The sector and plain scale, compared. [electronic resource] : Containing I. The description of all the lines upon the sector and plain scales. II. The true use of the sector made plain and easie in several geometrical problems, and in all the cases of right lin'd trigonometry. III. All the proceeding geometrical problems, and cases of right lin'd trigonometry compared by the plain scale, and proved by Mr. Gunter's scale. IV. All the proceeding cases of right lin'd trigonometry, performed arithmetically, without the help of any sort of tables. Unto which is annexed, so much of decimal arithmetick, and the extraction of the square root, as is necessary for the working of arithmetical trigonometry. The second edition. By Roger Rea. N.P. Phi.