Chapter XVIII

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CHAPTER XVIII.

NEWTON OCCUPIED WITH THE LUNAR THEORY — HIS CORRESPONDENCE WITH FLAMSTEED, THE ASTRONOMER-ROYAL — NEWTON'S LETTERS TO FLAMSTEED, PUBLISHED BY MR. BAILY — CONTROVERSY WHICH THEY OCCASIONED — FLAMSTEED'S LETTERS TO NEWTON DISCOVERED RECENTLY — CHARACTER OF FLAMSTEED, IN REFERENCE TO THIS CONTROVERSY — OF NEWTON, AND OF HALLEY — ALL OF THEM ENGAGED, WITH DIFFERENT OBJECTS, IN STUDYING THE LUNAR THEORY — NEWTON APPLIES TO FLAMSTEED FOR OBSERVATIONS ON THE MOON, AND ON THE REFRACTION OF THE ATMOSPHERE, WHICH FLAMSTEED TRANSMITS TO HIM — ANALYSIS OF THEIR CORRESPONDENCE — FLAMSTEED'S BITTERNESS AGAINST HALLEY — DIFFERENCES BETWEEN NEWTON AND FLAMSTEED — FLAMSTEED'S ILL HEALTH INTERFERES WITH HIS SUPPLYING NEWTON WITH OBSERVATIONS — NEWTON'S IMPATIENCE AND EXPOSTULATION WITH FLAMSTEED — JUSTIFICATION OF FLAMSTEED — BIOT ASCRIBES NEWTON'S LETTER TO MENTAL ILLNESS — REFUTATION OF THIS VIEW OF THE SUBJECT — NEWTON NEVER AFFLICTED WITH ANY MENTAL DISORDER.

WHILE Newton was supposed to be incapable of understanding his Principia, we find him occupied with the difficult and profound subject of the lunar irregularities. He had resumed this inquiry in 1692,^[1] and it was probably from the intense application of his mental powers which that subject demanded, that he was deprived of his appetite and sleep during that and the subsequent year. When Mr. Machin long afterwards was complimenting him upon his successful treatment of it, Sir Isaac told him that his head had never ached but when he was studying that subject; and Dr. Halley told Con <158> duitt that he often pressed him to complete his theory of the moon, and that he always replied that it made his head ache, and kept him awake so often, that he would think of it no more. On a future occasion, however, he stated to Conduitt, that if he lived till Halley made six years' observations, "he would have another stroke at the moon."^[2]

In order to verify the equations which he had deduced from the theory of gravity, accurate observations on the moon were required; and, for the purpose of obtaining them, Newton had arranged, in the month of July 1691, to pay a visit to Flamsteed at the Royal Observatory of Greenwich. Learning, however, that Flamsteed was at that time from home, he postponed his visit, and intimated what had been his intention, in a letter of introduction which David Gregory delivered to the Astronomer-Royal in August 1691.^[3] During this visit Gregory introduced the subject of the lunar irregularities, and, in a letter to Newton, gives him an account of the conversation which arose on this and other subjects. "Flamsteed," he says, "remembered you very kindly;" and, among other things, he said "that he did not believe the irregularity of the moon's motions in summer and winter is of that quantity your system would make it."^[4] In the letter delivered by Gregory, Newton had advised Flamsteed to publish a catalogue of the correct places of such fixed stars of the first six magnitudes, as had been observed by others, and afterwards, by way of an appendix, those observed by himself alone, — an advice which, from causes perhaps not then <159> known to Newton, struck a discordant key in the mind of Flamsteed. He believed that this advice was suggested by Halley, whom he considered as an enemy, who had misrepresented him to his friends as unwilling to print his observations. He enters, therefore, in a long letter,^[5] into an explanation of his reasons, for not printing his observations, and he concludes the letter with the severest animadversions upon Halley, which it is impossible to justify. "I have no esteem," he says, "of a man who has lost his reputation, both for skill, candour, and ingenuity, by silly tricks, ingratitude, and foolish prate; and that I value not all, or any of the shame of him and his infidel companions; being very well satisfied, that if Christ and his Apostles were to walk again upon the earth, they should not escape free from the calumnies of their venomous tongues. But I hate his ill manners, not the man. Were he either honest or but civil, there is none in whose company I could rather desire to be." Newton's reply to this letter, if he did reply, has not been found either among his own papers or those of Flamsteed.

