Transactions . at-tached to the theodolite; and this arrangement is very effective, * Trans., xxix., 962. t Trans., xxix., 964. i;i:m LRKS ON MINE-SI i;\ \ \ [NG [NSTR1 MEN I 3. 81 and a complete remedy for all such defecte and Lnconvenien feel pointing to the sky, and with the plate- fallen apart downwards in regu-lar order. Fig. 14(>, copied from Troughton & Simms Cata-logue of 1900, shows the whole apparatus right side up, as in Fig. Shifting Tripod-Head, Bottom-Plate, Inverted. use. The plate of Fig. 137 has a narrow slit about an inchlong through it near each end; and a short, sh
Transactions . at-tached to the theodolite; and this arrangement is very effective, * Trans., xxix., 962. t Trans., xxix., 964. i;i:m LRKS ON MINE-SI i;\ \ \ [NG [NSTR1 MEN I 3. 81 and a complete remedy for all such defecte and Lnconvenien feel pointing to the sky, and with the plate- fallen apart downwards in regu-lar order. Fig. 14(>, copied from Troughton & Simms Cata-logue of 1900, shows the whole apparatus right side up, as in Fig. Shifting Tripod-Head, Bottom-Plate, Inverted. use. The plate of Fig. 137 has a narrow slit about an inchlong through it near each end; and a short, shouldered metalpin moves freely in each slit, and likewise fits into and movesfreely in a corresponding slit near each end of the plate of , that, in use, rests upon the plate of Fig. 137. The slitsof Fig. 138 are cut at right angles to those of Fig. 137; con-sequently the plate of Fig. 138 moves freely in two directions,at right angles one to the other, while both plates are held to-gether by the shouldered metal pins. The large hole in thecenter of the plate of Fig. 137 has a female screw inside of it,and screws fast upon a corresponding male screw on the top ofthe tripod-stand head. To the upper side of the plate a hollowthin cylinder is cast, projecting upwards, with a male screw cutupon it. This projecting male screw passes through the large 32 REMARKS ON MINE-SURVEYING INSTRUMENTS. central hole in the plate of Fig. 188 above;
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
