Thesaurarium mathematicae, or, The treasury of mathematicks containing variety of usefull practices in arithmetick, geometry, trigonometry, astronomy, geography, navigation and surveying ... to which is annexed a table of 10000 logarithms, log-sines, and log-tangents / by John Taylor.

PROP. I. How to Tertiate, Quadrate, and to Dispart a Piece of Ordinance.

1. To Tertiate a Piece, is to find whether it hath its due thickness at the Trunnions, Touch∣hole, and Neck; if the Trunnions, and the Neck are in its due order, and the Chase streight.

2. To Quadrate a Piece mounted, is to see whether it be directly placed, and equally poi∣zed in the Carriage; which is known by find∣ing in the Convex Superficies of the Base, and Muzzel Ring; the point which is Perpendicular, over the Soul of the Piece which may be found by the Gunners Instrument, called a Level; an Instrument whose use is so vulgarly known, that it needeth not my Explanation.

3. To Dispart a Piece, is to fix, or elevate on the Convex point of the Muzzel Ring, a Mark, as far distant from the Cylinder, or Soul of the Piece, as is the point of the Base-Ring; to the end, that the Visail-ray which passeth by these marks, may be Parallel to the Chase, Soul, or

Cylinder of the Piece. Now the Dispart, i. e. the difference of the Semidiameters of the Cor∣nishes, may be by a pair of Calliper Compasses at∣tained. Which found, place on the Top of the Cornish-Ring, near the Muzzel, over the mid∣dle of the Inferior Cylinder.