Newton seems to have had no farther communication with Flamsteed till 1694,^[6] when a correspondence took place between them, which was continued with little intermission for nearly two years, and with the nature of which the public was not till lately acquainted. The late <160> Mr. Francis Baily having obtained access to the manuscripts of Flamsteed, in the possession of a private individual, and to other manuscripts and books of his which had been left in the Royal Observatory, found that they contained materials which he considered of inestimable value in the history of astronomy, and through the influence of the Duke of Sussex, the Lords Commissioners of the Admiralty were induced to print them at the public expense.^[7]

The general effect of this publication, and of the sentiments expressed by Mr. Baily, was injurious to the memory of Newton; and as the work excited a high degree of interest in every part of the globe where science was cultivated, the friends of the injured philosopher were roused in his defence, and the scientific world is still divided on the subject. In justifying himself for publishing certain parts of the correspondence, Mr. Baily remarks, "that the personal motives for withholding them have long passed away, and now ceased to exist; and however unpleasant and painful it must be to an enlightened mind to find such eminent characters as Newton and Halley mixed up with subjects of the kind to which I shall presently allude, and pursuing a line of conduct towards Flamsteed which tends to make them appear less amiable in our eyes, yet a proper regard for truth and justice prevents any suppressions at the present day of the many curious and important (though often at the same time lamentable) facts which these manuscripts <161> have, for the first time, brought to light. I have indeed," he continues, "in justice to the parties here alluded to, endeavoured to procure information of a contrary tendency from various sources, and sought for documents which might tend either to extenuate or explain the conduct of Newton and Halley in these proceedings, or to throw new light on the origin and nature of the quarrel that at a certain period of this history existed between Flamsteed and his two distingiushed contemporaries, but, notwithstanding all my researches, I regret that it has been hitherto without success."^[8]

In enumerating the repositories to which his researches extended in quest of information favourable to Newton and Halley, Mr. Baily mentions "the valuable collection of Newton's MSS. belonging to the Earl of Portsmouth," and states that he "found nothing in it to throw any light on the special object of his inquiries." From causes which I cannot explain, Mr. Baily had not lighted upon the letters of Flamsteed to Newton, which had been carefully preserved, and of which I have now before me nearly forty, which complete the correspondence^[9] between these two distinguished individuals, and enable us to form a more correct judgment on those delicate questions to which this controversy has given rise. Before proceeding, however, to give a general account of its history, the reader requires to have some knowledge of the position and character of the three distinguished men whose reputation is so deeply at stake.

Flamsteed, who was four years younger than Newton, held the high position of Astronomer-Royal, along with <162> the small living of Burstow, in Surrey. His salary was only £100 a year, and he was allowed nothing from Government, either to provide or repair instruments, or to pay the expenses of a computer for reducing his observations. He was, therefore, obliged to purchase, or to construct with his own hands, the instruments which he used, and to pay the expenses of a servant capable of making the calculations which he required. His observations, consequently, were his own property, and no private individual was entitled to demand them. Flamsteed was, from his infancy, a person with a feeble constitution, and, when Astronomer-Royal, was afflicted with severe headaches, and with the stone and other painful distempers; but he bore these with Christian resignation, and never failed to exhibit in his conduct, and to express in his writings, the humblest submission to the Divine will. But with all his piety and virtues, there was a defect of character which it is necessary to state. He was prone to take an unfavourable view of the motives, as well as the conduct of those with whom he differed; and when such impressions were once made upon his mind, it was almost impossible to dislodge them. The following anecdote from the autobiography of William Molyneux, Esq., the friend of Locke, gives a view of Flamsteed, which is in every respect consistent with that which he displayed in his controversy with Newton and Halley: — "Mr. John Flamsteed, the King's astronomer at Greenwich, was formerly my constant correspondent for many years,^[10] but upon publication of my Dioptrics, he took such offence at my placing a solution of his, of the 16, 17, and 18 proposi <163> tions thereof, after, and not before, the solution I myself gave of the said propositions,^[11] that he broke his friendship with me, and that, too, with so much inveteracy, that I could never bring him to a reconciliation, though I have often endeavoured it, so that at last I slighted the friendship of a man of so much ill nature and irreligion, how ingenious and learned soever."^[12]

Mr. Newton was at this time Fellow of Trinity College, and Lucasian Professor at Cambridge, and though his Principia had been for six or seven years before the public, its value was known but to a few, and his great talents not sufficiently appreciated. He had been long acquainted with Flamsteed, and, in a correspondence which he had with him about the comet of 1680, Flamsteed had considered him as "magisterially ridiculing an unanswerable opinion of his," which turned out to be true.^[13] In Newton's controversies with Hooke,^[14] too, we have noticed some traces of personal feeling which might have been spared; but it is in his relations with Locke that some of those little imperfections of character are seen which slightly reappear in his communications with Flamsteed. We do not refer to the opinions which he expressed when under a nervous irritation, but to those occurrences which induced Locke, in 1703, to state confidentially to his cousin. Lord Chancellor King, "that Newton was a nice man to deal with, and a little too apt to raise in himself suspicions where there is no ground."^[15]

