Sulphuret of Carbon

(See Carbon Disulphide.)

Sulphuric Acid

(See Acid Sulphuric.)

Sulphurous Acid

(See Acid Sulphurous.)

Sulphur Toning

A method of producing sepia or warm tones on bromide prints. Affected by prolonged immersion in a hypo alum bath.

Supersaturated

Saturated to excess

Flexible or Temporary Support

A sheet of waxed paper used in the carbon process and employed for a temporary support on which the carbon is placed for development. After development the print is transferred to a final support.

Permanent Support

The final support used in the double-transfer carbon process.

Temporary Support

(See Temporary Support.)

Swing-Back

(See Back, Swing.)

Swing-Bed

(See Bed, Swing.)

Double Swing

1,87; III, 14.

A camera is said to have a double swing when the back can be moved both in a horizontal and in a perpendicular position.

Front Swing

(See Bed, Swing.)

Symmetrical Lens

(See Lens, Symmetrical.)

Syphon

A curved tube, one end of which is longed than the other. Used for transferring liquids from a higher level to a lower one. After starting the solution will flow through the tube to the lower vessel. The syphon is useful for removing a liquid without disturbing the precipitate at the bottom of the dish. A rubber or glass tube may be used for this purpose.

Tank Development

A method for developing plates in an upright position. Essentially the process consists of a zinc tank having grooves in the sides, into which the exposed plates may be inserted. A light-tight cover is fitted over the top of the tank. A sufficient quantity of developer is placed in the tank to cover the plates. The average tank will hold from six to twelve plates, thus permitting of that number being developed at one time.

Tannic Acid

(See Acid Tannic.)

Tannin

(See Acid Tannic.)

Telemeter

An instrument for ascertaining the distance at which any object is situated.

Telephotographic Lens. (See Lens, Telephoto.)

Telephotography

The photographing of distant objects by means of the tele-photographic lens.

Temperature

The degree or intensity of the sensible heat of a body. The temperature of the work room, as well as of the various solutions, is of vital importance to every photographic worker. Low temperature tends to retard the formation or development of the latent image, while high temperature accelerates it.

Temporary Support

The support used in the double-transfer carbon process, on. which the image is developed. The pigment is afterwards transferred from the temporary support to the final support, which operation gives a reversed picture.

Tessar Lens

(See Lens, Tessar.)