Let the latitudes, on the same side of the equator, be 10° and 60°;
then the middle latitude and its complement are 35° and 55°, and half
the difference of the latitudes is 25°: and the difference of longitude
being 110°, the operation will stand as below.
Log. 6600´ (in 110°) 3.8195439
Constant log. -4.1015105
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-1.9210544
Log. sin. 35° -1.7585913
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S = ... -1.6796457
Again T = 1.4281480
_m_ = .4513202
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Log. (T + _m_) (= 1.8794682) 0.2740350
Log. (T - _m_) (= 0.9768278) -1.9898180
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Log. 0.2842170 = D = -1.4536500
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S - D (= log. tangent 59° 16´) = 0.2259957
agreeing to a minute with the solution by a table of meridional
parts.