Pursuant to this requeft, obfervations of equal altitudes were taken at Portfmouth by Mr. Robertfon, mafter of the Royal Academy, and the watch was fet to the true time of that place; and on the 18th of November 1761, Mr. Harrison failed from Portsmouth, for Jamaica, in the Deptford, commanded by captain Digges. On the 8th of December, by obfervation, the Deptford was, in the latitude 35°. 17′ N. and in the longitude by the watch 15°. 17 W. from Portsmouth; but by the ship's reckoning only 13. 50'. and most of the ship's company were fo confident of their reckoning being right, that they wanted to fteer more to the weftward in order to make the island of Porto Santo, as they were in want of beer, and afraid of lofing time. The captain, however, though he offered to lay five to one that the fhip was three days run too far to the caftward, refufed to alter his course, as Mr. Harrison affirmed, that if the above island was accurately Jaid down in the maps they muft fee it the next morning. His prediction proved true; for at feven in the morning the ifland appeared, upon which both the captain and crew were very thankful to Mr. Harrison for keeping the fhip's reckoning by the watch, as otherwife they should not have feen the island of Madeira at all. During the voyage from Madeira to Jamaica, the time-piece corrected the errors of the log, when they were full as great as in the voyage from Portfmouth. On their arrival at Jamaica, it appeared that the difference of longitude as found by the timepiece, and calculated by the obfervations of the tranfit of Mercury, was only five feconds of time, which, at Jamaica is little more than a geographical mile. After ftaying a few days on the ifland, Mr. Harrison failed for England in the Merlin floop, and the weather during great part of their paffage proved fo very tempeftuous that they were obliged to place the time-piece on the counter in order to avoid its being perpetually expofed to the fea-water. In this fituation it fuffered continual violent agitations, which could not fail of retarding its motion in fome degree, yet it was found that the time-piece during the whole voyage from Portsmouth till its return had loft only one minute fifty-four feconds and a half; which in the latitude of Portsmouth amounts to about eighteen geographical miles, or minutes of a great circle, whereas the act requires no more than that it should come within the distance of thirty geographical miles. But notwithstanding the accuracy with which the time was kept by the machine, fome difficulties arofe with regard to the longitude of Jamaica, which was faid to be not fufficiently known, notwithstanding it had been determined by accurate obfervations on a tranfit of Mercury over the fun on the 25th of October October 1743. Mr. Harrison, however, fubmitted to make a fecond experiment of the correctnefs of his time-keeper, by another voyage to the West-Indies; and the island of Barba does was fixed upon by the commiflioners of longitude for that purpose. Accordingly Mr. Harrison carried his machine on board the Tartar at Spithead, and on the 8th of March 1764, fail.d for Barbadoes. In their paffage to the Canaries they met with hard and contrary gales, especially in the Bay of Bifcay. On the 18th of April, Mr. Harrifon declared, that they were fortythree miles to the eastward of Porto Santo; on which the captain (Sir John Lindley) fteered directly for it, and at one the next morning they faw the island, which exactly agreed with the distance given by Mr. Harrifon. On the 13th of May they arrived at Barbadoes, Mr. Harrifon having during the whole voyage declared how far they were diftant from that ifland, according to the best accounts of its longitude. The day before they made the island he declared the distance, and the captain found his declaration to be true. Soon after their return, Mr. Harriton prefented a memorial to the commifiioners of longitude, in answer to which they declared, they were unanimoufly of opinion, that the memorialift's time-keeper had kept its time with fufficient exactnefs, and without lofing its longitude in a voyage from Portsmouth to Barbadoes, beyond the nearest limit required by the act of the twelfth of queen Anne; but even confiderably within the fame. They added, however, that as Mr. Harrison had not made a difcovery of the principles upon which his faid time-keeper is conftructed, nor of the method of carrying thofe principles into execution, by means whereof other time-keepers might be framed, of fufficient correctness to find the longitude at fea, within the limits required by the act, whereby the inven⚫tion might be adjudged practicable and ufeful in terms of the • faid act, and agreeable to the true intent and meaning thereof; they did not therefore think themselves authorised to grant any "certificate to Mr. Harrifon until he has made a full and clear difcovery of the faid principles and method, and the fame fhall have been found practicable and ufeful to their fatisfaction. They however declared they were of opinion, that application fhould be made to parliament for leave to pay to Mr. Harrison, on his producing his time-keeper to certain perfons to be named by the commiffioners, and difcovering to them the principles and manner of making the fame, so much money as will make up the fums already advanced to him 10,000 exclufive of what he has received on account of improving his time-keeper; and moreover to pay him the remainder of the reward of 20,cool. on proof being made to • their F 2 • their fatisfaction that his method will be of common and general utility in finding the longitude at fea, within the nearest • limits required by the act of the 12th of queen Anne.' Application was accordingly made to parliament and a bill in confequence of it was paffed during the last feffion, for granting Mr. Harrison 10,000l. for difcovering the longitude by his time-piece, and 10,000 l. more if it fhould equally answer in a voyage to be made by way of trial to Hudfon's Bay. But dif putes have hitherto prevented Mr. Harrison from receiving the above reward. It has indeed been faid, that the inftrument does not keep equal time, being confiderably affected by heat and cold, and that Mr. Harrifon, in order to determine the variations of his machine, has conftantly had recourfe to a thermometer. But we cannot help doubting the validity of this objection, because it appeared, that the