t is well to have this ground-glass
fixed in place so that it can be readily removed if desired.

[Illustration: Fig. 6]

The necessity for having the box at least two inches larger each way than
the largest negative from which enlargements are to be made is shown in
Fig. 6. Here AB represents the negative in place, CA, DB and EG represent
rays of light entering the box. It will be seen that the rays CA and DB
strike the ground-glass at an angle, but nevertheless at an angle which
results in their passing through it in a considerable degree. They strike
the negative AB, but if the negative were the full size of the box, to wit
FG, it will be seen that while the section AB would be fully lighted, the
sections AF and BG would receive no oblique rays at all, and hence the
negative would not be even approximately uniformly lighted. This point is
too often overlooked in the construction of apparatus of this character,
but is necessary in all cases of daylight enlarging and especially when
direct sunlight is used. Now with the negative box in place, some
arrangement must be made for holding the lens, which can be the lens used
for making the negative. This for enlargements of a fixed size from
negatives of a given size can be accomplished by simply extending the
section BGGC Fig. 3, to a proper distance and placing the lens in the end
of it; but this permits too little opportunity for adjustments and is not
advisable. A double box, one sliding within the other, would be better,
but still not quite satisfactory. It is far better to adapt one's camera
to the apparatus, and this can always be done; it being very simple with a
reversible back camera, which can be backed right up to the opening, and
more difficult but always possible with others. Fig. 7 shows the entire
apparatus in place, and the manner in which it is used. AB is the window
board, C is the negative box, D is the camera adjusted to the latter, E is
the enlarging screen on an easel to hold the bromide paper, and F is the
reflector. The screen on the easel can be made either to rest on the floor
or on a table. It can be made to run on a track or otherwise, and it can
also be made so as to admit of either vertical or lateral adjustment or
both, or it can be nothing more than an ordinary box set on a table. But
however constructed it must be considerably larger than the largest sheet
of bromide paper which is to be used, thus allowing for nearly all
necessary adjustme