The dictionary of photography for the amateur and professional photographer (1897)
Wall, E. J. (Edward John), 1860-1928, Bolas, Thomas · London : Hazell, Watson & Viney · leaf 65
Astronomical Photography bench should ordinarily be a rough, heavy table kept out of doors, a recess in the bench and thumbscrew for each foot being sufficient ; and care should be taken that when the stand is in its place the pillar is vertical. A position b is now found on the meridian line b c,… … Fig. 8. angle a b c equal 51° 30', and a worker in Edinburgh would make it equal 560. A cord is now attached to the telescope at the object glass and passed through the hole b, this cord being kept conveniently tense by a weight D, which weight should not be so heavy as to interfere with the free…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