Dr. Edmund Halley, who was twelve years younger <164> than Flamsteed, was resident in London, and clerk and assistant secretary to the Royal Society during the correspondence between Newton and Flamsteed. He was a man of the world, much esteemed in society, but was generally supposed to entertain infidel opinions. Under this impression, Bishop Stillingfleet refused to recommend him to the Savilian Chair of Geometry in Oxford, when he was a candidate along with David Gregory; and Bishop Berkeley, on very imperfect information, rashly ventured to dedicate the Analyst to him as an "infidel mathematician." "Mr. Addison," as has been stated,^[16] "had given Bishop Berkeley an account of their common friend Dr. Garth's behaviour in his last illness, which was equally unpleasing to both these advocates of revealed religion. For when Mr. Addison went to see the Doctor, and began to discourse with him seriously about preparing for his approaching dissolution, the other made answer, 'Surely, Addison, I have a good reason not to believe these trifles, since my friend Dr. Halley, who has dealt so much in demonstration, has assured me that the doctrines of Christianity are incomprehensible, and the religion itself an imposture.'" Flamsteed never scrupled to denounce Halley as a libertine and an infidel; and we regret to see that a modern writer has ventured to say that Halley was low and loose in his moral conduct, and an avowed and shameless infidel.^[17] Had such been his character, he never would have been the friend and companion of Newton. It is quite true that Halley was sometimes checked by Newton when he had said anything that appeared disrespectful to religion, by the mild reproof, "I have studied <165> these things — you have not;" and I have found a memorandum signed by Mrs. Conduitt, in which she says that Newton "could not bear to hear any one talk ludicrously of religion, and that he was often angry with Dr. Halley on that score, and lessened his affection for Bentley." Thus placed in the same category with Dr. Bentley, we have no doubt that Halley's speaking ludicrously of religion amounted to nothing more than his maintaining certain opinions about the existence of a pre- Adamite earth, and ridiculing vulgar errors which have been too frequently associated with religious truth.^[18]

These three eminent individuals were, in the years 1694 and 1695, engaged in nearly the same researches. They were all intently studying the irregularities of the moon's orbit,^[19] and had Halley not been a party, there is reason to believe that no difference would have arisen between Newton and Flamsteed. We have failed, like Mr. Baily, to discover the ground of Flamsteed's virulent antipathy to Halley, evincing a degree of hatred which no Christian could rightly cherish, and which no honourable man could avow, and still less record. The charge of infidelity and libertinism was, we fear, but the mask under which personal feelings were too readily expressed; and if David Gregory's memorandum of him be true, we have a satisfactory explanation of the origin of Flamsteed's enmity to Halley, in what Mr. Rigaud calls "his detected act of dishonesty." "Newton," says Gregory, "often told me, but especially in December 1698, that these tables (Flamsteed's lunar ones) were first made and computed <166> by Edmund Halley, and communicated to Flamsteed, and published by him without the knowledge of Halley, and that this theft was the origin of the eternal quarrels between Halley and Flamsteed. Newton said that he had seen the handwriting of Halley."^[20]

Under these circumstances, Newton and Halley were desirous of receiving from Flamsteed his observations on the moon, — observations of such value, that without them they could not proceed in their researches, and of such rarity that they could not obtain them from any other observatory in the world. In order to procure the observations which he required, Newton paid a visit to the Royal Observatory on the 1st of September 1694. Flamsteed shewed him 150 places of the moon calculated from his own observations, either by himself or "his hired servants," with the differences, in three synopses, between these places and those in the common tables of the moon, "in order to correct the theory of her motions." These observations were given to Newton on two conditions, which he accepted, 1st, that he would not, without Flamsteed's consent, communicate them to anybody; and 2dly, that he would not, in the first instance, impart the result of what he derived from them to anybody but himself.^[21]

