The description and use of the universall quadrat.: By which is performed, with great expedition, the whole doctrine of triangles, both plain and sphericall, two severall wayes with ease and exactness. Also the resolution of such propositions as are most usefull in astronomie, navigation, and dialling. By which is also performed the proportioning of lines and superficies: the measuring of all manner of land, board, glasse; timber, stone. &c.
Stirrup, Thomas.
CHAP. XI. Having the amplitude and declination of the Sun, to finde the elevation of the Pole above the Horizon.
- AS the sine of the Amplitude,
- To the sine of the declination:
- So is the radius,
- To the cosine of the latitude.
Thus in the right angled Triangle ♈QT, in the Dia∣gram of the 6 Chap. having the Amplitude the base ♈T, 19 deg. 7 min. and the side TQ, the declination of the Sun 11 deg. 30 min. with the right angle at Q, we may Page 162 finde the complement of the Latitude the angle T♈Q, by the 30 Chap. of the second Book.
For if we place the threed at the intersection of the contrary sine of 19 deg. 7 min. with the right sine of 11 deg. 30 min. it will cut the contrary sine of 90 deg. at the right sine of 37 deg. 30 min. and such is the comple∣ment of the Latitude the angle T♈Q, which being taken out of 90 deg. leaveth 52 deg. 30 min. for the angle P♈B, the elevation of the pole above the horizon which was required.
