Gurley Civil Engineers' and Surveyors' Instruments 1896 (1896)
W. and L. E. Gurley · leaf 45
about three inches wide, at the ends of which are screwed sight-vanes, like those of the ordinary compass; one edge of the ruler being chamfered and in line with the slots of the vanes. No. 581. | Price, $50.00. {i == No. 581 shows the simple Alidade to which is fitted the telescopic sight, having… … In the Alidade shown in No. 583, the telescope is precisely the same as that used on our best Transits, being also supplied with the level, clamp and tangent, vertical circle on silver reading to single minutes, and micrometer wires for measuring distances. ¢ It is placed on a brass ruler about…