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In a few days after this visit, Flamsteed addressed a letter^[22] to him, acknowledging the return of the two synopses of the moon's places, offering him more when he signifies his having occasion for them, and informing him that he "intends hereafter to cause his man to calculate them both from the observations and tables as soon as observed, whereby it will be soon evident whether the heavens will allow these new equations you introduce, <168> and if they will, how they are to be limited." During his visit to the observatory, Newton must have expressed a wish for observations to test his theory of atmospherical refractions, for Flamsteed mentions that he has set himself to inquire what refractions can be got from his observations, and promises that whatever he gathers from them shall be freely imparted to him. "I shall never," he says, "refuse to impart either the observations themselves, or my deductions from them, to any person that will receive them with the same candour as you do. If I desire to have them withheld from others who make it their business to pick faults in them, and censure them, and asperse me no less unjustly than ungratefully, you will not blame me for so doing. When H. (Halley) shews himself as candid as other men, I shall be as free to him as I was the first seven years of our acquaintance, when I refused him nothing that he desired. I am told by a friend of his that he is very busy calculating the moon's places on a sudden. Perhaps some hints he has got from you have set him to work anew, but except you have been as plain with him as you were with me, I am satisfied he will never be able to find out the parallactic equation,^[23] nor limit it without a bigger store of observations than he is possessed of, though he have many of mine made between 1675 and 1682.

"Since you went home, I examined the observations I employed for determining the greatest equations of the earth's orbit, and considering the moon's places at the times of . . . , I find that (if, as you intimate, the earth inclines on that side the moon then is) you may abate about 20″ from it, say that it may be only 1° 56′ 00″."

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Flamsteed concludes this curious letter, the first of the series, with a request that Newton would acquaint him how the observations agree with his conception, and with an offer of more observations upon due notice.

To this letter^[24] Newton returned an answer which must have been very agreeable to Flamsteed. After comparing the observations with his "conception," he was satisfied that by both together the moon's theory might be reduced to the exactness of 2 or 3 minutes, and that he believed he would be able to set it right this winter. For this purpose, however, he requested certain observations which he specified.

In a few days Flamsteed replied in a long letter of October 11, 1694, in which he mentions that Halley had applied for a sight of the lunar observations, and that he had come to Greenwich and taken notes from the synopses of the moon's places, which Newton had received, — an act of kindness which Flamsteed did not grant without "minding him of his disingenuous behaviour in several particulars."^[25]

For the table of refractions near the horizon, Newton was particularly thankful.^[26] He ascribed the differences of refraction at the same altitude to the different temperatures of the air, and suggested that Flamsteed should in all his observations note the state of the barometer and thermometer. He told him that he had dined with <170> Halley, and had much discourse with him about the moon; that Halley had asked for a sight of the observations which made the parallactic equation between 8′ and 10′, but that he had refused on account of the engagement to communicate them to nobody without his consent. "I am glad," he adds, "that there is like to be a new correspondence between you, and hope it will end in friendship."

Flamsteed, in his reply,^[27] is delighted to hear of the agreement between his observations and the theory. He offers to re-calculate any of the observations that may appear incorrect, and promises a new synopsis of the moon's places, along with one of all the observations from which he drew the small empirical table of the refractions. "Yesterday at London," he says, "I had a great deal of talk with Mr. Halley about the moon's motion. He affirmed the moon's motion to have been swifter in the time of Albategni than at present, and that the cause of it was by reason that the bulk of the planets continually increased. I gave him the hearing, and at last told him that his notion was yours, he answered 'in truth you helpt him with that.'^[28] He affirms farther, that the moon's apogee moves swifter in winter than in summer, and that the greatest equations of it are biggest when the sun is in perigee. That they are as big as Copernicus makes them, that is 13° 9′. This smells too, of your theories. I remember that you affirm all the equations biggest when the earth is nearest the sun. I should be glad to hear that you had found in what proportion the equations of the apogee and the eccentricity alter, and what are their greatest differences in the last, the quantity of the first, how the variations alter, and that you would please to impart it to me, that so hereafter I may calculate on sure grounds, <171> and compare not an apparently erroneous, but a true theory with my observations, whereby its faults may be corrected."

In Newton's reply of the 1st November, he answers Flamsteed's questions, and explains to him the menstrual parallax of the sun, which he estimates at 16″ or 20″, an equation depending on the ratio of the masses of the earth and moon, and which, as M. Biot remarks, is one of the most delicate corrections in our modern tables, amounting only to 8″.

