174 0k TH £ LATITUDE AND LONGITUDE.

liamentary reward, offered for the discovery ofthe longitude; but as it was judged to be de-fective, his hopes were disappointed, and hisinvention of course neglected.

Such are the difficulties with which this im-portant subject is perplexed and embarrassed,that all the* resources of art and genius havehitherto been ineffectual to remove them. Byapplying to the heavens, however, we haveanother method afforded us, which, althoughit be attended with some difficulties, is thatin which astronomers at present have the greatestconfidence, and hopes of success. This methodis likewise derived from observations on themoon, not when she is eclipsed, but at any timewhatever, when she is visible above the horizonof the place where the observations are to bemade. Eclipses of the moon happen too seldomto be of any great service at sea, and the planetJupiter is, for a great part of the year, invisible;but the moon is almost continually offering her-self to our view. This method, therefore, ap-pears to be better adapted to general use thanany that has yet been discovered.

The moon rises about three quarters of anhour later every day than upon the precedingone ; and as she changes her place considerably,from day to day, among the stars, these changesbecome proper for determining the longitude.If, for instance, the moon be observed to day tobe near any fixed star, she will appear to-morrow,

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