Having said so much about making up the size, let me add a few words as to other preparations that are sometimes necessary.  In a good lantern transparency, it is, of all things, indispensable that the high lights be represented by pure glass, absolutely clean in the sense of its being free from any fog or deposit, to even the slightest degree; it is also necessary that it be free from everything of heaviness of smudginess in the details.  To obtain these results, I generally have recourse to the strengthening of the high lights of my negatives, and this I do with a camel’s hair brush and India ink, working on the glass side.

I nearly always block out my skies, and so strengthen the other parts of my negatives, that I can rely on a full exposure without fear of heaviness or smudginess.  This blocking out is easily done.

Haying said so much about the preparation of the negative, let me now describe the apparatus I use.  I have here an ordinary flat board, and here my usual camera; it is the one I use both for outside and inside work.  It is a whole-plate one, very strongly made, and has a draw of twenty-three inches when fully extended; but this is not an unusual feature, as nearly all modern cameras have their draw made as long as this one.  The lens I use is a Ross rapid symmetrical on five inches focus, and here I have a broken-down printing frame with the springs taken off, and here a sheet of ground glass.  This is all that is required.  I mention this because I find it generally believed that a special camera is required for this work, such as to exclude all light between the negative and the lens; in my practice I have found this unnecessary.  There is nothing to hinder the use of ordinary cameras, provided the draw is long enough, and the lens a short focus one.

Now let me describe how to go to work.  I take the negative and place it in the printing-frame, holding it in its place with a couple of tacks, film-side next the lens, just as in printing; then stand the printing frame on its edge on the flat board, and place the ground glass in front of it—­when I say in front of it, I mean not between the negative and lens, but between the light and the negative.  The ground glass can conveniently be placed in another printing frame, and both placed up against each other.  I then bring my camera into play, and so adjust the draw and distance from the negative, till I get the picture within the disk on my ground glass.  I find the best way is to gum a transparency mask on the inside of the ground glass; this permits of the picture being more easily brought within the required register.  This done, focus sharply, cap the lens, and then proceed to make the exposure.

Now, what shall I say regarding exposure?  Just let us bear in mind again that it is merely a printing process we are following up, as you will all know that in printing no two negatives are alike in the time they require.  So in this case no two negatives are the same in their required exposure.  Still, with the plates I am going to use, so wide is their range for exposure that but few failures will be made on this score, provided we are on the safe side, and expose fully.