A mathematical manual: or, delightful associate ... Published for the contemplation and diversion of gentlemen, and others, who are mathematically inclined / By E. Hatton, gent.

  • Hatton, Edward, 1664?-
Date:
1728
Catalogue details

Licence: Public Domain Mark

Credit: A mathematical manual: or, delightful associate ... Published for the contemplation and diversion of gentlemen, and others, who are mathematically inclined / By E. Hatton, gent. Source: Wellcome Collection.

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    Sun rifes. Sun fits. Length of Day. Length of Night. h. 9 hi * h. h. Jan. 1. 8—oq 4—06 08—00 l6-OO Apr. i. 5—21 6—39 13—18 c* -r l 0 M Nov. 4. 7—40 4—20 O rt* 1 00 O M V* ! O Dec,25. 8—02 1 00 O 1 ©\ 16—04 PROS, IX. jfo find the T,me of Day-Break, and End of ifwy-light. sfhis is when the Sun is eighteen Degrees below the Horizon, before its Kifing, and after its Setting. RECTIFY the Globe as to Latitude, and the Quadrant of Altitude fcrew’d in the Zenith; then (for Day-Break) firft find the Sun’s Place in the Ecliptic, and bring that to the Meridian, and the Hour Index to 12; then bring the De¬ gree of the oppofite Sine to the Meridian, and move the Ball and Quadrant of Altitude on the Weft Side of the Meridian, till the Degree of the oppofite Sine fall juft under 18 Degrees of the Quadrant of Altitude , then the Index will cut the Time of Day-break in the Hour- Circle. 1? A < And