orexample,in the position of the All these modifications can be easily introduced into tinguishing objects at a distance with great distinct-|rose represented in Fig. 3 we read 8. E.—E. 17 grades. | the ordinary field glass. The instrument under con- ness. This apparatus is much used by our… … action of the spring, F, and of setting the rose rection relative to the magnetic declination is free. The pivot and the compass are inclosed THE COMPASS FIELD GLASS. made, and, consequently, the geographical in a box, B, placed in the field glass, usually meridian is confounded with the magnetic.…
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