"Perceiving^[29] that Newton was as yet only trying how his observations would consist with the emendations, and that he had not as yet limited them to his mind," Flamsteed would not urge him any farther for them, but trusts that when he has "determined what corrections or additions are to be made to that theory which it was his good fortune to meet with, and usher into the world, he doubts not but you will impart them as freely as he did the observations, where you limit or confirm them, to you."^[30]

On the 17 th November, Newton sends to Flamsteed his table of refractions, computed by applying a certain theorem to his observations; and he explains to him his plan of first obtaining a general notion of the lunar equations to be determined, and then by accurate observations to determine them, seeing "that there is a complication of small equations, which can never be determined till one sees the way of distinguishing them, and attributing to each their proper phenomena." He asks Flamsteed to have a little patience with him till he has brought the <172> theory he ushered into the world to competent perfection, fit to be communicated to him; and he promises "to gratify him to his satisfaction for the trouble he is at in this business."

In replying to this letter, Flamsteed^[31] says that "he <173> was displeased with him not a little for the offer, and ascribes it to the suggestion of some malicious friend, and assures Newton that he never did, and would scorn to receive money for any such service." Newton makes an apology^[32] for the mistake he committed, and requests that Flamsteed will let it pass, and concur with him in the promotion of astronomy; and, in order to appease his friend, he sends him the beautiful theorem by which he computed his table of refractions, — a theorem which M. Biot justly characterizes as giving the true analytical expression of the differential of refraction, such as it is now employed, and which cannot but be regarded as one of the highest efforts of Newton's genius.^[33]

In answering this letter on the 31st December, Flamsteed enlarges on the subject of refractions, and transmits a table of morning and evening refractions observed in June 1678, from 79° to 89° 50′ of zenith distance. He sends him two lunar observations, and explains why he has not sent him others that he had made. Newton informs him in return,^[34] that the theorem on refractions which he had sent him was defective in making the refractive power of the atmosphere as great at the top as at the bottom, and that he had found another theorem <174> which required consideration. "In the former theorem," he continues, "the areas are to be determined by the fifth lemma of the third book of the Principia." He then explains to him how the air being colder and more dense at sunrise, the refractions are then greater, and how from its being rarer in the evening, the refractive power is diminished. Flamsteed admits, in his reply,^[35] that the change of temperature is the principal, but not the sole cause of the alterations in the morning and evening refractions. Sir Jonas Moore told him often, that when he lived in the fens, he often saw "the beasts raised to his sight very much by the fogs that lay betwixt him and them; and he has heard the late King Charles and old sea-captains talking together about the sea-air, and relating how, standing upon Dover beach at high-water, they saw the streets of Calais very plain, but whilst they stood, as the water sunk, these objects sunk and at last disappeared."

Considering a table of refractions as the foundation of astronomy, and very necessary for Flamsteed's great work, Newton^[36] is anxious to present him with one in return for his observations, and, as he has found a new theorem which makes the calculation easy, he hopes, when he has recovered from a slight indisposition, to finish it. "Supposing," he says, "the atmosphere^[37] to be of such a constitution as is described in the 22d Prop. of my second Book, (which certainly is the truth,) I have found, that if the horizontal refraction be 34′, the refraction in the apparent altitude of 3° will be 13′ 3″; and if the refraction in this apparent altitude of 3° be 14′, the horizontal refraction will be little more than 37′." On the 15th March, Newton sends him his table of refractions, in which, at 3° <175> of altitude, the refraction is 13′ 20″, so that the table is the same as that published by Halley in the Phil. Trans., for 1721. "Newton," as M. Biot remarks, "is therefore the creator of the theory of astronomical refractions, as he is of that of the theory of gravity. But the first of these titles was hitherto unknown to us; and we can now see, that it is not one of his works which has given him the least trouble, on account of the number, the variety, and the dispersion of the physical elements which he required to discover, to collect, and to combine in its establishment."^[38]

In his letter of the 23d April 1695, Newton says, "when I set myself wholly to calculations, (as I did for a time last autumn, and again since Christmas, in making the table of refractions), I can endure them, and go through them well enough. But when I am about other things, (as at present,) I can neither fix to them with patience, nor do them without errors, which makes me let the moon's theory alone at present, with a design to set to it again, and go through it at once. When I have your materials, I reckon it will prove a work of about three or four months; and when I have done it once, I would have done with it for ever."

After writing other two letters, in one of which he expresses his desire to get the naked observations on the R. ascension and meridional altitude of the moon, and have them calculated by "his servant Sir Collins," he addresses Flamsteed in the following manner:^[39] — "After I had helped you where you had stuck in your three great works, that of the theory of Jupiter's satellites, that of your catalogue of the fixed stars, and that of calculating the moon's places from observations, and in all these things <176> freely communicated to you what was perfect in its kinds, (so far as I could make it,) and of more value than many observations, and what (in one of them) contains more than two months' hard labour, which I should never have undertaken but upon your account, and which I told you I undertook that I might have something to return you for the observations you then gave me hopes of, and yet when I had done, saw no prospect of obtaining them, or of getting your synopses rectified,^[40] I despaired of compassing the moon's theory, and had thought of giving it over as a thing impracticable, and occasionally told a friend so, who then made me a visit. But now you offer me these observations which you made before the year 1690, I thankfully accept of your offer, and will get as many of them computed as are sufficient for my purpose."

