Hind, H. Lloyd (Herbert Lloyd), Randles, W. Brough (William Brough) · London : G. Routledge & sons, ltd · leaf 301
185 DARK GROUND ILLUMINATION … . Fig. 59 COURSr OF RAYS IN LEITZ’ DARK GROUND ILLUMINATOR In order that the rays, which, as indicated in the figure, are very obhque, shall not suffer total reflection at the under surface of the slip, the latter is always oiled to the condenser. The light consequently passes through to the…
Color photography · Photomicrography
Internet Archive · Wellcome Library · Public domain (published before 1931). Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer03inte-380-238.webp)
