An essay on electricity. Explaining the principles of that useful science : and describing the instruments, contrived either to illustrate the theory, or render the practice of entertaining / by George Adams.

  • Adams, George, 1750-1795.
Date:
1792
Catalogue details

Licence: Public Domain Mark

Credit: An essay on electricity. Explaining the principles of that useful science : and describing the instruments, contrived either to illustrate the theory, or render the practice of entertaining / by George Adams. Source: Wellcome Collection.

    600/618 (page 582)
    Plain {cales and fetors of different fizes Square protractors, femicircular and circular Magazine, or complete colle&ion of diawing in- ftruments, at 11]. 118. at 17l, 17s. and from thence to Medison Oth Wa) 50 Perfpeétive compaffes for afcertaining the relative proportion of objects - i ages Ate: ° A new invented inftrument for taking views, &c. which will facilitate the operations of the artift, and greatly affift beginners 3 A ditto for drawing on an horizontal plane is Pantographers for copying, reducing, and enlarg- 6 ing drawings, from 2l. 12s. 6d, to Surveying Inftruments, Gafes of drawing inftruments, — Parallel rules, — Plotting fcales.— Sets of plotting fcales.—A new-invented parallel rule, with plotting fcales. —A parallel rule and protrattor A plotting {cale, in form of a beam compafs Protra€tors for laying down ang!es Ditto with anonius and moveable limb ore | Ditto rendered more accurate, as the limb 1s made Mealuring wheels — 6 Pedometers for mealuring a given diftance in walking Meafuring chains pf 50 and 100 feet Gunter’s chain — Tape boxes, according to the length Surveying crofs or fquare r- rt ae Plain tables, with an index and fights; by thefe the planis taken on the fpot, and does not require a future protraction — — Beighton’s improved plain table, with an index of a peculiarmake; in this inftrumentthe line of fight is always over the center of the table, the {tation lines are alfo drawn parallel to thofe meafured on the ground 7 a ° 1 14 $. ae 15 6 9. 19 18 fe) 3 0 5 oO 6 0 12 6 14 6 16 6 7 6 11 6 13 6 140