ftET. X. OF THE LATITUDE AND LONGITUDE. f

nted to;n it isI look-

a places west•eciselyuncer-lian it

ng the

ude ofuator jd thatude, isre the

othertime-aritieswouldsservas what; eveiy>f persubject:•egulart tem-mates,must.

must, in particular, affect: it considerably, andoccasion errors which seem to admit of no ade-quate remedy.

It must be observed, however, that a greatdeal more has been done in this way than couldpossibly have been expected. That excellentartist, Mr. John Harrison, considered the sub'-ject with an indefatigable and unwearied atten-tion ; and his inventions for removing the im-perfections to which clock-work in general isliable, appeared to the commissioners of longi-tude so deserving of encouragement, that theyallowed him several considerable gratuities, toenable him to bring his ideas to perfection.From a trial of his watch, made in the years1761 and 1762, in a voyage to Jamaica, it wasfound to have erred only 1 minute and 54 se-conds in about five months; and in anothervoyage to Barbadoes, the mean daily error wasabout 2 \ seconds; for which discovery, as itcame within the meaning of the act, the com-missioners ordered him the sum of jo,oool. Andsome time afterwards, in consequence of his ex-plaining the principles of his time-keepers, insuch a manner as to enable others to make themwith the fame accuracy, he received the remain-ing moiety of the parliamentary reward.

Whilst Mr. Harrison was prosecuting thissubject in England, Messrs Le Roy, Berthoud,&c. were engaged in the fame pursuit in France;

M 3 and