Description of a new transit instrument / improved by Sir H.C. Englefield ... and made and sold by T. Jones.

  • Englefield, Henry, Sir, 1752-1822
Date:
1814
Catalogue details

Licence: Public Domain Mark

Credit: Description of a new transit instrument / improved by Sir H.C. Englefield ... and made and sold by T. Jones. Source: Wellcome Collection.

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    HISTORICAL. I medical / 1 DESCRIPTION, Ac‘ Several years have now elapsed since f first thought of the arrangement for this instrument ; but though I obtamed a patent for it about two years ago, I have till now been prevented from submitting it to the public by various pro- fessional duties which I could not lay aside f being obliged, like every man who tries to attain excellence in his pro- fession, to finish the greater and most particular parts of my instruments with my own hands. The sectograph will, 1 hope, effect the purposes intended; namely, a considerable saving of time, and a degree of ac- curacy applicable to the various purposes of drawing. The instrument is very simple in its construction, and easy in its use ; requiring only one setting or adjustment for divid- ing, laying down, or measuring any space or angle ; and with a facility Calculated to lessen the laborious part of these processes, and to render them light and pleasant to the careful and elegant draughtsman. The common size of the sectograph is about eight inches long, and measures to the extent of that distance. The instrument is packed in a morocco case (with a printed de- scription inside) the exterior of which is about nine inches long, and three quarters of an inch square*. jDescription of the Instrument. The bars of metal (or other substance) (PI.VI.) A,H,B, are of equal dimensions, the bars a, a, a,«, cr, are likewise equal to each other. The whole of the eight bars are of the same length, and are pinned and screwed together at the dots and small circles, where the ends of the smaller bars join the larger; each joint giving an easy and pleasant motion. 1,3, 5, and 7 are small short pieces placed across, and pinned to the others. 0, 1, 2, 3, 4, 5, 6, 7 and 8 are the places where the steel points are fixed into the bars. e,g, is a scale with a slit in the middle, which receives the clamp and fixing screw n, for holding the points at any required di- * The pi ice of the eight-inch is two guineas, that of others in properties to their lengths, &c. as they are made to any size, with any number of points, or without the clamp and scale, if required. stance,