[289] Let the first point of Gemini be on the meridian above the earth; the number of temporal hours since sunrise will then be 6, by which 17° 6′ 30″ are to multiplied. The product will be 102° 39′: this, added to 45° 5′, the aggregate number of the first point of Gemini in the latitude of Alexandria, will give 147° 44′, which, in the ascensions of the climate in question, will correspond to the 3d degree of Virgo, and show that to be the degree ascending. In the latitude of Southern Britain the total number would still amount to the same, viz. 147° 44′, but it would show 7° and about 30′ of Virgo to be ascending. But, in order to ascertain the degree on the meridian above the earth, the number of temporal hours since the preceding noon are also to be multiplied by their proper horary times, and the product is to be added to the aggregate number of the Sun’s right ascension; and that degree of the ecliptic, with which the total number as found in the aggregate times of right ascension shall correspond, will then be on the meridian.[290] The degree on the oriental horizon will, however, also show what degrees occupy the meridian; for, by subtracting 90 times (the amount of the quadrant) from the aggregate number ascribed to the said ascending degree in the Table proper to the climate, the number so reduced will be found, in the aggregate times of the Table of Right Ascension, to correspond with the degree on the meridian. And again, on the other hand, by adding 90 to the aggregate times ascribed by right of ascension to the degree on the meridian above the earth, the degree ascending may be obtained, for it will be that degree which corresponds to that total number, as stated in the Table proper to the climate.[291] The Sun always preserves an equal distance in equatorial hours from all parts of the same meridian; but his distance in equatorial hours from different meridians varies according to the degrees of distance between meridian and meridian. The foregoing extracts have been made to show the entire agreement between the astronomy of the Tetrabiblos and that of the Almagest. The Tables herein given from the latter work are, of course, now, in some degree, superseded by others of modern calculation, infinitely more complete. [290] Let the first point of Gemini be three temporal hours past the meridian; these hours reduced to degrees, in the latitude of Alexandria, will give 51° 19′, which, added to the right ascension of the first point of Gemini, make 109° 3′, showing the 18th degree of Cancer on the meridian. In the latitude of Southern Britain, these hours would produce 59°, which, added to the right ascension, would make 116° 44′, and show the 25th degree of Cancer on the meridian.