In Table XVI. of Mr. Baily, the Equation of equal Altitudes is given for the entire interval of 24 hours, but it is seldom required beyond the above limits. R TABLE XV. LENGTH OF A SECOND OF LATITUDE AND LONGITUDE IN FEET ON THE SURFACE OF THE EARTH, THE COMPRESSION BEING TAKEN AS 30. Puissant, calculating the compression from the measurement of the great arc in France, obtains different results on different sides of the Meridian of Paris, making it as low as 26 on the side of the Atlantic, and 305 to the Eastward; which latter quantity is generally 250 assumed on the Continent. TABLE XVI. CORRECTIONS FOR CURVATURE AND REFRACTION. Showing the difference of the Apparent and True Level in Feet, and Decimal parts of Feet, for Distances in Feet, Chains, and Miles. Correction in Feet. For Refraction. For Curvature and Refraction. Correction in Feet. 2.000042 00006 00036 3 8-1708 1.1673 10.6720 1.5246 13.5468 1.9295 5 16.6750 2.3821 14-2929 520-1769 7.0035 9.1474 11.5773 2.8824 17-2945 3.4303 20-5817 6 7 20000096 00013 00083 50 00261 0003700224 3 24-0120 28.1809 4.0258 24.1551 32.6830 4.6690 28.0143 37-5190 5.3599 32-1591 42.6880 6.0997 36-5883 48-1910 6.8844 41.3066 54-0270 7.7181 46.3089 60-1971 8.5996 51.5975 66.7000 9.5286 80-7070 11.5296 96.0480 13-7211 112-7230 16-1033 96.6197 130-7320 18.6760 112-0560 150-0750 21.4393 128.6357 57.1714 69-1774 82.3269 170-7520 24-3931 146.3589 192-7630 27.5376 165.2254 216-1086 30.8727 185.2359 240-7870 34-3981 206-3889 266-8000 38.1143 228-6857 TABLE XVII. REDUCTION IN LINKS AND DECIMALS UPON EACH CHAIN'S LENGTH FOR THE FOLLOWING VERTICAL ANGLES. TABLE XIX. COMPARATIVE SCALE OF FAHRENHEIT'S, REAUMUR'S, AND THE CENTESIMAL THERMOMETERS. The following formula will serve for the comparison of these Thermometers. The Logarithms answering to every degree of the graduations of the above Thermometers will be found at page 296, vol. i., of Dr. Pearson's "Practical Astronomy." |