This is the ACTUAL patent issued to Peter Litherland in 1792! The documents include the original Principal Letters Patent 1792 under seals of George III of Great Britain and Ireland and a handwritten certificate on watermarked paper from David Ewart, clerk to the Chancery of Scotland, addressed personally to Peter Litherland. The documents are still housed in their original leather patent boxes.
The patent was granted to Peter Litherland at the "Chancery of Scotland" on the 2nd March last ...sic...30th June, 1792". There are four "animal parchment" patent documents which detail as Latchford wrote "an entire escapement to be applied to watches... for sea or land...producing greater certainty of time than hither to invented being more simple and less likely to be out of repair...especially for ascertaining the longitude at sea at much less expense than those now used". These documents are the patent of "The Rack-Lever Escapement; a beating seconds & keyless winding work".
QUESTIONS:
Under British patent law, these documents would grant Litherland the right to the rack lever design and production for 14 years. So this would mean that no other watchmakers could produce a rack lever until 1806 without a written agreement with Litherland. One of the most famous and prolific rack lever watchmakers was Robert Roskell whose shop was next door to Litherland's.
1) When did Robert Roskell start producing rack levers?
2) If it was before 1806, did he have a written contract with Litherland to pay him royalties? Or did Roskell only start producing rack levers after expiration of Litherland's patent in 1806?
3) Did Litherland produce rack levers for retailers and other watchmakers during the period of his patent?
R/
Chris
Photos can be found here Full Lot Details (henry-aldridge.co.uk)
The patent was granted to Peter Litherland at the "Chancery of Scotland" on the 2nd March last ...sic...30th June, 1792". There are four "animal parchment" patent documents which detail as Latchford wrote "an entire escapement to be applied to watches... for sea or land...producing greater certainty of time than hither to invented being more simple and less likely to be out of repair...especially for ascertaining the longitude at sea at much less expense than those now used". These documents are the patent of "The Rack-Lever Escapement; a beating seconds & keyless winding work".
QUESTIONS:
Under British patent law, these documents would grant Litherland the right to the rack lever design and production for 14 years. So this would mean that no other watchmakers could produce a rack lever until 1806 without a written agreement with Litherland. One of the most famous and prolific rack lever watchmakers was Robert Roskell whose shop was next door to Litherland's.
1) When did Robert Roskell start producing rack levers?
2) If it was before 1806, did he have a written contract with Litherland to pay him royalties? Or did Roskell only start producing rack levers after expiration of Litherland's patent in 1806?
3) Did Litherland produce rack levers for retailers and other watchmakers during the period of his patent?
R/
Chris
Photos can be found here Full Lot Details (henry-aldridge.co.uk)
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