Elements of geometry / from the Latin translation of Commandine. To which is added, a treatise of the nature of arithmetic of logarithms, likewise another of the elements of plain and spherical trigonometry; with a preface ... By Doctor John Keil ... The whole revised ... [with a] preface, by Samuel Cunn.

  • Euclid
Date:
1741
Catalogue details

Licence: Public Domain Mark

Credit: Elements of geometry / from the Latin translation of Commandine. To which is added, a treatise of the nature of arithmetic of logarithms, likewise another of the elements of plain and spherical trigonometry; with a preface ... By Doctor John Keil ... The whole revised ... [with a] preface, by Samuel Cunn. Source: Wellcome Collection.

    454/465 (page 397)
    From the Com. of the Altitude Sub. the Com. of the Latitude Natural C of the Difference— 4c0 : oo/ 28 : 28 - 1 _ 32—500035 V. Sine c oftheSun’sdift. fromthePoleo7: -54—,62377 562342 S 29^704.780 Cofine of the f *f?ttitu,de 32' “ ~ £ Altitude 50 00 —- The Log. of which Difference 62342 with the Square of the Radius is 9.793831 9.808067 Sum fubtrad 19 601899 Remains 10.192882 Here the Remainder exceeds 10,0000003 wherefore cancel the CharaCteriftic 10, and the Number an- fwering the remaining Logarithm is 1,55913 the Ex- cefs of which above Unity,m. ,5591, gives the natu¬ ral Sine of 34* oo' 3 whence the Sun’s true Azimuth is North 124® 00' Weft. At which time, if the Sun’s Magnetical Azimuth were North iig° 30' Weft, the Variation of the Compafs would be 130 30' Weft, as appears by the following Subtraction. True Azimuth, North 1240 : oo' Weft Mag. Azimuth, North no 30 Weft Variation 13: 30 Weft N. B. If the Sun’s Declination had been South, then the verfed Sine of the Sun’s Diftance from the elevated Pole, would have been equal to Unity plus the natural Sine of the Sun’s Declination 3 which in Practice creates no more Trouble than when the Declination is North, if fo much 3 fince it is at leaft as eafy to take the natu¬ ral Sine of an Arc, as to take the verfed Sine of its Complement to 90 Degrees3 which Sines, and others with their refpeCtive Logarithms, <&c, may readily be had out of S her win’s Mathematical Tables. F I N. I i ' t * 397 • • •*