A rare lot of three vintage technical instruction manuals produced by the historic British scientific instrument maker, C. F. Casella & Co. Ltd. These manuals are essential documentation for collectors of optical surveying, military mapping, and aerial photography instrumentation.
Included Documents in this Lot:
- 1x Instruction Leaflet No. 3065/RO: "Folding Mirror Stereoscopes and Stereometer or Parallax Measurer" (Fitzroy Square variant cover, thicker booklet format).
- 2x Instruction Leaflets No. 3065/RO: "Folding Mirror Stereoscopes and Stereometer or Parallax Measurer" (Britannia Walk variants, clean dual-column typescript layout).
These manuals outline complex calculations, technical equations for parallax measurements, tool indexing for the Parallax Bar, calibration steps, and setup instructions for interpreting aerial and geographical landscape depth.
Condition Report (Please Read Before Buying):
This set is in weathered Acceptable vintage condition, showing standard wear from professional workshop or laboratory storage:
- Internal Pages: Excellent reading condition. The inner typewriter-style text blocks, mathematical equations, and instruction grids are exceptionally bright, crisp, and clean. There are no heavy ink scribbles, missing text blocks, or liquid damage bleeding across the pages.
- Covers: The buff-coloured paper card wrappers show distinct age-toning, surface thumb grubbiness, light creasing, and minor storage rust marking on the staples.
- Edges: Standard minor edge scuffing and rounding at the corners.