second. My situation as Examiner was rather a delicate one, and the more so as, when I came to examine the papers of answers, Turner appeared distinctly the first. Late at night I carried the papers to Whewell's rooms, and he on inspection agreed with me. The other examiners (Professors Lax and Woodhouse, Lowndean and Plumian Professors) generally supported me: and Turner had the honour of First Smith's Prize.

"On Jan. 30th my mother wrote, asking if I could see Cropley in London, where he was imprisoned for contempt of Chancery. I attended the meeting of the Board of Longitude on Feb. 1st, and afterwards visited Cropley in the Fleet Prison. He died there, some time later. It was by the sale of his effects under execution that my father's debt was paid.

"On Feb. 15th I communicated to the Royal Society a Paper on the correction of the Solar Tables from South's observations. I believe that I had alluded to this at the February meeting of the Board of Longitude, and that in consequence Mr Pond, the Astronomer Royal, had been requested to prepare the errors of the Sun's place from the Greenwich observations: which were supplied some months later. With the exception of South's Solar Errors, and some investigations about dipping-needles, I do not find anything going on but matters connected with my approaching lectures. There are bridges, trusses, and other mechanical matters, theoretical and practical, without end. Several tradesmen in Cambridge and London were well employed. On Feb. 13th I have a letter from Cubitt about groins: I remember studying those of the Custom-house and other places. On Feb. 20th my Syllabus of Lectures was finished: this in subsequent years was greatly improved. I applied to the Royal Society for the loan of Huyghens's object-gla.s.s, but they declined to lend it. About this time I find observations of the spectrum of Sirius.

"There had been no lectures on Experimental Philosophy (Mechanics, Hydrostatics, Optics) for many years. The University in general, I believe, looked with great satisfaction to my vigorous beginning: still there was considerable difficulty about it. There was no understood term for the Lectures: no understood hour of the day: no understood lecture room. I began this year in the Lent Term, but in all subsequent years I took the Easter Term, mainly for the chance of sunlight for the optical experiments, which I soon made important. I could get no room but a private or retiring room (not a regular lecture room) in the buildings at the old Botanic Garden: in following years I had the room under the University Library. The Lectures commenced on some day in February 1827: I think that the number who attended them was about 64. I remember very well that the matter which I had prepared as an Introductory Lecture did not last above half the time that I had expected, but I managed very well to fill up the hour. On another occasion I was so ill-prepared that I had contemplated giving notice that I was unable to complete the hour's lecture, but I saw in the front row some strangers, introduced by some of my regular attendants, very busy in taking notes, and as it was evident that a break-down now would not do, I silently exerted myself to think of something, and made a very good lecture.

"On Mar. 1st, as official examiner, I received notices from 14 candidates for Bell's Scholarships, and prepared my Paper of questions. I do not remember my day of examination; but I had all the answers to all the examiners' questions in my hands, when on Mar. 27th I received notice that my father had died the preceding evening. This stopped my Lectures: they were concluded in the next term. I think that I had only Mechanics and imperfect Optics this term, no Hydrostatics; and that the resumed Lectures were princ.i.p.ally Optical. They terminated about May 14th.

"With my brother I at once went to Bury to attend my father's funeral. He was buried on Mar. 31st, 1827, in the churchyard of Little Whelnetham, on the north side of the church. Shortly afterwards I went to London, and on Apr. 5th I attended a meeting of the Board of Longitude, at which Herschel produced a Paper regarding improvements of the Nautical Almanac. Herschel and I were in fact the leaders of the reforming party in the Board of Longitude: Dr Young the Secretary resisted change as much as possible. After the meeting I went to Cambridge. I find then calculations of achromatic eye-pieces for a very nice model with silk threads of various colours which I made with my own hands for my optical lectures.