We cannot find in the seven unpublished letters which Flamsteed wrote to Newton from February 7th to July 2d 1695, inclusive, anything to justify this letter. Flamsteed begins his letter of February 7th with a long tirade against Halley, and promises that when they meet he will tell him his history, which is too foul and large for a letter: He mentions two different reports from London of Newton's death, which he was able to contradict: He tells him that his servant, his computer, has run away, and that he is teaching another: He sends him observations on refractions and on the eclipses of the moon in 1678 and 1682, and he complains of a report which, at his request, Newton succeeds in putting down, that Flamsteed refused to impart his observations to him. This request is preferred in the following manner:^[41] "You see how willing I am to accommodate you with what is necessary for clearing the motion of the moon, and how small a return I desire, — that <177> is only to know what equations you use at present in the moon, and what limitations you give them. Not that I have any desire or design to meddle with the restitution of her motions myself, but only to satisfy my own curiosity, and not to be ignorant of the use you have made of what you imparted to me, as I told you before. Only I must desire you to acquaint Mr. Bentley, (whom I know not,) but who, I am told, complains that the second edition of the Principia will come out without the moon, because I do not impart my observations to you, that I shall furnish you to your satisfaction in that particular.^[42] Had I heard of it from yourself, I had told you the contents of this letter some days since, and assured you the fault should not be laid to my charge." And he adds in a postscript, "what one friend may justly expect from another, you shall ever command from yours, J. F."

In his very short letter of July 13, 1695, Flamsteed takes no notice of the attack of Newton. He promises places of the fixed stars and the nonagesimal table, and adds, "a report is industriously spread in town that I have refused to impart any more observations to you. I heard that he who spreads it intends you a visit ere long. I hope you will take notice of his disingenuity in this particular, since 'tis only my violent distemper and your own silence that were the cause of mine. I shall answer yours more fully next week."

On the 18th Flamsteed replies, as might have been expected, to the charge which had been made against him. "I have just cause," says he, "to complain of the style and expression of your last letter. They are not friendly, but that you may know me not to be of that quarrelsome humour I am represented by the <178> Clerk of the Society, (Halley,) I shall wave all save this expression, that what you communicated to me was of more value than many observations. I grant it — as the wire is of more worth than the gold from which it was drawn.^[43] I gathered the gold matter, and fined and presented it to you sometimes washed. I hope you value not my pains the less because they became yours so easily. I allow you to value your own as high as you please, and require no other reward for what assistance I sometimes afford you, but that I may now and then see some of the workmanship; and if that be not ready when I desire it, or if you think it not fit to favour me with it, I can easily be contented. Nor do I take it amiss that you often take no notice of some small particulars whereon I have desired to know what you have determined. Since I know very well that in things of their nature it is difficult to determine, and we often change what at first we thought would need no alteration or towards none. I have altered my solar numbers five times, and would not be ashamed to change again if I saw reason for it. If you answer me that you have not determined whether any other than the usual equations are to be used in the Syzigies, if you are not resolved how the moon's mean motion is to be corrected, you may say it. I shall urge you no farther, and nevertheless whenever you let me know that it lies in my power to serve you, I shall do it freely. But you will not complain of me to others without cause, and thereby add to the affliction I suffer from my obstinate distempers, and the calumnies of disingenuous and impudent people, if you have any value for your friend and humble servant."

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This earnest remonstrance is acknowledged by Newton on the 20th of July, the day that he received it. "The report," he says, "was against his mind, and he has written to put a stop to it. . . . Such expostulations or expressions in your last and some other letters, as tend to a difference, I pass by. Pray take care of your health. Dr. Battely (chaplain to Archbishop Sancroft) was much troubled with violent headaches, and found it a certain cure to bind his head straight with a garter till the crown of his head was numbed; for thereby his head was cooled by retarding the circulation of the blood. 'Tis an easy remedy, if your pain be of the same kind."

