ROYAL ASTRONOMICAL SOCIETY / SCIENCE PHOTO LIBRARY ROYAL ASTRONOMICAL SOCIETY / SCIENCE PHOTO LIBRARY
Telescope stands. These stands are for achromatic telescopes and micrometers, and are by the company founded in the 18th century by the Dollond family of English opticians and instrument makers. This diagram is from 'An Introduction to Practical Astronomy', published by William Pearson in several volumes between 1824 and 1829.
Model release not required. Property release not required.