"On Apr. 7th Herschel wrote to me that the Professorship held by Dr Brinkley (then appointed Bishop of Cloyne) at Dublin would be vacant, and recommended it to my notice, and sent me some introductions. I reached Dublin on Apr. 15th, where I was received with great kindness by Dr Brinkley and Dr MacDonnell (afterwards Provost). I there met the then Provost Dr Bartholomew Lloyd, Dr Lardner, Mr Hamilton (afterwards Sir W. R. Hamilton) and others. In a few days I found that they greatly desired to appoint Hamilton if possible (they did in fact overcome some difficulties and appoint him in a few months), and that they would not make such an augmentation as would induce me to offer myself as a candidate, and I withdrew. I have always remembered with grat.i.tude Dr MacDonnell's conduct, in carefully putting me on a fair footing in this matter. I returned by Holyhead, and arrived at Birmingham on Apr. 23rd. While waiting there and looking over some papers relating to the spherical aberration of eye-pieces, in which I had been stopped some time by a geometrical difficulty, I did in the coffee-room of a hotel overcome the difficulty; and this was the foundation of a capital paper on the Spherical Aberration of Eye-pieces. This paper was afterwards presented to the Cambridge Philosophical Society.

"About this time a circ.u.mstance occurred of a disagreeable nature, which however did not much disconcert me. Mr Ivory, who had a good many years before made himself favourably known as a mathematician, especially by his acquaintance with Laplace's peculiar a.n.a.lysis, had adopted (as not unfrequently happens) some singular hydrostatical theories. In my last Paper on the Figure of the Earth, I had said that I could not receive one of his equations. In the Philosophical Magazine of May he attacked me for this with great heat. On May 8th I wrote an answer, and I think it soon became known that I was not to be attacked with impunity.

"Long before this time there had been some proposal about an excursion to the Lake District with my sister, and I now arranged to carry it out. On May 23rd I went to Bury and on to Playford: while there I sketched the c.u.mberland excursion. On June 5th I went to London, I believe to the Visitation of the Greenwich Observatory to which I was invited. I also attended the meeting of the Board of Longitude. I think it was here that Pond's Errors of the Sun's place in the Nautical Almanac from Greenwich Observations were produced. On June 7th I went by coach to Rugby, where I met my sister, and we travelled to Edensor. We made a number of excursions in Derbyshire, and then pa.s.sed on by Penrith to Keswick, where we arrived on June 22nd. From Keswick we made many excursions in the Lake District, visited Mr Southey and Mr Wordsworth, descended a coal mine at Whitehaven, and returned to Edensor by the way of Ambleside, Kendal, and Manchester.

With sundry excursions in Derbyshire our trip ended, and we returned to Cambridge on the 21st July.

"During this Long Vacation I had one private pupil, Crawford, the only pupil this year, and the last that I ever had. At this time there is on my papers an infinity of optical investigations: also a plan of an eye-piece with a concave lens to destroy certain aberrations. On Aug. 20th I went to Woodford to see Messrs Gilbert's optical works. From Aug. 13th I had been preparing for the discussion of the Greenwich Solar Errors, and I had a man at work in my rooms, engaged on the calculation of the Errors. I wrote to Bouvard at Paris for observations of the sun, but he recommended me to wait for the Tables which Bessel was preparing. I was busy too about my Lectures: on Sept. 29th I have a set of plans of printing presses from Hansard the printer (who in a visit to Cambridge had found me making enquiries about them), and I corresponded with Messrs Gilbert about optical constructions, and with W. and S. Jones, Eastons, and others about pumps, hydraulic rams, &c. On Sept. 25th occurred a very magnificent Aurora Borealis.

"I do not find when the investigation of Corrections of Solar Elements was finished, or when my Extracts from Burckhardt, Connaissance des Temps 1816, were made. But these led me to suspect an unknown inequality in the Sun's motion. On Sept. 27th and 28th I find the first suspicions of an inequality depending on 8 mean longitude of Venus--13 mean longitude of Earth. The thing appeared so promising that I commenced the investigation of the perturbation related to this term, and continued it (a very laborious work) as fast as I was able, though with various interruptions, which in fact were necessary to keep up my spirits. On Oct. 30th I went to London for the Board of Longitude meeting. Here I exhibited the results of my Sun investigations, and urged the correction of the elements used in the Nautical Almanac. Dr Young objected, and proposed that Bouvard should be consulted. Professor Woodhouse, the Plumian Professor, was present, and behaved so captiously that some members met afterwards to consider how order could be maintained. I believe it was during this visit to London that I took measures of Hammersmith Suspension Bridge for an intended Lecture-model. Frequently, but not always, when in London, I resided at the house of Mr Sheepshanks and his sister Miss Sheepshanks, 30 Woburn Place. My quires, at this time, abound with suggestions for lectures and examinations.

