146 
NOTES ON PRINTING ON 
A Hinck's kerosine wall-lamp, with an one-incli wick, is 
as good a light to print by as any. Day light is too quick, 
and in consequence unmanageable. Remove the globe and 
reflector, if it has one, and keep the chimney only in place. 
The oil should be of the best, and during exposure it should 
burn at its brightest. Place the lamp on a table, and, at a 
distance of two measured feet, lay down a couple of books, 
80 as to make a platform about 2 inches high for the printing 
frame to stand on. Spread a sheet of white paper between it 
and the lamp to reflect the light, and, when all is ready, turn 
the lamp down as low as possible. It will still give quite 
sufiicient light whereby to load the printing frame, and be 
quite safe, especially if ones back is turned to it, or a screen 
intervened, whilst making the transfer of the sensitive sheets. 
A negative, such as has been above described, having 
been put into the frame, and backed by a sheet of bromide 
paper is placed on the platform of books, and the light is 
turned up to its brightest. Now, looking at the negative by 
this light and in this position, the greater part of the picture 
will, to some extent, be disoernible, owing to the negative 
being so thin ; if so, try 30 seconds' exposure, or, if part only is 
visible, try 45, or even 60 seconds as the case may be. Time 
up, tiirn down the light, and remove the paper. At first 
one print only should be taken, until it has been seen by 
development whether or not the exposure has been coiTect. 
A book ruled for the pm-pose should be kept, showing the 
exposure given to each negative, not only for futm-e reference, 
but also for comparing a negative about to be printed, with 
those of which the time of exposure has already been ascer- 
tained. After a short time it will be easy to tell at a glance 
what the necessary exposure should be. The distance of 2 feet 
is given as being a good medium one, and for no other special 
reason. It must, however, be borne in mind that the time of 
exposure increases or decreases according to the relative 
square of the distance. For instance, a dense negative that 
