Copy 2

The description and use of ... Gunter's quadrant ... To which is added, the use of Nepiar's [sic] bones in multiplication, division, and extraction of roots ... / [William Leybourn].

  • Leybourn, William, 1626-1716
Date:
1731-1732
Catalogue details

Licence: Public Domain Mark

Credit: The description and use of ... Gunter's quadrant ... To which is added, the use of Nepiar's [sic] bones in multiplication, division, and extraction of roots ... / [William Leybourn]. Source: Wellcome Collection.

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    of the Sun, and AfcenGonal Difference as before, viz. 28 er. somin, this con- _ verted into Time, makerh. andabout 55min. and fo long did the Sun rife _ before fix, viz. at 4h. and 5 min. inthe Morning, and confequently fets fomuch _ after fix; and in the Winter, fo much as the Sun rifes after fix, fo much it _ fets before fix. Hence the Length of the Day and Night is moft eafily ob- tain’d ; for having the femidiurnal Arch, or lime from Sun-Rifing to Noon, °tis _ but doubling thofe Hours and Minutes, _ and you have the Length of the Day ; fo 7h. 55 min. doubled, is 15 h. 50 min. for the Length of the Day, May the 15th, which fubftracted out of 24h. remains 8h. 10min. for the Length of of the Night, ole S#cn