Geo-met′ric square.
An instrument for measuring distances and hights, and useful for its portability as well as for the facility, by the common rule of three, of solving most of the problems arising from its use. It is made of brass or wood, 12 or 18 inches square, and the quadrant is graduated in each direction.
The two sides opposite to the axial point of the alidade are graduated to 100 equal parts, with major divisions of ten of said parts.
The 100 point finishes at the angle obliquely opposite the center from which the are is struck.
One side represents the horizon, and the alidade with two sights is equal in length to the diagonal of the square.
The alidade has divisions equal to those on the sides of the square.
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Geometric square. |
In measuring vertical hights, the distance is
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964]
measured from the station to the base, and by moving the alidade the angle subtended by the object is observed.
