In the meanwhile arose a controversy with Hooke, the universal claimant, who, when the first part of the manuscript was presented by Vincent, asserted that ho had diseoi-ered the law of the inverse squares, and had communicated that and other discoveries to Newton. The heads of the paper on which he founds his claim are given at length in HOOKE, ROBERT, in Bloc. Div., and they show that though he had (in common with several others) some very correct notions on the subject, he had not even arrived at the knowledge of the law of the inverse squares, though that had been propounded by BOUILLAIID [B100. Div.]. Mr. Rigaud enters at great length into this question ; if we were to do the same, we should take an advanced position, and before we attempted to show that Hooke did not write any part of the substance of the Principia, we should require reasonable proof that he would have been able to read and understand the mathematical part of it when Written : and not until this had been given, we are con vinced could not be given from Hooke's writings, should we consider it necessary to enter on the first point. Had it not been for Halley, this trumpery claim of Hooke's would have produced serious con sequences. Newton, easily disgusted by controversy, and having ob served that physical questions generally gave rise to it, proposed (in a letter to Halley, June 20, 1686) to omit the third book altogether, which contains the actual application of the first two books to the existing universe. He says, " The third I now design to suppress. Philosophy is such an impertinently litigious lady, that a man had as goad be engaged in lawsuits as have to do with her. I found it so formerly, and now I have no sooner come near her again, but she gives me warning. The two first books, without the third, will not so well bear the title of Philmeophim Naturalis Principia Mathematica,' and therefore I had altered it to this,—' De Motu Corporum Libri Duo,' but upon second thoughts, I retain the former title. 'Twill help the sale of the work, which I ought not to diminish now 'tis yours." Halley had to soothe this irritation, and prevent the consequences ; and as the letter in which he did this is very curious, and has never been printed altogether, except by Mr. Rigaud, the surpassing interest which everything connected with the Prineipia excites will justify our giving it entire, particularly as it is the original voucher for several of the most Important circumstances connected with the publication • " London, 29 June, 1686.
" Sir,—I am heartily sorry that in this matter, wherein all mankind ought to acknowledge their obligations to you, you should meet with anything that should give you disquiet ; or that any disgust should make you think of desisting in your pretensions to a lady whose favours you have so much reason to boast of. 'Tis not she, but your rivals, envying your happiness, that endeavour to disturb your quiet enjoyment; which, when you consider, I hope you will see cause to alter your resolution of suppressing your third book, there being nothing which you can have compiled therein, which the learned world will not be concerned to have concealed. Those gentlemen of the Society to whom I liave communicated it, are very much troubled at it, and that this unlucky business should have happened to give trouble, hating a just sentiment of the author thereof. According to your desire in your former, I waited upon Sir Christopher Wren, to inquire of him, if he had the first notion of the reciprocal duplicate proportion from Mr. Hooke. His answer was, that he himself very many years since had had his thoughts upon the making out the planets' motions by a composition of a descent towards the sun, and an impressed motion ; but that at length he gave it over, not finding the means of doing it.. Since which time Mr. Hooke haul frequently told him, that he had done it, and attempted to make it out to him ; but that he never was satisfied that his demonstrations were cogent. And this I know to be true, that in January, 1633-4, I, having, from the considerations of the sesquialter proportion of Kepler, concluded that the centripetal force decreased in the proportion of the squares of the distances reciprocally, came on Wednesday to town, where I met with Sir Christopher Wren and Mr. I fooke, and falling in discourse about it, Mr. Hooke affirmed, that upon that principle all the laws of the celestial motions were to be demonstrated, and that he himself had done it. I declared the ill-success of my own attempts ; and Sir Christopher, to encoui ase the inquiry, said that he would give Mr. Hooke, or me, two time to bring him a convincing demon stration thereof ; and, besides the honour, he of us, that did it, should have from him a present of a book of forty shillings. Mr. Hooke then said, that he had it, but he would conceal it for some time, that others trying and failing might know how to value it, when he should make it public. However, I remember that Sir Christopher was little
