Note 45 — THE THIRD VOYAGE NORTH-WARD TO THE KINGDOMES OF CATHAIA and China, in Anno 1596.
Reading edition
There is an error in the calculation here, which may be best explained by repeating the calculation itself, as it was doubtless made:—
33° 37′ Elevation of the sun.
23° 26′ Declination of the sun.
——— Elevation of the equator, which being the complement of the elevation of the Pole, had to be deducted from 90°.
10° 11′
90° 0′
———
80° 11′
———
But in making the deduction, the 11′ were carried down instead of being subtracted from 60′; and then, of course, 90° - 10° = 80°. The true difference is 79° 49′, which is, consequently, the latitude observed. ↑