1851 Great Exhibition: Official Catalogue: Class X.: Varley and Son
257. VARLEY and SON, 1 Charles Street, Clarendon Square — Inventors and Makers.
Graphic telescopes, by which general views or images of objects, either far or near, may be accurately traced, of any size.
Reversing camera, by which pictures or objects may be traced the reverse way.
Microscope, in which the moveable stage is kept parallel to one position whilst freely moved about in any direction.
Reflecting telescopes.
Model of the apparatus for mounting together and changing three small speculums of large Gregorian telescopes, so as not to lose sight of the object; thus the power may be doubled, or quadrupled, or reduced without loss of time.
Air-pump, with crank motion and double-acting single barrel.
New double-acting exhausting air-pump, with increased power.
Portable electrical apparatus on moving the inner tubes to and fro, the outer tube becomes charged in the same manner as the Leyden phial.