For developing our plates a " dark-room " is essential, and when we say a " dark-room " we mean a real " black room," as they have it in French, and not a room in which things are barely visible after having been in it for some minutes. The dark-room should be one in which not a trace of white light can enter. Of course, many amateurs have to content themselves with coal or wine cellars, or even bedrooms at night, but in any case care should be taken to shut out every trace of light that might fog our plates.
If a room has to be made into a temporary dark-room by means of blinds or screens, it is very desirable that these blinds or screens should be opaque, and that artificial light only be used for development. Perhaps the best way to do this is to have two blinds, one a red one which will make the room safe for bromide work and another a black or green blind which, coming down over the red one, entirely cuts out any trace of light and makes the room absolutely dark.
The " De Luxe " method of lighting, where a room is at the disposal of the photographer and where he has electricity, is to have all the light used for illumination reflected from the ceiling. This is effected by having tubular electric lamps arranged in a moulding like a picture rail, and these lamps are covered with orange glass. Most workers, however, require a lamp, and the largest possible is the best, providing it is safely screened. If an electric lamp is used the lantern body should have grooves at the front which will take any combination of glass or fabric, and should also have screens at the sides to light up the bench or shelves. A similar lamp may be used for paraffin, and in this case the oil reservoir should be large and fitted with a good burner. Most of the commercial lamps are eminently unsatisfactory, due to the constant cutting of prices.
THE ILLUMINATION OF THE DARK-ROOM.
* The Sinclair Dark-Room Blind is made on these lines.
If from considerations of pocket a cheap lamp must be purchased, it is advisable to throw away the piece of ruby glass and substitute for it a screen made of two thicknesses of ruby fabric, either between two glasses or with the edges bound with tin. The Ilford lamp screens are also strongly recommended ; and a Wratten screen is essential for Panchromatic plates.
In fitting up a dark-room have a good large sink, lead-lined, with shelves on both sides and a narrow shelf at back, all of which should, if possible, be lead-covered. The water supply may be in the form of a swing tap with reversible end, or simply a tap to which a Berkefeld filter or a simple " anti-splash " is attached. Warm water is a great convenience, and if it cannot be obtained in the darkroom an instantaneous water heater of extremely small size may be hung on the wall at the back of the sink and attached to the water supply. This will give a supply of hot water at the rate of a quart a minute, but it can only be used where there is a gas supply. Below the sink and its adjacent shelves should be arranged a drawer for developing clips, brushes and other sundries, and below this again a shelf to hold hypo tank and also racks for developing dishes.
Wires may be stretched across the room and above the developing sink, and these are useful for suspending prints by means of clips for drying purposes.
Developing dishes should be of porcelain, or preferably, of granitine, a sort of white porcelain which will stand quite considerable heat. It is easy to see that such dishes are clean.
In looking through a catalogue many things will be found desirable for dark-room equipment, and the matter of racks, washers, measures, etc., may be left to the individual requirements of the photographer.