200 b Tie Peſeription o Lines.

The Croſi dec to it is 26 Inches between the to outwardſights, If any would have it in a greater form, the proportion betweenthe Staff and the Croſs, may be ſuch as 3 ë unto 262.

The Lines inſcribed on the Staff are of four ſorts: One of themſerves for Meaſure and Protraction: One for obſervation of AnglesOne for the Sea- Chart; and the four other for working of Proporti-ons in ſeveral kinds. g

The Line of Meaſure is an Inch Line, and may be known by kisequal quarts, the whole Vard being divided equally into 36 Inches,and each Inch ſubdivided firſt into ten parts, and then each tenth partinto half: g n

The Line for obſervation of Angles may be known by the doubleNumbers, ſet on both ſides of the Line, beginning at the ſide at 20,and ending at 90: on the other ſide at 40, and ending at 180 andthis being divided according to the degrees of a quadrant, I call ie theTangent Line on the Staff. f i

Ihe next Line is the Meridian of a Sea chart, according to Merca-2076 Projection from the Equinoctial to 58 g. of Latitude, ànd may beknown by the letter A, and the Numbers 1, 2, 3, 4, unto 38.

The Lines for working of proportions may be known by cheir un-equal diviſions, and the numbers àt the end of each Line.

. The Line of numbers noted with the Eetter N, divided unequal·ly into ooo parts, and numbred with 1, 2, 3, 4, unto 10.

2. The Line of Artificial Tangents is noted with the letter T, divi-ded unequally into 45. degrees, and numbred both ways, for the Tan-gent and the Complement. N

3. The Line of Artificial Sines noted with the letter 8, divided un-equally into 90 degrees, and numbred wirh 1, 2, 3, 4, unto 90.

4. The Line of Verſed Sines for more eaſie finding the heur andAzimuth, noted with V, divided unequally into about 164 fr. 80.numbred backward with 1 e, 20, 30, unto 164. g

Thus there are ſeven Lines inſcribed on the Staff: there zre FiveLines more inſcribed on the Croſs. 8

1. A Tangent Line of 36 gr. 3 m. numbred by 5, 10, 18, unto 35;

ehe midſt whereof is at 20 fr. and therefore I call ie the Tangent of20 5 and this hath reſpect unto 20 gr, in the Tangent on the Staff.

2. A Tangent Line of 49 gr. d. numbred by 5, 10, 1 5, unto 453the midſt whereof is at 30 gr and hath reſpect unto 30 gr. in the Tan-gent on the Staff, whereupon I cell it the Tangent of 30. n

3. A