A Collection of Tables and Formulæ Useful in Surveying, Geodesy, and Practical Astronomy: Including Elements for the Projection of Maps |
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Common terms and phrases
Ascension in Arc axis azimuth Barometer 30 Inches Cedar Point Chronometer Co-ordinates collimation comparison of French compute correction corresponding decimal point declination Decm deflecting magnet degree Diff English Barometers English feet English inches equal altitudes Equations to Equal Equator in Arc formula found by moving French and English horizontal intensity hour angle instrument Intermediate minutes length limb Log B.
H. M.
H. M. longitude Longitude in Arc magnetic moment mean moon Mean R. A. mean solar meridian Meridional Arcs-Values metre miles Millime Millimetres minutes and seconds moon's moving the decimal noon Obs'd less parallax parallel Parallel-Values quantities R. A. in Arc Reduction refraction Right Ascension scale Sextant sidereal day spherical excess star station Sun's suspended magnet Table tang tang L telescope Theodolite tion toises transit tres Troughton & Simms value Lat vibration Yards zenith distance бр
Popular passages
Page 26 - To trace Railroad Curves by means of deflections. General Propositions. 1. The angle formed by a tangent and a chord is equal to half the angle at the centre of the circle, subtended by the chord. 2. The angle of deflection formed by any two equal chords meeting
Page 8 - is a vessel containing 58372.2 grains, (8.3389 pounds avoirdupois,) of the standard pound of distilled water, at the temperature of maximum density of water, the vessel being weighed in air in which the Barometer is 30 inches at 62° Fahrenheit. The bushel is a measure containing 543391.89 standard grains (77.6274
Page 10 - 10 pounds avoirdupois weight of distilled water, weighed in air at the temperature of 62° Fahrenheit's Thermometer, the Barometer being at 30 inches. The
Page 6 - Oblique spherical triangles sin A sin B sin C sin a ~~ sin b sin c cos a = • cos b
Page 8 - The bushel is a measure containing 543391.89 standard grains (77.6274 pounds avoirdupois) of distilled water, at the temperature of maximum density of water, and Barometer 30 inches at 62° Fahrenheit. The gallon is thus the Wine gallon (of 231 cubic inches) nearly, and the bushel the Winchester bushel, nearly. The temperature of maximum density of water was determined by Mr. Hassler to be
Page 8 - are the gallon for liquid and the bushel for dry measure. The gallon is a vessel containing 58372.2 grains, (8.3389 pounds avoirdupois,) of the standard pound of distilled water, at the temperature of maximum density of water, the vessel being weighed in air in which the Barometer is 30 inches at 62°
Page 54 - in yards = 6.8427917. If the three angles of a triangle are assumed to have been equally well determined, the previous determination of the spherical excess is not necessary for the calculation of the sides, though it will be required for estimating the relative accuracy of the observations. For the sides of a spherical triangle may be computed as if they were rectilineal, when
Page 56 - to the level of the sea. Let r represent the radius of the Earth (or better, the normal N,) corresponding to the base b at the level of the sea, and r -\- a the radius referred to the level of the measured base B,
Page 54 - Between latitudes 45° and 25° the spherical excess amounts to about 1" for an area of 75.5 square miles. Hence, if the area in square miles be known, a close approximation to the spherical excess will be had by dividing the area by 75.5.
Page 23 - to that which is formed in excavations or embankments of roads ; terminated by parallel cross sections. Solid content = area of each end, added to four times the middle area, and the sum multiplied by the length