Natural of the Difference S I 32,00035 V. Sine of theSun's Dift.from thePole67 54 562377 The Log. of which Difference,6234.2 with the Square of the Radius, is Cofine of the Altitude 50 00 51° 32' O 40 00 38 28 ,62342 29,794780 9,793831 9,808097 Sum fubtract 19,601898 Remains 10,192882 Here the Remainder exceeds 10,000000; wherefore cancel the Characteristic 10, and the Number anfwering the remaining Logarithm is 1,5591; the Excefs of which above Unity, viz.,5591, gives the natural Sine of 34° 00'; whence the Sun's true Azimuth is North 124° 00' Weft: At which Time, if the Sun's Magnetical Azimuth were North 110° 30' Weft, the Variation of the Compafs would be 13° 30' Weft, as appears by the following Subtraction. True Azimuth North, 124° 00′ West Variation 13 30 West 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; which in Practice creates no more Trouble than when the Declination is North, if fo much; fince it is at leaft as easy to take the natural Sine of an Arc, as to take the Versed Sine of its Complement to 90 Degrees; which Sines, and others, with their refpective Logarithms, c. may readily be had out of Sherwin's Mathematical Tables. FINI S. BOOKS printed for W. STRAHAN, J. and F. RIVINGTON, HAWES, CLARKE and COLLINS, W. JOHNSTON, T. LONGMAN, T. CADELL, T. DAVIES, T. BECKET, G. ROBINSON, and R. BALDWIN. E UCLID'S ELEMENTS, Vol. II. Containing the Seventh, Eighth, Ninth, Tenth, Thirteenth, Fourteenth, and Fifteenth Books; with the DATA: Being the remaining Part of that Work, which were not published by the late Dr. Keill, now first tranflated from Dr. Gregory's Edition. To which is prefix'd, An Account of the Life and Writings of EUCLID; with a Defence of his Elements against the modern Objections. By Edmund Stone, F. R. S. An Appendix to the English Translation of Commandine's EUCLID; wherein the Eleventh and Twelfth Books of the Elements are made easy to the meanest Capacity, by exhibiting the Solids themselves to the Eye, instead of their feveral Pictures or Projections laid down by the several Writers of Elements of Geometry. A Tract useful and neceffary for Painters, Builders, Gardeners, and all Perfons who would inform themselves demonftratively in Perfpective, Menfuration, Spherics, &c. or qualify themselves to read the Works of thofe who have written farther on folid Geometry. With an Introduction explaining the Projection used by the Antients, and fhewing its Excellency to any other for this Purpose. By Samuel Cunn. |