Admeasurement

1781, Thomas Jefferson, Notes on the State of Virginia, Query I By admeasurements through nearly the whole of this last line, and supplying the unmeasured parts from good data, the Atlantic and Mississipi are found in this latitude to be 758 miles distant, equal to 13° 38′ of longitude, reckoning 55 miles and 3144 feet to the degree.

Though the figures are similar, their angles, on admeasurement by a nice instrument, differ very appreciably.