LET. X. OF THE LATITUDE AND LONGITUDE. l$g

LETTER

The same Subject continued.

NOT HER method for finding the longi-

'*■ titude of places, is by means of a chrono-meter, or an instrument for measuring time.This excellent machine, so useful in the commonaffairs of life, is capable of affording us infor-mation upon subjects which seem to have littleor no connection with it; but genius and in-dustry find analogies where vulgar apprehensionis blind. If a watch or clock could be so con-structed, as to measure time with accuracy andprecision, at all seasons, and in all places, suchan instrument might be used to discover thelongitude with the greatest ease and facility.

To illustrate this subject, we must consider themanner in which time is estimated. When thesun, in his apparent daily course round theearth, comes over any particular meridian, it isthen twelve o’clock, or noon, at all places whichlie under that meridian; but at all other places,it is either before noon, or after noon, accordingto their situation. The fun, moving from eastto west, must pass over the meridian NBS be-

fore