Rolling Prints Sculpture, Photographic
using the same in a continuous band for the purpose of expos-ing on many subjects without changing, and for this purpose the roller slide was devised quite in the early days of photography. (See Film Photography.)
Boiling Prints. Consists of passing prints between two rollers, or between a roller and a bed of steel. It improves the appearance, and causes the print to lie flat. (See Burnishing.)
Rontgen Rays and Method. See Radiography.
Ruby Light. See Dark-Room.
Salicylic Acid (Ger., Salicylsaure; Fr., Acide Salicylique)^ HC7H503. Occurs naturally, but is prepared commercially by heating carbolic acid with caustic soda and passing carbonic acid into the mixture. Solubility: I in 700 of cold water, 1 in 9 of boiling water, 1 in 4 of alcohol; 20 grs. with 20 grs. of borax or acetate of potash will dissolve in 1 oz. of water. It is but rarely used in photography; as a preservative it is added to some mountants.
Scales. See Weighing and Measuring.
Screen, Coloured. See Isochromatic Photography and Photography in Natural Colours.
Screen, Lantern. See Aerial Screen ; also Magic-Lantern.
Screen, Ruled. See Fish Glue Process.
Sculpture, Photographic. A method was formerly in use by which a number of silhouettes taken simultaneously served as a mechanical guide in the first modelling of the clay. (See a suggestion in article Polypose.) Bas-reliefs may be made by the following process, given in The Amateur Photographer : M Grind a lantern-sized plate, and having set it tolerably level on the rim of a wine-glass, flood it with the following mixture: -
Gelatine ... ... ... ... ... 60 gr.
Water ............... 1 oz.