This post is a transcription plus commentary of the Board of Longitude’s 1767 document “The Principles of Mr. Harrison’s Time-keeper,” sought by the author. From scans on the University of Cambridge Digital Library, a great article on “watchesbysjx” revealed the microscopic magic of H4, Harrison’s First Sea Watch. The text is updated for modern readability, with mentions of Harrison’s improvements to clock accuracy, eccentric adjustment methods, and the division of the watch’s components. Harrison’s unique approach to clock resistance, balance diameter, and meticulous material selection sheds light on his innovative timekeeping methods. Controversially, Harrison’s disdain for oil application in clock maintenance goes against common watchmaker practices.
https://incoherency.co.uk/blog/stories/principles-harrison-timekeeper.html