"On some day about the end of November or beginning of December 1827, when I was walking with Mr Peac.o.c.k near the outside gate of the Trinity Walks, on some mention of Woodhouse, the Plumian Professor, Mr Peac.o.c.k said that he was never likely to rise into activity again (or using some expression importing mortal illness). Instantly there had pa.s.sed through my mind the certainty of my succeeding him, the good position in which I stood towards the University, the probability of that position being improved by improved lectures, &c., &c., and by increased reputation from the matters in which I was now engaged, the power of thus commanding an increase of income. I should then have, independent of my Fellowship, some competent income, and a house over my head. I was quite aware that some time might elapse, but now for the first time I saw my way clearly. The care of the Observatory had been for two or three years attached to the Plumian Professorship. A Grace was immediately prepared, entrusting the temporary care of the Observatory to Dr French, to me, Mr Catton, Mr Sheepshanks, and Mr King (afterwards Master of Queens' College). On Dec. 6th I have a note from Mr King about going to the Observatory.

"On Dec. 6th my Paper on corrections of the elements of the Solar Tables was presented to the Royal Society. On Dec. 9th, at 1 h. 4 m. a.m. (Sunday morning), I arrived at the result of my calculations of the new inequality. I had gone through some fluctuations of feeling. Usually the important part of an inequality of this kind depends entirely on the eccentricities of the orbits, but it so happened that from the positions of the axes of the orbits, &c., these terms very nearly destroyed each other. After this came the consideration of inclinations of orbits; and here were sensible terms which were not destroyed. Finally I arrived at the result that the inequality would be about 3"; just such a magnitude as was required. I slipped this into Whewell's door. This is, to the time of writing (1853), the last improvement of any importance in the Solar Theory. Some little remaining work went on to Dec. 14th, and then, being thoroughly tired, I laid by the work for revision at some future time. I however added a Postscript to my Royal Society Paper on Solar Errors, notifying this result.

"On Dec. 19th I went to Bury. While there I heard from Whewell that Woodhouse was dead. I returned to Cambridge and immediately made known that I was a candidate for the now vacant Plumian Professorship. Of miscellaneous scientific business, I find that on Oct. 13th Professor Barlow of Woolwich prepared a memorial to the Board of Longitude concerning his fluid telescope (which I had seen at Woodford), which was considered on Nov. 1st, and I had some correspondence with him in December. In June and August my Trigonometry was printing.

"On Jan. 5th, 1828, I came from London. It seems that I had been speculating truly 'without book' on perturbations of planetary elements, for on Jan. 17th and 18th I wrote a Paper on a supposed error of Laplace, and just at the end I discovered that he was quite right: I folded up the Paper and marked it 'A Lesson.' I set two papers of questions for Smith's Prizes (there being a deficiency of one Examiner, viz. the Plumian Professor).

"Before the beginning of 1828 Whewell and I had determined on repeating the Dolcoath experiments. On Jan. 8th I have a letter from Davies Gilbert (then President of the Royal Society) congratulating me upon the Solar Theory, and alluding to our intended summer's visit to Cornwall. We had somehow applied to the Board of Longitude for pendulums, but Dr Young wished to delay them, having with Capt. Basil Hall concocted a scheme for making Lieut. Foster do all the work: Whewell and I were indignant at this, and no more was said about it. On Jan. 24th Dr Young, in giving notice of the Board of Longitude meeting, informs me that the clocks and pendulums are ready.

