Mr. Maskelyne then comes to the Rate of its going in different Positions; and says, “It is obvious, these last-mentioned Trials of the Watch in a vertical Position could not be designed to shew how near it would go at Sea, where it can never obtain these Positions: the Intent of them is to prove how near Mr. Harrison’s Execution of his Watch comes up to his Principles, with respect to the making all the Arcs described by the balance, whether large or small, to be performed in the same Time, as Mr. Harrison asserts them to be.” Mr. Maskelyne here also might have had Candour enough to inform the Public, as I did him, that although the Watch was quite sufficient to answer the Purposes required of it in Navigation, and to fulfil what was prescribed by the Act of Queen Anne, yet it was far from being in a state of Perfection, as an universal exact Time-Keeper for every Purpose: I shew’d him and the rest of the Gentlemen the Reasons why the Machine then before them, would not go at the same Rate in such different Positions into which the Motion of a Ship could never put it; and whilst I explained to them those Imperfections in the particular Machine we were examining, I also in the clearest Manner I was able, pointed out the means of remedying them with certainty in others, which the Gentlemen skill’d in Mechanics seem’d perfectly to comprehend, and to be satisfied of the Truth which I again assert, that Watches made on my Principles will endure a much greater Motion and change of Position than they can ever be subject to in a Ship; and that they will not be affected by any Degree of Heat or Cold, in which a Man can live.
If any Thing was meant to be concluded with respect to me by this Experiment, either in Point of Property or of Reputation, common Justice would have required that I should have had an Opportunity of seeing the Facts ascertained; and when such a Trial was directed as put the Result in the absolute Power of a single Person, that I should have been satisfied of his Integrity, Disinterestedness and Ability for the purpose. I would not be understood to attack Mr. Maskelyne’s Knowledge of the Theory of Astronomy; as for any Thing I know to the contrary, it may be of the very first Rate, especially as the Commissioners have thought proper to entrust him with the Execution of their commands; and which he has ever been as ready to undertake: But alas! as to his skill in Mechanics, he knows little or nothing of the matter he has ventur’d to take in Hand.
I think it more consistent with the respect I owe to the Public, and myself, to speak out plainly, than to have recourse to Insinuations, on a Subject of this nature: I therefore declare, that I am not satisfied with the Truth of his reporting other Observations relative to the Longitude, as I do maintain that in both his Voyages the Observations which he said he made the Land by, were not calculated till after he had seen the Land; and I am certain those he has given, in the Publication now before us, are not genuine, for he pretends to find each Observation of the Transit of the Sun to the hundredth part of a Second of Time,—a Degree of exactness about twenty Times beyond what any other Observer has hitherto found practicable: Moreover I know him to be deeply interested in the Lunar Tables, a Scheme set up some Years ago for the Reward in Competition with my Invention, and for which large Sums of Money have already been paid by the Public.
Although I flatter myself the Reader is already in Possession of very sufficient Reasons for rejecting the whole Pamphlet as partial and inconclusive, yet I entreat his patient Attention whilst I advance one step farther, and shew, that although Mr. Maskelyne has presented us with a set of Observations which according to his mode of Calculation, prove what he advances, yet those very Observations when rightly reasoned upon prove the contrary; and that in each of the Periods he refers to, except those of the severe Frost and improper Positions (against which Mr. Maskelyne ought to have informed the World I never warranted this particular Watch) it kept Time with sufficient correctness to determine the Longitude within the limits of the Act of Queen Anne.
