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Show A. 1. '50:: SUGGESTIONS ON USE OF TABLES. ~ ".7 my... (I; '3 '5. -‘. ~ ‘TABLES SUGGESTIONS TO YOUNG SURVEYORS ON THE USES OF .~_-. v- Lfiz‘fi‘i'fl "w : Eur-1 5.; . f 4 ‘i‘ ti _ _.., "a... w » ~< _ v -}f' THE TABLES. Traverse Table.-The table calculated to quarter degrees is adapted to the simplest work of compass surveying, Where great accuracy is neither required nor expected. When the transit is used, and the angles are taken to minutes or less, the author prefers the tables of logarithms and logarithmic sines and cosines to any traverse table yet made. They are capable of any required degree of accuracy, and require the use of no more figures than the ordinary traverse table. In transit work, where latitudes and departures are to be calculated, it is well to refer the angles of all lines to a common base, if as in compass surveying all lines are referred to the - ridian as a base. Then, in any course, Latitude = co-sine of angle >< length of the course. Departure =‘sine of angle X length of the course. Using the logarithmic tables, this is a short and simpl e computation. Example Irv-Angle, 36° 22'. the latitude and departure. Distance, 47.63. Required Log. of 47.63 = 1.677881 to which add log. sine, 36° 22' = 9.773018 " _ 11.450899 the log of 2824+ = departure. .Log. of 47.63 = 1.677881 to which add log. cos., 36° 22' = 9.905925 11.583806 the log. of 3833+ = latitude. 2. Course N. 57° 21' 20" E. 34.36% chains. the latitude and departure. Required;' |
