<P> John Harrison ( 3 April ( O.S. 24 March ) 1693 -- 24 March 1776 ) was a self - educated English carpenter and clockmaker who invented a marine chronometer , a long - sought - after device for solving the problem of calculating longitude while at sea . </P>
<P> John Harrison ( 3 April ( O.S. 24 March ) 1693 -- 24 March 1776 ) was a self - educated English carpenter and clockmaker who invented a marine chronometer , a long - sought - after device for solving the problem of calculating longitude while at sea . </P>
who solved the problem of longitude at sea
who solved the problem of longitude at sea
John Harrison
John Harrison