TABLE III. ROODS AND PERCHES IN DECIMAL PARTS OF AN ACRE. One Acre 4 Roods = 160 Perches 4,840 Square Yards=43,560 Square Feet. DECIMALS OF AN ACRE IN ONE CHAIN LENGTH OF 100 FEET, AND OF VARIOUS WIDTHS. TABLE IX. RADII AND THEIR LOGARITHMS, MIDDLE ORDINATES, AND DEFLECTION DISTANCES. NOTE. This table applies to chords of 100-feet units. To use it for chords of 20-metre units, divide the degree of the proposed metric curve by 2 and find the quotient in the first column of the table; or multiply any tabular degree of curve by 2 for the degree of the proposed metric curve. Then onetenth of the radius opposite the tabular degree thus found or assumed will give very nearly the true radius in metres of the proposed metric curve, and four-tenths of the corresponding figures in the last three columns will give very nearly the values of those functions in metric measure. Thus, if a 3° metric curve be proposed, we take one-tenth of the radius opposite the tabular degree 1° 30', or 382 metres, and find the values of the functions in the last three columns to be .1308, 1.048, and .524. Resulting errors may be neglected except in work of extraordinary accuracy. |