Billingsley, Case, fl. 1714. *xDefoe The longitude at sea, not to be found by fir- 30 ing guns, nor by the most curious spring-clocks -714 or watches. But the only true method for discover- .BLOL ing that valuable secret by the sun, moon or stars, and an exact time-keeper, with such nec- essary improvements, as have not yet been des- erib'd by any other person; and (with respect to the term of any ordinary voyage) may properly be call'd a perpetual motion. ... By Case Billings- ley. (Continued on next card) MB