"I had made known that I was a candidate for the Plumian Professorship, and n.o.body thought it worth while to oppose me. One person at least (Earnshaw) had intended to compete, but he called on me to make certain that I was a candidate, and immediately withdrew. I went on in quality of Syndic for the care of the Observatory, ingrafting myself into it. But meantime I told everybody that the salary (about _300_) was not sufficient for me; and on Jan. 20th I drafted a manifesto or application to the University for an increase of salary. The day of election to the Professorship was Feb. 6th. As I was officially (as Lucasian Professor) an elector, I was present, and I explained to the electors that I could not undertake the responsibility of the Observatory without augmentation of income, and that I requested their express sanction to my application to the University for that purpose. They agreed to this generally, and I was elected. I went to London immediately to attend a meeting of the Board of Longitude and returned on Feb. 8th. On Feb. 15th I began my Lectures (which, this year, included Mechanics, Optics, Pneumatics, and Hydrostatics) in the room below the University Library. The number of names was 26. The Lectures terminated on Mar. 22nd.

"On Feb. 25th I received from Mr Pond information on the emoluments at Greenwich Observatory. I drew up a second manifesto, and on Feb. 26th I wrote and signed a formal copy for the Plumian electors. On Feb. 27th I met them at Caius Lodge (the Master, Dr Davy, being Vice-Chancellor). I read my Paper, which was approved, and their sanction was given in the form of a request to the Vice-Chancellor to permit the paper to be printed and circulated. My paper, with this request at the head, was immediately printed, and a copy was sent to every resident M.A. (more than 200 went out in one day). The statement and composition of the paper were generally approved, but the University had never before been taken by storm in such a manner, and there was some commotion about it. I believe that very few persons would have taken the same step. Mr Sheepshanks wrote to me on Mar. 7th, intimating that it was desperate. I had no doubt of success. Whewell told me that some people accused me of bad faith, in omitting allusion to the _100_ a year received as Member of the Board of Longitude, and to the profits of Lectures. I wrote him a note, telling him that I had most certain information of the intention to dissolve the Board of Longitude (which was done in less than six months), and that by two years' Lectures I had gained _45_ (the expenses being _200_, receipts _245_). This letter was sent to the complaining people, and no more was said. By the activity of Sheepshanks and the kindness of Dr Davy the business gradually grew into shape, and on Mar. 21st a Grace pa.s.sed the Senate for appointing a Syndicate to consider of augmentation. Sheepshanks was one of the Syndicate, and was understood to represent, in some measure, my interests. The progress of the Syndicate however was by no means a straightforward one. Members of the Senate soon began to remark that before giving anything they ought to know the amount of the University revenue, and another Syndicate was then appointed to enquire and report upon it. It was more than a year before my Syndicate could make their recommendation: however, in fact, I lost nothing by that delay, as I was rising in the estimation of the University. The Observatory house was furnished, partly from Woodhouse's sale, and partly from new furniture. My mother and sister came to live with me there. On Mar. 15th 1828 I began the Observatory Journal; on Mar. 27th I slept at the Observatory for the first time, and on Apr. 15th I came to reside there permanently, and gave up my college rooms."

CHAPTER IV.

AT CAMBRIDGE OBSERVATORY. FROM HIS TAKING CHARGE OF THE CAMBRIDGE OBSERVATORY TO HIS RESIDENCE AT GREENWICH OBSERVATORY AS ASTRONOMER ROYAL.

FROM MARCH 15TH 1828 TO JAN. 1ST 1836.

1828

"I attended a meeting of the Board of Longitude on Apr. 3rd. And again on June 4th; this was the last meeting: Sheepshanks had previously given me private information of the certainty of its dissolution.--On Apr. 4th I visited Mr Herschel at Slough, where one evening I saw Saturn with his 20-foot telescope, the best view of it that I have ever had.--In June I attended the Greenwich Observatory Visitation.--Before my election (as Plumian Professor) there are various schemes on my quires for computation of transit corrections, &c. After Apr. 15th there are corrections for deficient wires, inequality of pivots, &c. And I began a book of proposed regulations for observations. In this are plans for groups of stars for R.A. (the Transit Instrument being the only one finished): order of preference of cla.s.ses of observations: no reductions to be made after dinner, or on Sunday: no loose papers: observations to be stopped if reductions are two months in arrear: stars selected for parallax.--The reduction of transits begins on Apr. 15th. On May 15th Mr Pond sent me some moon-transits to aid in determining my longitude.--Dr Young, in a letter to me of May 7th, enquires whether I will accept a free admission to the Royal Society, which I declined. On May 9th I was elected to the Astronomical Society.--Towards the end of the year I observed Encke's Comet: and determined the lat.i.tude of the Observatory with Sheepshanks's repeating circle.--On my papers I find a sketch of an Article on the Figure of the Earth for the Encyclopaedia Metropolitana.

