The object glass of the micrometer-microscope is placed midway between the plane of the photographic plate and the plane of the micrometer webs.
Spectrograph is the larger of the two it becomes necessary to adjust the object glass 0 1 farther C Ia from the stellar spectrograph.
Lxiii.) he showed how, by the deposition of a transparently thin film of silver on the outer side of the object glass of a telescope, the sun could be viewed without injuring the eye by excess of light.
The telescope must be focussed on the edge of the quartz plate, and in order that all points of the field may be illuminated by the same part of the source, the flame must be so placed that its image is thrown by the lens on the diaphragm of the object glass of the telescope.