The sea-man's practice, containing a fundamental problem in navigation, experimentally verified; namely, touching the compass of the earth and sea, and the quantity of a degree in our English measures. Also, an exact method or form of keeping a reckoning at sea in any kind or manner of sailing. With certain tables and other rules useful in navigation. As also in the plotting and surveying of places. The latitude of the principal places in England. The finding of currents at sea, and what allowance is to be given in respect of them. The tenth edition. By Richard Norvvood, reader of the mathematicks.