One other thing required is a set of clamps for binding the tripod legs together. These are, I believe, made by George Mason, of Glasgow, but any dealer will procure them for you.

The use of the right kind of plate constitutes a very important factor in the production of a satisfactory negative, particularly in this branch.

Owing to the greater difficulty experienced in developing extra rapid plates, one generally sees the slower variety recommended. No hard and fast rule can however be laid down. To gain the best result, the plate must be suited to the subject.

For instance, in a very dark interior in which heavy black shadows predominate, many of them appearing much darker than they really are owing to their close proximity to a strong light, the quicker the plate used the better. This tends to break down the harsh contrasts, and at the same time the shadow detail is considerably better rendered.

On the other hand, working in a light interior or one which is flat owing possibly to the large amount of light present, a slower plate can be used with advantage, and, providing the exposure is sufficient the result will be all that is wished for.

Exteriors, particularly those in sunshine, should be photographed on a fairly quick plate. Slow plates, although good, do not yield nearly such good negatives, and unless very fully exposed give excessive hardness.

Taking this class of work all round, the quick plate is the more useful of the two and is undoubtedly the best for interior work, particularly such interiors as one meets in our English cathedrals.

For all subjects possessing strong high-lights, such as windows, stained or otherwise, rapid plates combined with a suitable backing composition yield the best results, and I would impress upon the reader the fact that no plate should ever be placed in a dark slide without being covered at the back with a suitable composition for the prevention of halation.