The Reader by this Time knows enough of the Subject to see, that in order to try whether the Watch would or would not keep Time with sufficient Exactness to determine the Longitude, Mr. Maskelyne’s first Operation, after receiving it, should have been to ascertain the Rate of its going. But no such Thing happened: he knew it had not gone exactly correspondent to mean Time, during the Voyage to Barbadoes; it had been publickly enough declared that its Rate of going had been since altered; and, if he had not received that Information, he might nay must have discovered it in the first 24 Hours Tryal; however, without once attending to this essential Circumstance, he goes to work, comparing the first Period of six Weeks (which he observes is generally reckoned the Term of a West-India Voyage) when it was in an horizontal Position, with mean Time, instead of the corrected Time, and each succeeding Period with that immediately preceeding it! Who can hesitate in pronouncing that his Conclusions must be all erroneous? He should first have ascertained the Rate of its going by a Length of Observations of the Sun or Stars, or by a perfect Pendulum Clock if he had such a one, and then have corrected the Time shewn by the Watch accordingly. However, supposing for a Moment his Facts to be genuine, I will deduce the real Result in the best Manner the Observations will admit, rejecting those made while the Watch was in improper Positions, and those during the Frost, for the same Reasons that Mr. Maskelyne lays no Stress upon them, and for those I have already stated. I shall therefore (pursuing his Idea of six Weeks) take it during the first tranquil six Weeks that it had, viz. from July the 6th, to August the 17th, in which Time it gained in all 11 Minutes, 50 Seconds, or 16 9⁄10 Seconds per Day which I will assume as the Rate of its going, or if Mr. Maskelyne pleases I will take the Average of his whole Time of Examination, from the 6th of July to the 3d of January and from the 9th of January to the 4th of March, which will come out at the Rate of 16 8⁄10 Seconds per Day fast, and I say that according to either of those Rates of going, the Watch kept the Longitude within the Limits of the Act of Queen Anne, during any Period of six Weeks that can be pointed out, excepting those of extreme Cold, and improper Position which have already been explained. I do not trouble the Reader with the Calculations: If I assert an Untruth, I shall hardly escape Contradiction.
There is another Inaccuracy, which tho’ of less Consequence, ought not to escape notice. One would naturally suppose when Mr. Maskelyne found the Watch went at this Rate of gaining on Mean Time, he would have been very exact in his Time of comparing it with his Clock; but on the contrary we find he was so irregular as to vary his Comparisons on succeeding Days from half an Hour to four Hours and 48 Minutes, and this not for a Time or two, but for one third of the whole Time he had it.
Mr. Maskelyne having shewn from the Result of his Calculation (which I have here proved to be false) that the Watch is not to be depended upon to determine the Longitude in a Voyage of six Weeks, then says, “these Considerations are sufficient to explain the Motives which might have actuated Mr. Harrison, as a Man of Prudence, in desiring to send his Watch two Voyages to the West Indies, upon his Idea that he should be intitled to the large Rewards prescribed in the Act of the 12th of Queen Anne, in Case his Watch kept Time within the Limits there mentioned, whether the Method itself was or could be rendered generally useful and practicable, or not;” this Insinuation (published under the Authority of the Commissioners of Longitude) that I had contrived a Trial which I knew the Watch would fulfil, whilst I was conscious that it would not answer the general Purposes of the Act of Queen Anne, and consequently that I had formed a villainous Scheme to rob the Publick of the Reward without really and effectually performing the Conditions, strikes me as a Charge of so atrocious a Nature, that I think myself not only justified in publishing to the World what has been done with respect to Trials of the Merit of my Invention, but even indispensably obliged so to do. I well know what I hazard thereby, and if the rest of my Reward cannot be obtained on Principles of National Faith and Publick Spirit, I am contented to forego it, but I will not descend into the Grave loaded with that Dishonour which my Enemies, availing themselves of their Rank or Offices, have, in various Ways, attempted to throw upon me.
In the first Place I must remark, that the Trial referred to was not fixed by me, but by an Act of Parliament passed so long ago as the Year 1714, which (after vesting certain discretionary Powers in Commissioners to judge what Methods are likely to prove practicable, and authorizing them to issue smaller Sums of Money) goes on to fix the last grand Test of the Merit of any such Invention, and enacts “that when a Ship, under the Appointment of the said Commissioners, shall thereby actually sail from Great Britain to the West Indies without losing her Longitude beyond certain Limits, the Inventor shall be intitled to certain Rewards.” Having from the Year 1726, employed myself in adapting those Principles which I had at that Time executed in a Pendulum Clock, to an Instrument or Time-Keeper so constructed as to endure the Motion of a Ship at Sea, and having made a Voyage to Lisbon and done sundry other Things during a Course of Years, mostly under the Direction of the Commissioners of Longitude, by way of preparatory Experiments, I thought the Invention sufficiently perfect about the latter End of the Year 1760, to go upon the ultimate Trial, which I accordingly applied for. My Son, after being sent to Portsmouth with the third Time-keeper (the fourth or Watch being to be sent to him) was kept there five Months, waiting for Orders; which having by returning to London at Length obtained, he went to Jamaica in the Deptford Man of War, and returned in the Merlin Sloop of War, having fulfilled every Instruction of the Commissioners. It remained to compute from the Astronomical Observations made at Portsmouth and Jamaica, whether the Watch had or had not kept the Longitude within the prescribed Limits; and as my Title to 20,000l. was to be determined thereby, I thought it but reasonable that I should name some Person to check the Computations, which was refused. The Commissioners appointed three Gentlemen for that Purpose, and on receiving their Report were pleased to declare that the Watch had not kept its Longitude within the above mentioned Limits.[3] Thoroughly convinced of the contrary (for I had the same Materials they had to calculate from) I required a Copy of the Computations which was also refused me; nor could I ever obtain a Sight of them either officially or through private Favour, ’till three Years afterwards, when they were ordered to be laid before the House of Commons; and it then appeared that two of the three Computations were absolutely inconclusive, proving nothing, and the third decided in my Favour. Further Proof of the Watch having succeeded in this Voyage may be found in the Journals of the House of Commons, Vol. XXIX. P. 546, in the Evidence of George Lewis Scott Esq; and Mr. James Short.
