iz8 OF THE LATITUDE AND LONGITUDE.

distance, • tempests and unknown currents in theocean, may occasion such irregularities as willrender it utterly impossible to ascertain thesituation of the vessel with any degree of pre-cision. So that before any estimation of thiskind, can be depended upon, it must be cor-rected, from time to time, by astronomical ob-servations.

This method of sailing by the stars, as it isfrequently called, may be traced back as far asthe time of Homer, and, perhaps, to a stillearlier period; but from the account which hehas given us, of the departure of Ulysses fromthe island of Calypso, it has been inferred, thathis knowledge of astronomy must have beenvery imperfect, since he describes the constella-tion of the great Bear as never setting, which isonly the cafe in certain latitudes.

Plac’d at the helm he fate, and mark’d the Ikies,

Nor clos’d in sleep his ever watchful eyes.

There view’d the Pleiads, and the Northern team,

And great Orion’s more refulgent beam,

To which, around the axle of the IkyThe Bear revolving, points his golden eye ;

Who Ihines exalted on th’ etherial plain,

Nor bathes his blazing forehead in the main.

Odyssey, E. V.

LET-