Flamsteed was gratified with this letter. He thanked Newton^[44] for Dr. Battely's remedy, as it "shews your friendly concern for my welfare." "Your letter," he says, "sets all right betwixt us. I have as great a stock of patience, and as good an one as I have of observations, and 'tis all ways drawn out on every occasion to serve my friends. My indisposition hindered me from serving you as I desired. You mistook the reason of my silence. I hope you will have the patience on my account that you demand of me on yours. . . . . The next week I am going to my parsonage, but I shall take care to have you furnished with another sheet of observations before. If you would rather have any other than the remains of 1677, let me know it. I shall fit you according to your desires."^[45] In replying to this letter in the following <180> week,^[46] Newton tells Flamsteed "that he had an excuse sent him (from Bentley or Halley) for what was said at London about your not communicating, and that the report should proceed no farther." He is glad all misunderstandings are composed. He thanks him for the nonagesimal table, "which he designed to make himself, as it saves him labour." And he adds, "that as the transcribing of these things gives your servant trouble, and, for encouraging him, I shall order Will. Martin, the Cambridge carrier, to pay him two guineas if you please to let him call for it, or to pay it to his or your order in London, if you please to let me know where."^[47]

Flamsteed was annoyed by this proposal to pay his servant. "I take it very kindly," he says,^[48] "that you acquainted me with your intent to gratify him for his pains before you did it, but I must entreat you to forbear. He is paid all ready. A superfluity of moneys, I find, is all ways injurious to my servants. It makes them run into company, and waste their time idly, or worse. I take care he wants nothing. If you send him verbal acknowledgments of his pains, and commendations for his <181> care and fidelity in copying, it will be a reward for him, and encouragement the best you can give him, and further I cannot allow. . . . . Pray say nothing to anybody of your proposal."

In another letter on the 6th of August, he says, that during the last six years "he has done more towards the restitution of astronomy than has been done in some ages before;" and, after mentioning what he has accomplished in the nineteen years that he has been at Greenwich, he adds, — "I write this purposely to you, because I know a sparke (Halley) is with you, that complains much I have lived here twenty years and printed nothing. I do not intend to print a St. Helena catalogue, and for that reason I defer the printing of anything thus long, that when I do print it may be perfect, as by the grace of God it shall."

Newton closes this correspondence with a short letter, dated September 14, in which he intimates that Halley's determination of the orbit of the comet of 1683, by his theory, "answers all your observations and his own to a minute;" that he has just returned from a journey into Lincolnshire, and is going on another; and that "he has not got any time to think of the theory of the moon, or have leisure for it, for a month or above."

Flamsteed answered this letter on the 19th September,^[49] complains of his ill health, considers the theory of gravity confirmed by its giving the orbit of the comet conformable to observation, and hopes, by travelling, to have some small share of health left wherewith to serve his friends, "and to supply you with what is wanting to finish the theory of the lunar motions, which I hear you doubt not now but to render very nearly agreeable the heavens." <182> Having heard nothing from Newton for four months, Flamsteed writes him on the llth January 1696, and, after offering him "further observations of the moon," which may be of use to him, he says, — "But if what I hear be true, you will have little need of them, for I have been told, ever since I came out of Surrey, that you have finished the theory of the moon on incontestable principles; that you have determined six general inequalities not formerly known; and that nevertheless the calculations will not be much more troublesome or difficult than formerly. I am heartily glad to hear this, and should be more so to have it from yourself, for in truth I suspect you are scarce so forward; and I flatter myself with the opinion, that if you were, you would have acquainted me with it, as you promised both when I imparted the three synopses of lunar calculations, and observed places to you, and in your letters since. Pray let me know how far you are proceeded, you will oblige me, and, if you please, the true reason why I have had no letters from you this four months."^[50] Newton does not seem to have answered this letter. His appointment to the Mint, though not officially communicated to him, was well known; and all his time must have been occupied in preparing for the discharge of its duties.

In reviewing the remarkable correspondence which terminates with the preceding letter, and which has been regarded in such different lights, we have no hesitation <183> in saying, that the two charges against Flamsteed of ignorance of the importance of the theory of gravity, and of unwillingness to supply Newton with the observations he required for his lunar theory, have no sufficient foundation. With the exception of those occasional bursts of spleen against Halley, which must have been annoying to his friend, his letters to Newton — though sometimes of an irritating tendency — are yet respectful, and even affectionate, and exhibit not only a willingness, but an anxious desire to supply him with every observation he possessed, and even to make and to reduce new observations expressly for his use. His ill health, which often required him to travel for its recovery — his severe headaches, a pulmonary affection, and sharp attacks of the stone and gravel, frequently unfitted him for observing and reducing his observations, while the want of computers, for whose labours he was obliged to pay, and the necessity of visiting his living at Burstow, often prevented him from communicating his observations as quickly as Newton wished, and as he himself desired. When his letters are published, and read along with those of his correspondent, his good name will not, from this cause, greatly suffer in the estimation of posterity. Flamsteed was not the less a great man that he has been confronted with the greatest.

