1851 Great Exhibition: Official Catalogue: Class X.: T. and R. Willats
265. WILLATS, T. and R., 28 Ironmonger Lane, Cheapside - Inventors and Manufacturers.
Improved portable photographic camera and stand, for obtaining pictures by any known photographic process, on metal plates, paper, glass, etc.
The advantages of this form of camera are, the facility with which it can be packed into a small compass; the adjustments for placing the paper or plates at the proper focus, without exposing them to the daylight; and the comparatively small weight of the apparatus: thus rendering the practice of photography easy to a traveller.
Improved registering thread calculator, or linen prover, to ascertain the number of threads in a given space, of silk, linen, or cotton fabric, and to register this number on paper.
It is of importance in purchasing any woven fabric, to ascertain the number of threads, warp, and woof contained within a square inch, as the knowledge of these enables the purchaser to judge of its strength and durability. This instrument is devised to render the operation easy to the merchant.