And 3dly, That during the remaining 11 Days in each Month, when the Sun and Moon may, if the Weather is clear be observed at the same Time, no Reliance can safely be placed upon the best Instruments in the Hand of the best Observer for ascertaining the Longitude within the Limits of the Act of Queen Anne; and consequently, that how valuable soever the Lunar Tables may be for correcting a long dead Reckoning, and thereby telling us whereabouts we are, when we are not afraid of falling in with the Land, yet even during these 11 Days, they do not extend to the Security of Ships near the Shore.

This Method of ascertaining the Longitude by the Moon has already cost the Publick the Sum of 6,600l. at least, and yet no proper Experiment has been made of it.

I shall not presume to make any Reflections on the different Treatment the two Inventions have met with, nor will I take up more of the Reader’s Time by a Detail of the very earnest Attention paid by the French Government to this Object. If our Rivals in Commerce and Arts should rob us of the Honour as well as the first Advantages of the Discovery, I hope it will be admitted that the Fault is not mine: And I likewise flatter myself that I have now furnished sufficient Materials for the Justification of my Friends, and for shewing that the Cause which they from publick spirited Motives had the Goodness to espouse, was not unworthy of their Patronage.

Red-Lion-Square,
June 23, 1767 JOHN HARRISON.

FINIS.

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.