inftrument had loft only one minute fiftyfour feconds and a half during the whole paffage to and from Jamaica, as we have already obferved. And it must therefore furely be very abfurd to fuppofe that the errors arifing from heat and cold could fo accurately correct each other, especially when it is remembered that the voyage to Jamaica was in December, and confequently the fhip muft pafs from extream cold to extream heat; whereas the voyage home was four months after, and therefore at a time when the weather was very different with regard to heat and cold. To which if we add the finding the Madeiras, and other iflands during the paffage to Jamaica, it feems hardly poffible to doubt that the machine kept equal time during the whole voyage. It muft after all be admitted, however, that even fuppofing' Mr. Harrison's machine fufficiently exact, it is poffible that it may not entitle him to the reward of 20,000 1. above-mentioned." For, ifits conftruction be of fo nice and complicated a nature, as not to admit of its being of common and general utility at fea, his method certainly does not come within the intent and meaning of the act by which that reward is granted. The inftrument can be of little ufe, if it requires the conftant attendance of an artift of equal experience and ingenuity with the inventor. On the other-hand, it is prefumed the Commiffioners of the Longitude do not expect that Mr. Harrifon's machine fhould come' as cheap, or be as little liable to accidents, as the common foreftaves, and compafs-boxes that are fold at the Ship-chandlers.' Hence we conceive that the difference between Mr. Harrison and the Commiffioners might be eafily adjusted, if they could agree about the conftruction of the words common and general utility. B Minutes of the Proceedings of the Commiffioners appointed by Act of Parliament for the Discovery of the Longitude at Sea, at their Meetings on the 25th, 28th, and 30th of May, and 13th of June, 1765, with respect to carrying into Execution fo much of an Alt paffed in the laft Seffions of Parliament, as relates to the giving Mr. John Harrifon a Reward, upon his making a Difcovery of the Principles of his Watch or Time-keeper. 4to. 6d. Billingsley. TH HESE minutes relate to the difference between the Commiffioners of Longitude, and Mr. Harrison; and the following are the principal circumftances. At a meeting at the Admiralty on Tuesday the 28th of May, 1765, the act paffed in the last feffion of parliament for explaining and amending thofe of the 12th of Queen Anne, and 26th of George II. was read: after which the board went into the confideration of proper means for carrying the faid act into execution; and having difcourfed fome time upon that part of it which relates to giving a reward to Mr. John Harrison, upon his difcovering the principles of his watch or time-keeper, his fon, who was attending, was defired to inform the board, in what manner his father proposes to difcover the faid principles. He answered, that he was commiffioned by him to deliver to the board the identical drawings from which his faid watch or timekeeper was made, with explanations thereof in writing; and that his father expects that the Commiffioners will, upon receipt of the faid drawings and explanations, give him a ce tificate to enable him to receive the first reward directed to be paid him by the above-mentioned act; and that he is not authorized by his father to offer any other mode of discovery. He then withdrew. The board then took into confideration the method of difcovery propofed by Mr. Harrison, and being unanimously of opinion, that drawings and written explanations alone, will not be a fufficient and fatisfactory difcovery of the principles of the faid watch or time-keeper, agreeable to the before-mentioned act; Refolved, That Mr. Harrifon be acquainted, that the Commiffioners do expect his compliance with what is undermentioned, before they can give him the certificate he requires, viz. 1. That he shall difcover fully, by drawings and a written explanation, the principles upon which his faid watch is conftructed, and deliver the fame to this board, upon oath. 2. That he fhall give a farther explanation by word of mouth, and experimental exhibitions where judged neceffary, of the faid principles, and of every thing relative to the conftruction of he laid watch; producing the fame; taking it to pieces; and anfwer F 3 answering, upon oath, to every question proposed by the board, and fuch perfons as may be appointed by them for the examina tion thereof. 3. That he is to make over the property of the three feveral timekeepers, and the watch, when he fhall receive his certificate. Mr. Harrifon's fon was then called in, and these refolutions having been read to him, and a copy given him to fhew to his father, he withdrew. At a meeting at the Admiralty on Thursday the 30th of May, 1755, Mr. John Harrifon was called in, (together with his fon) and difcourfed with concerning the method propofed for the discovery of the principles of his watch or time-keeper; and consented to do it agreeable to the refolutions of the last board. The board then took into confideration the nomination of proper perfons to be prefent when the difcovery fhall be made: And, after fome time spent therein, Mr. Harrifon and his fon were again called in; and fome perfons, who were named by the Commiffioners, having been objected to by them, the board came to the following refolutions, which were agreed to by Mr. Harrifon, viz. That, in addition to fuch of the Commiffioners who shall chufe to be prefent, three gentlemen skilled in mechanicks, and three watchmakers, be appointed to attend when the abovementioned discovery shall be made. Refolved, That it be an instruction to fuch of the above-mentioned gentlemen and watchmakers, as may be inclined to attend, to meet Mr. Harrison as foon as poffible, and to continue their meetings with him without interruption: And that they be enjoined not to make any discovery of the principles of the watch to any but the board, without leave of the Commiffioners. AT a meeting at the Admiralty on Thursday the 13th of June, 1765, Right Honourable Earl of Egmont, First Lord Commissioner of the Admiralty. Sir John Cuft, Speaker of the Houfe of Commons. Henry Ofborn, Efq; Admiral of the White. Honourable John Forbes,Admirals of the Blue, They are named in the minutes; but we have omitted them in this abstract, Right |