Spon, Ernest, Haldane, Robert, Lock, Charles G. Warnford (Charles George Warnford), 1853-1909 · London ; New York : E. & F.N. Spon · leaf 436
anging Drop-Shutters for a varietij come weakened by keeping. of Lenses. — It is often annoying, when Care should be taken not to add too wishing to use difiereut lenses for instan- much dilute acid to the hypo at a time, taneous exposures, to find that each else excessive elTervoscence will occur,… … ])hragms, in order to obtain the greatest rapidity com- Fio. 231. bined with the least pos- ,(V sible distance to travel. On the axis to which this cir- -a- cular disc is fixed is a small 0= ^?"^ wheel, to which is attached a ])iece of string, and when the disc is turned round for the exposure the…
Workshop recipes · Technology · Industrial arts
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer03inte-637-380.webp)