"As early as Feb. 23rd I had been in correspondence with T. Jones, the instrument-maker, about pendulums for a repet.i.tion of the Dolcoath Experiments. Invitations had been received, and everything was arranged with Whewell. Sheepshanks, my brother, and Mr Jackson of Ipswich (Caius Coll.) were to go, and we were subsequently joined by Sedgwick, and Lodge (Magdalene Coll.). On July 3rd Sheepshanks and I started by Salisbury, taking Sherborne on our way to look at the church, which had alarmed the people by signs of a crack, and arrived at Camborne on July 8th. On the 14th we set up the pendulums, and at once commenced observations, our plan being, to have no intermission in the pendulum observations, so that as soon as the arc became too small a fresh series was started. On July 29th we raised the instruments, and Sheepshanks, who managed much of the upper operations, both astronomical and of pendulums, mounted the pendulums together in his observatory. We went on with our calculations, and on August 8th, on returning from a visit to John Williams at Barncoose, we heard that there was a 'run' in Dolcoath, that is a sinking of the whole ma.s.s of rock where it had been set free by the mine excavations: probably only a few inches, but enough to break the rock much and to stop the pumps. On Aug. 10th the calculations of our observations shewed that there was something wrong, and on the 13th I perceived an anomaly in the form of the knife edge of one pendulum, and of its agate planes, and suggested cautions for repeating the observations.

We determined at once to repeat them: and as the water was rising in the mine there was no time to be lost. We again sent the instruments down, and made observations on the 16th, 17th and 18th. On the 19th I sent the instruments up, for the water was near our station, and Sedgwick, Whewell, and I went on a geological expedition to the Lizard. On our return we met Sheepshanks and the others, and found the results of the last observations unsatisfactory. The results of comparing the pendulums were discordant, and the knife edge of the faulty pendulum had very sensibly altered. We now gave up observations, with the feeling that our time had been totally lost, mainly through the fault of the maker of the pendulum (T. Jones). On the 28th we made an expedition to Penzance and other places, and arrived at Cambridge on the 17th of September.

"In the course of the work at Dolcoath we made various expeditions as opportunity offered. Thus we walked to Carn Brea and witnessed the wrestling, the common game of the country. On another occasion Sedgwick, Whewell, and I had a capital geological expedition to Trewavas Head to examine granite veins. We visited at Pendarves and Trevince, and made the expedition to the Lizard already referred to, and saw many of the sights in the neighbourhood. After visiting Penzance on the conclusion of our work we saw Cape Cornwall (where Whewell overturned me in a gig), and returned homewards by way of Truro, Plymouth (where we saw the watering-place and breakwater: also the Dockyard, and descended in one of the working diving-bells), Exeter, Salisbury, and Portsmouth. In returning from Camborne in 1826 I lost the princ.i.p.al of our papers. It was an odd thing that, in going through Exeter on our way to Camborne in 1828, I found them complete at Exeter, identified to the custodian by the dropping out of a letter with my address.

"On my return to Cambridge I was immediately immersed in the work of the Observatory. The only instrument then mounted at the Observatory was the Transit. I had no a.s.sistant whatever.--A Mr Galbraith of Edinburgh had questioned something in one of my Papers about the Figure of the Earth. I drew up a rather formal answer to it: Whewell saw my draft and drew up a much more pithy one, which I adopted and sent to the Philosophical Magazine.--For comparing our clocks at the upper and lower stations of Dolcoath we had borrowed from the Royal Observatory, Greenwich, six good pocket chronometers: they were still in the care of Mr Sheepshanks. I arranged with him that they should be sent backwards and forwards a few times for determining the longitude of Cambridge Observatory. This was done on Oct. 21st, 22nd, 23rd: the result was 2354, and this has been used to the present time (1853). It evinced an error in the Trigonometrical Survey, the origin of which was found, I think, afterwards (Dr Pearson in a letter of Dec. 17th spoke of the mistake of a may-pole for a signal-staff). I drew up a Paper on this, and gave it to the Cambridge Philosophical Society on Nov. 24th. (My only academical Paper this year.)--I had several letters from Dr Young, partly supplying me with calculations that I wanted, partly on reform or extension of the Nautical Almanac (which Dr Young resisted as much as possible). He considered me very unfairly treated in the dissolution of the Board of Longitude: Professor Lax wished me to join in some effort for its restoration, but I declined.

