Footnotes:

[1] It may not perhaps be improper here to observe, that the Locks were such as might be picked with a crooked Nail, that the Lock of which the Officers had the Key was on the 10th of July out of Order, and that Mr. Maskelyne was sorry this should ever come to the Ear of the Publick.

[2] “We whose Names are hereunto subscribed do certify, that Mr. John Harrison has taken his Time-Keeper to Pieces in the Presence of us, and explained the Principles and Construction thereof, and every Thing relative thereto, to our entire Satisfaction; and that he also did to our Satisfaction answer to every Question proposed by us or any of us relative thereto; And that we have compared the Drawings of the same with the Parts, and do find that they perfectly correspond.”

[3] It may not be amiss to take Notice here of an Objection that was raised by two of the Commissioners, both famous for their Knowledge in Astronomy; viz. That the Observations of equal Altitudes made at Portsmouth, could not be depended on, because the equal Altitude Instrument had been removed from the Place of Observation in the Morning, to another Place to make the Afternoon Observations; from which it is plain that these great Astronomers did not understand either the Principles or Use of one of the most simple Instruments in Astronomy.

[4] If this Interpretation of the Act was true, and the Commissioners had a general discretionary Power, where was the Reason or Use of specifying any Trial at all in the original Act?

[5] The Board contracted with Mr. Kendall (one of the six Persons to whom the Discovery was made) to make a Watch after the Model of mine. He was to be paid for every Thing before-hand, and to begin in a Twelvemonth after making the Bargain; he is to make Parts like Parts, but is not to be answerable for his Watch’s going at all. My Timekeeper is now in his Possession, tho’ he is not yet ready to make Use of it; There are some Parts in the making of which the Model can be of little or no Use to him; I only desired it for six or eight Months, and am confident he can have no Occasion for it before that Time is expired: however I have offered to have it forth coming whenever Mr. Kendall declares that he wants it, therefore I apprehend their Engagements with Mr. Kendall afford no solid Reason for the Commissioners to refuse lending it to me.

[6] In the fifth Volume of M. De La Caille’s Ephemerides, Page 31, he says, “that any Person would be in the wrong to suppose that the Longitude at Sea can be determined by the Moon, to a less Error than two Degrees, let the Method which is employed be never so perfect, let the Instruments, of the Sort now in use, be never so excellent, and let the Observer be the most able and accomplished. For if we examine, without prejudice, all the Circumstances which enter into the Calculation and into the Observation of a Longitude at Sea, we shall be easily convinced, that it would be ridiculous to maintain, that the Sum of the inevitable Errors should not amount to five Minutes of a Degree, that is, to two Degrees and a half of Longitude.” N. B. M. de la Caille published this in the Year 1755, and is universally allowed to have been an excellent Observer, and made several Voyages by Sea, where he made Trials of this Method by the Moon.

Dr. Halley and Dr. Bevis (as appeared to the Honourable House of Commons upon an Examination of the latter) did, with an excellent Hadley’s Quadrant, rectified by Mr. Hadley himself, and in his presence, attempt to take the angular Distance of the Moon from Aldebaran, a Star of the first Magnitude; but with such bad Success (some of the Observations removing Greenwich from itself almost as far as Paris) that Dr. Halley seemed to be out of Hope of obtaining the Longitude by this Method.

Transcriber’s Notes: This ebook has been transcribed from the original print edition, published in 1767. Obvious printing errors have been corrected, while minor irregularities in the spelling have been retained. The table below lists all corrections applied to the original text.