Caliber compasses. Engraving of a diagram of a pair of caliber compasses. These were used to assess the size and thus the weight of projectiles such as cannon balls and to measure the interior diameter of gun barrels. This plate was published in George Gregory's A Dictionary of the Arts and Sciences,printed at London in 1807 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Middle Temple Library |
Taille de l’image : | 4257 px × 4068 px |
Model Release : | Non requis |
Restrictions : | - |