The Civil engineer and architect's journal, scientific and railway gazette (1839)
London : [William Laxton] · leaf 66
d an enlargement of the diameter of theobject-glass, so as, by the admission of a greater number of rays of light, toallow of the telescoir being shortened, without impairing its optical powers. A D is the telescope.—C C the compass-box.—M the screw for adjustingthe focus.—II II, the tubular… … Having thus endeavoured to describe the successive changes which thelevel has undergone, 1 shall now proceed to nolico the nature of the presen improvements. Tlie first of these is the substitution of a circular, or to speak more cor-rectly, a spherical level (G), sluggish in its motions, instead…
Architecture · Civil engineering · Science
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