"As my reduction of observations was kept quite close, I now began to think of printing. In regard to the form I determined to adopt a plan totally different from that of any other observations which I had seen. The results were to be the important things: I was desirous of suppressing the separate wires of transits. But upon consulting Herschel and other persons they would not agree to it, and I a.s.sented to keeping them. I applied to the Press Syndicate to print the work, and on Nov. 10th at the request of T. Musgrave (afterwards Archbishop of York) I sent a specimen of my MS.: on Nov. 11th they granted 250 copies, and the printing soon commenced."

1829

"During a winter holiday at Playford I wrote out some investigations about the orbits of comets, and on Jan. 23rd 1829 I returned to Cambridge. The Smith's Prize Examination soon followed, in which I set a Paper of questions as usual. On Feb. 18th I made notes on Liesganig's geodetic work at the British Museum.

"I was naturally anxious now about the settlement of my salary and of the Observatory establishment. I do not know when the Syndicate made their Report, but it must have been in the last term of 1828. It recommended that the salary should be annually made up (by Grace) to _500_: that an a.s.sistant should be appointed with the a.s.sent of the Vice-Chancellor and dismissable by the Plumian Professor: and that a Visiting Syndicate should be appointed, partly official and partly of persons to be named every year by Grace. The Grace for adopting this Report was to be offered to the Senate on Feb. 27th. The pa.s.sing of the Grace was exposed to two considerable perils. First, I found out (just in time) that a Senior Fellow of Trinity (G.A. Browne) was determined to oppose the whole, on account of the insignificant clause regarding dismissal of a.s.sistants, which he regarded as tyrannical. I at once undertook that that clause should be rejected. Secondly, by the absurd const.i.tution of the 'Caput' at Cambridge, a single M.A. had the power of stopping any business whatever, and an M.A. actually came to the Senate House with the intention of throwing out all the Graces on various business that day presented to the Senate. Luckily he mistook the hour, and came at 11 instead of 10, and found that all were dispatched. The important parts of the Grace pa.s.sed without any opposition: but I mustered some friends who negatived that part which had alarmed G.A. Browne, and it was corrected to his satisfaction by a new Grace on Mar. 18th. I was now almost set at rest on one of the great objects of my life: but not quite. I did not regard, and I determined not to regard, the addition to my salary as absolutely certain until a payment had been actually made to me: and I carefully abstained, for the present, from taking any steps based upon it. I found for a.s.sistant at the Observatory an old Lieutenant of the Royal Navy, Mr Baldrey, who came on Mar. 16.

"On May 4th I began lectures: there were 32 names. The Lectures were improving, especially in the optical part. I do not find note of the day of termination.--I do not know the actual day of publication of my first small volume of Cambridge Observations, 1828, and of circulation. The date of the preface is Apr. 27th 1829. I have letters of approval of it from Davies Gilbert, Rigaud, and Lax. The system which I endeavoured to introduce into printed astronomical observations was partially introduced into this volume, and was steadily improved in subsequent volumes. I think that I am justified, by letters and other remarks, in believing that this introduction of an orderly system of exhibition, not merely of observations but of the steps for bringing them to a practical result--quite a novelty in astronomical publications--had a markedly good effect on European astronomy in general.--In Feb. and March I have letters from Young about the Nautical Almanac: he was unwilling to make any great change, but glad to receive any small a.s.sistance. South, who had been keeping up a series of attacks on Young, wrote to me to enquire how I stood in engagements of a.s.sistance to Young: I replied that I should a.s.sist Young whenever he asked me, and that I disapproved of South's course.--The date of the first visitation of the (Cambridge) Observatory must have been near May 11th: I invited South and Baily to my house; South and I were very near quarrelling about the treatment of Young.--In a few days after Dr Young died: I applied to Lord Melville for the superintendence of the Nautical Almanac: Mr Croker replied that it devolved legally upon the Astronomer Royal, and on May 30th Pond wrote to ask my a.s.sistance when I could give any. On June 6th I was invited to the Greenwich Visitation, to which I believe I went on the 10th.