satisfied that he could do it; and though Mr. Hooke then promised to show it him, I do not find that in that [articular ho has been so good as his word. The August following, when I did myself the honour to visit you, I then learnt the good news that you had brought this demonstration to perfection : and you were pleased to promise me a copy thereof, which the November following I received with a great deal of satisfaction from Mr. Paget ; and thereupon took another journey to Cambridge, on purpose to confer with you about it., since which time it has been entered upon the Register books of the Society. As all this passed, Mr. Hooke was acquainted with it, and according to the philosophically ambitious temper he is of, ho would, had ho been master of a hie demonstration, no longer have concealed it, the reason ho told Sir Christopher and mo now ceasing. But now, be says, this is but one small part of an excellent system of nature, which he has conceived, but has not yet completely made out, so that he thinks not fit to publish one part without the other. But I have plainly told him, that unless he another differing demonstration, and let the world judge of it, neither I nor any one else can believe it. As to the manner of Mr. Hooke's claiming the discovery, i fear it has been represented in worse colours than it ought ; for ho neither made public application to the Society for justice, nor pretended you had all from him. The truth ie this : Sir John Heakyns, his particular friend, being in the chair when Dr. Vincent presented your book, the Doctor gave it its just encomium both as to the novelty and dignity of the subject. It was replied by another gentleman, that you had carried the thing so far, that there was no more to be added. To which the Vice-president replied, that it was so much the more to be prized, for that it was both invented and perfected at the same time. This gave Mr. Hooke offence, that Sir John did not, at that time, make meution of what he had, as he said, discovered to him; upon which they two, who till then were the most inseparable cronies, have since scarce seen one another, and are utterly fallen out. After the breaking up of that meeting, being adjourned to the coffee-house, Mr. Hooke did there endeavour to gain belief, that he had some such thing by him, and that ho gave you the first hint of this invention. But I found, that they were all of opinion, that, nothing thereof appearing in print, nor on the books of the Society, you ought to bo considered as the inventor. And if in truth he knew it before you, he ought not to blame any but himself, for having taken no more care to secure a discovery which he puts so much value on. What application he has made in private, I know not; but I am sure that the Society have a very great satisfaction, in the honour you do them, by the dedication of so worthy a treatise. Sir, I must now again beg you, not to let your resentments run so high, as to deprive us of your third book, wherein the application of your mathematical doctrine to the theory of comets and several curious experiments, which, as I guess by what you write, ought to compose it, will undoubtedly render it acceptable to those who will call themselves Philosophers without Mathematics, which are much the greater number. Now you approve of the character and 'paper, I will push on the edition vigorously. I have sometimes had thoughts'of having the cuts neatly done in wood, so as to stand in the page with the demonstrations. It will be more convenient, and not much more charge. If it please you to have it so, I will try how well it can be done; otherwise I will have them in somewhat a larger size than those you have sent up. I am, Sir, your most affectionate humble servant, " E. HALLEY." The authorities on this subject are-1, Rigaud, Historical Essay on the First Publication of the Principle,' Oxford, 1838, 8vo. ; 2, Ed leston, Correspondence of Sir 1. Newton and Prof. Cotes,' London, 1850, Svo.; 3, Brewster, Memoirs of Sir I. Newton, London, 1855, 2 vole. Svo. Rigatid'a research was of the most acute and accurate character. Mr. Edleston has added a biography in the form of annals with notes, the most convenient reference on Newton which exists and his researches, especially. those made in Trinity College, have been laborious and successful. Sir D. Brewster had the celebrated Ports mouth papers in his possession, and has produced the most detailed life of Newton which exists. An immense deal has been done for the biography of Newton in the last twenty-five years: but the subject will never be finally settled until the Portsmouth papers have been allowed to undergo the most searching and leisurely scrutiny from men of all opinions on disputed points.