John Harrison The Man Who Found Longitude 1966 First Edition. book by Humphrey Quill ISBN:
Original price was: £149.95.£119.96Current price is: £119.96.
Used – Very Good
1 in stock
Description
Immediate dispatch from Somerset. Nice older book in good condition. 1966 First edition. Pages in excellent condition for age. No notes or highlighting. Gift message in front. Best copy I have seen. See images. Fantastic book.
About the book >.>.> Although John and James Harrison had succeeded in com pleting two wooden regulators by 1726 they were now face with the task of adjusting them so as to produce accurate time keeping over long periods. This must have been a most formid able task. Even to-day when the principles of clocks and watche are well known and their mechanism is more or less standard- ized adjusting a timekeeper to give an accurate performance can be a most vexatious and uncertain task. In Harrison’s case he was dealing with the unique and completely untried devices of his own invention and the inexplicable and recurring vagar- ies in timekeeping that inevitably occurred must have tried to the utmost his courage and perseverance. The task was made doubly difficult owing to the lack of any readily available time- standard against which the Harrisons could compare the per- formance of their new timekeepers. These clocks had been designed to be more accurate than any others in the world and for this reason any other fine timekeepers in the neighbourhood of Barrow even if they existed would have been useless except for very rough checks. A sundial too was of no practical value for quite apart from the fact that time as shewn by this device varies in accuracy from day to day throughout the year the graduations engraved on the plate are of necessity far too coarse to denote the time any closer than to within a minute or two. (SP)
Additional information
ISBN | |
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Format | Hardcover |
Publisher | John Baker |
Book author | Humphrey Quill |
Condition | Used – Very Good |
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