Instructions concerning the use of pendulum-watches, for finding the longitude at sea
Abstract
Whereas 'tis generally esteemed that there is no practise for the finding of the longitude at sea comparable to that of those watches, which instead of a ballance-wheele are regulated by a pendulum, as now they are brought to great perfection, and made to measure time very equally; and many perhaps here as well as elsewhere being not well versed in the ordering and managing of that instrument:

