At the court martial held on the morning of 3 July 1699, we saw that Halley effectively lost his case against his lieutenant, Edward Harrison, and other officers, as the court declared them not guilty, issuing only a severe reprimand.
Halley was none too pleased with this outcome and the next day put his view of events in a letter to Josiah Burchett, Secretary to the Admiralty.
I like this letter as I think it gives a good demonstration of Halley’s personality in the way it passes through a range of emotions but ends with an unchurlish acceptance that it is now up to him to prove himself to “their Lopps”. But the most important thing about the letter is that it finally reveals the reason for Harrison’s hostility towards him.
(Halley to Burchett, dated 4 July 1699 from the “Paramore pink riding in the Downes”, National Archives ADM 1/1871)
Honoured Sr
Yesterday at the Court Martiall I fully proved all that I had complained of against my Lieutenent and Officers, but the Court insisting upon my proof of actuall disobedience to command, which I had not charged them with, but only with abusive language and disrespect, they were pleased only to reprimand them, and in their report have very tenderly styled the abuses I sufferd from them, to have been only some grumblings such as usually happen on board small shipps. My Lieutenent has now declared that I had signally disobliged him, in the character I gave their Lopps of his Book, about 4 years since, which therfore, I know to be the cause of all his spight and malice to me, and it was my very hard fortune to have him joyned with me, with this prejudice against me. Howsoever their Lopps may resent it, I am sure that never any man was so used by a Lieutenent as I have been, during the whole term of the Voiage, nor could I any wais help my self when abroad: It remains for me to show their Lopps that as to the Principall business I went upon, my Voiage has not been ineffectuall, and I humbly hope they will suspend their censure till I can prepare for them the Theory of the Variation of the Compass and of the changes therof, for which I have now obtained a competent Stock of Materialls. I have my sailing Orders, but it blows so fresh at North that the pilote thinks not fitt to weigh.
I am
Your Honours most obedt. Servt
Edm. Halley
So the reason for Harrison’s animosity was that Halley gave his book a bad review!
Harrison’s book, Idea Longitudinis, was published in 1696 and offers his thoughts on methods of finding longitude at sea. He sent copies to the Admiralty and to the Royal Society – and remarkably, that copy is still in the Royal Society’s archives today.

The Royal Society’s copy of Harrison’s book, Idea Longitudinis

The cover of Idea Longitudinis

The title page
The Royal Society’s copy has an inscription written by Harrison: “To The Royall Society of London this Small treatise entituled Idea Longitudinis is humbly presented by Edw: Harrison”.

Harrison’s inscription
In my next post, we’ll take a closer look at Harrison’s book and consider whether Halley’s dismissal of it was justified.
(Many thanks to the Royal Society for kindly allowing me to show the above photographs.)