An Act for explaining and rendering more effectual Two Acts … with regard to the making Experiments of Proposals for discovering the Longitude…. LONGITUDE, PARLIAMENT OF GREAT BRITAIN.
An Act for explaining and rendering more effectual Two Acts … with regard to the making Experiments of Proposals for discovering the Longitude…

An Act for explaining and rendering more effectual Two Acts… for discovering the Longitude…
An Act for explaining and rendering more effectual Two Acts … with regard to the making Experiments of Proposals for discovering the Longitude…

London: Mark Baskett, 10 January 1765.

Folio, title page, pp. 367-374, fine.

£3000 awarded to the widow of Tobias Mayer

An important Longitude Act, bringing John Harrison closer to reward but insisting the secret workings of his chronometers be revealed. Having outlined the successful sea trials during voyages to Jamaica and Barbados, this Act formalises the demand for Harrison to deliver the prototype H-4 and two identical operational copies of the chronometer (complete with diagrams) within a space of six months to be considered for the reward.

An important Longitude Act, bringing John Harrison closer to reward but insisting the secret workings of his chronometers be revealed. Having outlined the successful sea trials during voyages to Jamaica and Barbados, this Act formalises the demand for Harrison to deliver the prototype H-4 and two identical operational copies of the chronometer (complete with diagrams) within a space of six months to be considered for the reward.
Even at this stage only one half of the grand prize of £20,000 was on offer – with this payment being entirely contingent upon delivery of the timekeepers and working diagrams. For the remainder, the Act necessitates the improvement and supply of further chronometers and exhaustive testing before the balance will be paid, the 'other £10,000 to be paid when the other Time Keepers are made, and proved to be of sufficient Correctness'.
The original Act of 1714 allowed partial payment to persons who provided useful method for reckoning the longitude but did not formally qualify for the prize (as determined by an accurate bearing within half to one degree). Accordingly, this Act recognises the work of two Germans for their contribution to the lunar method: 'a set of lunar tables constructed by Tobias Mayer deceased, late Professor of Goetingen in Germany, upon the principles of gravitation laid down by Sir Isaac Newton; in the construction of which tables he was considerably assisted from theorems furnished by Professor Euler of the University of Berlin'. The Act directs £300 to be paid to Euler and £3000 to the widow of Tobias Mayer, upon condition that she submit the latest manuscript tables drafted by her deceased husband to the Commissioners.
Finally, the Commissioners are instructed to control all future publication of Almanacs by issuing licenses to publishers – with a hefty fine of £20 per copy for those who infringe the law.

Price (AUD): $2,250.00  other currencies     Ref: #3801453