The Reader will easily believe I did not feel perfectly easy under this Treatment of an Invention to the perfecting of which (encouraged by the long continued Patronage of a Graham, a Halley, a Folkes, &c. &c.——learned Friends to Society, and Publick Good, whose Minds were too enlarged, and Spirits too liberal to admit that little Jealousy of inferior Artists, which since their Death I have been exposed to) I gloried in sacrificing every Prospect of Advantage from other Pursuits, and had willingly submitted to lead a Life of Labour and Dependence. However ’twas too late to retreat; and I had only one Means of Success left which was to follow the Commissioners in their own Way. Accordingly after many Difficulties (with a Relation of which I will not tire the Reader, as it is by no Means my Intention to meddle with any Subjects of Complaint, except such as are material to the forming a right Judgment of the Trials made and proposed) a second Voyage to the West Indies was agreed to in the latter End of the Year 1762, which Agreement was afterwards well nigh overset by the Commissioners insisting on such Astronomical Observations being previously made, as were next to impracticable in this Climate, and could be put into the Instructions for no other Reason that I could conceive, but to throw insuperable Difficulties in my Way, as they were not at all material to the Determination of the Matter in Question. However the Commissioners at Length gave up this Point on my Opinion of the Impracticability being confirmed by that of an Officer of the Navy distinguished for his Abilities and Skill in Matters of Astronomy. To take away all Possibility (as I thought) of this Voyage being rendered fruitless like the last, I then desired to have inserted at the End of the Instructions some few Words to this Purpose, “that provided the Experiment answered, the Commissioners present were of Opinion I should without further Trouble receive my Reward;” but my Son attending the Board with this Proposition was told by Lord Sandwich at that Time President, that it would be mere Tautology, for that their giving Instructions implyed the same Thing, and that if the Watch kept its Time within the Limits of the Act there could be no Doubt of my being entitled to and receiving the Reward, and nobody could take if from me. Upon the Faith of this, my Son went the Voyage to Barbadoes, in which the Watch kept its Time “considerably within the nearest Limits of the Act of Queen Anne,” as certified, even by the Commissioners themselves.
On the Success of this Trial being known, and after having employed near forty Years of my Life on the Faith of an Act of Parliament, was a Doctrine broached to me (as I solemnly declare for the first Time) that the Commissioners were invested with a discretionary Power of ordering other Trials and the fulfilling of other Conditions than those specially annexed by Act of Parliament to the Reward;[4] An Exposition of the Law, which I ever did and ever shall (until it is supported by legal Authority) totally reject and refuse Obedience to; for I do maintain, that before passing the last Act of Parliament I had as full and perfect a Right to the Reward of 20,000l. as any Free-holder in Britain has to his Estate; and I never would have desired nor ever will desire any better Satisfaction than a judicial Determination of that Point; which however it was very soon thought proper to preclude me from, by a new Law, passed at the Instance of the Commissioners of Longitude, placing me too certainly under the Discretion of the Commissioners and totally changing the Terms on which the Reward was to be given me, enacting that I should have half of it when I had disclosed the Principles and Construction of the Machine, and assigned over for the Use of the Publick the last made Timekeeper, together with the three others which were not so perfect as the last; and the other half when I should have made more Watches, without determining how many, and proved them to the Satisfaction of the Commissioners, without defining the Mode of Trial.