Where it is possible to bring the water from the main supply of the house to a tap immediately over the developing sink, it will be found very convenient. This, however, is not often possible, and the next best thing is to have a covered tank placed in such a position that it may be readily filled and connected by flexible tubing with the developing-sink tap. A supply of water in a can is less convenient, but will be found useful where other means are not available, and there is not a very great deal of work to be done.
Water of ordinary quality will do for general photographic purposes, as washing plates, rinsing out dishes, measures, etc. Sand in water from gravelly beds sometimes causes trouble in washing, as it gets embedded in the gelatine and projects after the film has contracted in drying. To avoid this a small piece of flannel should be tied over the tap and the water allowed to strain through it. When, however, developing and toning solutions have to be made up, as good quality water as possible should always be used, or impurities may cause unlooked-for troubles. Distilled water must always be used for making up gold chloride solution. Soft or rain water - which has been boiled and cooled - will be found satisfactory for the other solutions; failing a supply of this, ordinary drinking water will suffice. If there be any hardness - which is always indicated by its action with soap, producing a flocculent scum on the surface - it may be partially removed by boiling, to drive off carbonic acid gas; after the water has stood sufficiently long to become cold, lime will be precipitated, from this the clear water should be carefully poured off. It would be perfectly useless to attempt to soften water for photographic purposes by chemical means.
A run or two of shelving will be found useful in the dark-room for purposes of storage, etc. It must always be carefully borne in mind that all sensitive materials must be stored low down, or they will become affected by gas or other fumes.
Where much time has to be spent in the dark-room, especially if artificial light - except electric - is being used, some means of ventilation must be arranged. Circumstances will probably suggest the best means of obtaining it. At all times, after work is completed, the window and door should be thrown open to allow a free circulation of fresh air. Any stray light admitted through the crevices of the door must be shut out by means of a curtain draped on the outside.