But while we thus justify the Astronomer-Royal, we must make some apology for the philosopher. Newton was not in good health during the correspondence which we have been examining. The depths of his mind were stirred with the difficulties of the lunar problem. The new views which burst upon him in its solution could be tested only by observation; and they who have felt the impatience of spirit when a speculation waits for the <184> verdict of an experiment or a fact, or who have started from their midnight couch to submit a happy idea to the ordeal of observation, will understand the sensitiveness of Newton when he waited whole weeks for the precious numbers which the Observatory of Greenwich only could supply. Newton certainly thought, as his letter of the 9th July shows, that the Astronomer-Royal had not been sufficiently active in his cause; and though he knew that he had no other right but that of courtesy to the observations he required, yet he had established another ground of right which he was entitled to urge, — the social right of reciprocal obligation. He had given Flamsteed for his use his valuable tables of refraction, and had computed for him, by months of labour, the equations for the apogee and eccentricity, and important tables of horizontal parallaxes, for the express purpose of making some return for the observations which he required. He was, therefore, entitled to press these grounds of claim upon Flamsteed when he thought "he saw so little prospect of obtaining what he wanted," as to make him "despair of compassing the lunar theory," and "giving it over as a thing impracticable."

Regarding the letter of Newton in this light, we have been greatly surprised at the view taken of it, and indeed of all his letters, by M. Biot. No philosopher, either of our own or of Newton's day, has done more justice to his labours, or shown a deeper affection for his memory, than that distinguished philosopher; and there is no living writer, whose appreciation of the feats of science is more valuable than his; but the view which he has taken of the idle story of M. Colin and the dog Diamond, charged with fire-raising among Newton's manuscripts, and of the influence of this accident upon the mind of <185> their author, is to us, and, we believe, to every Englishman, utterly incomprehensible. The story of the burning of the papers about 1691 or 1692, is entirely fabulous;^[51] but even if it were true, it produced no effect upon Newton's mind. His illness at that time, the want of his usual consistency of mind, a condition which every deep-thinker must have experienced, arose, as he himself distinctly declares, from want of sleep and appetite during the preceding year.

"Is it then," says M. Biot, "going too far to see in the incoherence of these letters (the letters to Flamsteed) a fatal resemblance to those which Newton wrote to Pepys and Locke two years before, and almost in the same months? Do we not equally discover in them the morbid irritability of a mind fatigued by the continuity of its meditations, and which, according to the avowal of Newton himself, could no longer sustain such great efforts?^[52] And if it be true that, at the end of 1692, the fire which destroyed a part of his works had already produced in him moral symptoms of the same kind, still more distressing, why should we be surprised to see him brought back to it by the renewal of researches as profound and as fatiguing on account of the vagueness of the data at his command, as were those which he executed and attempted on refractions and the lunar theory, from the months of October 1694 to September 1695, as we have already related. This wets his last spark."^[53]

M. Biot has expressed his surprise at the sensitiveness of Englishmen, on the allegation that Newton "had <186> fallen into phrenitis" — that is, was insane in 1692; but, however great that surprise may be, it cannot be equal to that which they feel at his persisting in the statement, and at the offensive aggravation of it, which is contained in the preceding extract. Before M. Biot had read the letters to Flamsteed, he had declared that Newton's intellect was permanently weakened by his illness of 1692, and yet he now finds, by the perusal of these letters, that Newton had put forth his highest powers two years after that event! But what surprises and offends us, and what must offend every friend of truth and of genius, at his new allegation, that Newton's great intellectual efforts in 1694 and 1695 brought him back into his phrenitis of 1692, from which he never recovered his usual powers of invention and discovery. His letters to Flamsteed exhibit no such symptoms, no incoherence of mind, and no failure of a mental or moral nature. In 1696, when he exchanged the daily pursuit of science for the active and engrossing duties of official life, he was capable of developing the highest powers of his genius. He displayed them in the preparation of the second edition of the Principia, and in his Optics. They appeared fresh and vigorous during the fluxionary controversy. They shone with a more subdued light in the discharge of his duties at the Mint; and no period of his life can be named when his intellectual arm was shortened, or his mental eye was dim. Even in extreme old age, his robust frame protected from decay the bright spirit which it enclosed, and, ripe for the spiritual world which he had ever contemplated as his home, he adorned the last years of his long and honoured life with the humility of the sage and the graces of the Christian.