Machinery and processes of the industrial arts, and apparatus of the exact sciences (1869)
Barnard, Frederick A. P. (Frederick Augustus Porter), 1809-1889 · Washington, Govt. print. off. · leaf 606
ement, whichrenders it much more commodious in use than it was in its original form.The instrument consists of two prisms of observation, connected by ameasuring tape or chain which serves to determine the length of thebase on which the parallax is to be ascertained. These prisms are suit-ably… … Prism Telemeter. prisms are four-sided, the reflecting sides, which are silvered, being at anangle of forty-five degrees to each other, so that a ray which enters at a,after two interior reflections emerges at d, at right angles to its originaldirection. The prisms are inclosed in the boxes marked…
Machinery · Scientific apparatus and instruments
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer04inte-451-221.webp)
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten15unit-779-419.webp)