"I had long desired to see Switzerland, and I wished now to see some of the Continental Observatories. I was therefore glad to arrange with Mr Lodge, of Magdalene College (perhaps 10 years senior to myself), to make a little tour. Capt. W.H. Smyth and others gave me introductions. I met Lodge in London, and we started for Calais on July 27th 1829. We visited a number of towns in Belgium (at Brussels I saw the beginning of the Observatory with Quetelet), and pa.s.sed by Cologne, Frankfort, Fribourg, and Basle to Zurich. Thus far we had travelled by diligence or posting: we now procured a guide, and travelled generally on foot. From the 13th to the 31st August we travelled diligently through the well-known mountainous parts of Switzerland and arrived at Geneva on the 31st August. Here I saw M. Gautier, M. Gambard, and the beginning of the Observatory. Mr Lodge was now compelled to return to Cambridge, and I proceeded alone by Chambery to Turin, where I made the acquaintance of M. Plana and saw the Observatory. I then made a tour through north Italy, looking over the Observatories at Milan, Padua, Bologna, and Florence. At Leghorn I took a pa.s.sage for Ma.r.s.eille in a xebeque, but after sailing for three days the weather proved very unfavourable, and I landed at Spezia and proceeded by Genoa and the Cornici Road to Ma.r.s.eille. At Ma.r.s.eille I saw M. Gambart and the Observatory, and pa.s.sed by Avignon, Lyons, and Nevers to Orleans, where I visited my old host M. Legarde. Thence by Paris, Beauvais, and Calais to London and Cambridge, where I arrived on the 30th October. I had started with more than _140_ and returned with _2s. 6d_. The expedition was in many ways invaluable to me.

"On my return I found various letters from scientific men: some approving of my method for the ma.s.s of the Moon: some approving highly of my printed observations, especially D. Gilbert, who informed me that they had produced good effect (I believe at Greenwich), and Herschel.--On Nov. 13th I gave the Royal Astronomical Society a Paper about deducing the ma.s.s of the Moon from observations of Venus: on Nov. 16th a Paper to the Cambridge Philosophical Society on a correction to the length of a ball-pendulum: and on Dec. 14th a Paper on certain conditions under which perpetual motion is possible.--The engravings for my Figure of the Earth in the Encyclopaedia Metropolitana were dispatched at the end of the year. Some of the Paper (perhaps much) was written after my return from the Continent.--I began, but never finished, a Paper on the form of the Earth supposed to be projecting at middle lat.i.tudes. In this I refer to the printed Paper which Nicollet gave me at Paris. I believe that the investigations for my Paper in the Encyclopaedia Metropolitana led me to think the supposition unnecessary.--On Nov. 6th I was elected member of the Geological Society.

"On Nov. 16th 1829 notice was given of a Grace to authorize payment to me of _157. 9s. 1d._, in conformity with the regulations adopted on Feb. 27th, and on Nov. 18th the Grace pa.s.sed the Senate. On Nov. 19th the Vice-Chancellor wrote me a note enclosing the cheque. On Nov. 23rd (practically the first day on which I could go) I went to London and travelled to Edensor, where I arrived on the 26th. Here I found Richarda Smith, proposed to her, and was accepted. I stayed there a few days, and returned to Cambridge."

1830

"On Jan. 25th 1830 the Smith's Prize Paper was prepared. I was (with my a.s.sistant, Mr Baldrey) vigorously working the Transit Instrument and its reductions, and gradually forming a course of proceeding which has had a good effect on European Astronomy. And I was preparing for my marriage.