Letter From William Cooper On His Water Perambulator For Finding Longitude

[RichardB]

July 14th 1788 Carver Street, Sheffield.

Eyes not quite up to reading the thing obviously ...

Cooper

[Bayleaf]

Basically a speedometer for ships. Simple idea but takes no account of currents! Based on a waterwheel, he must have been watching one of the many wheels in Sheffield when he had his Eureka moment!