object glass

Curiously the others crowded about the object glass of the periscope.

It contains a telescope made by Fitz, whose focal length is seventeen feet, and its object-glass is twelve and a half inches.

Any errors left over are to be attributed to other causes than the want of collinearity of the axes of object glass and eyepiece.

Each degree of my scale is equal, however, with the object glass employed, to .002 Mm.

We therefore proceeded with the experiment, and fixed into the object-glass the little animal, who was struggling in our tweezers.