Ss ae 
very nearly all the actinic rays, leaving me at the same time, 
ample light to see what I am doing. But I wouid advise 
that all yellow glass which it is intended to use for this pur- 
pose, should be tested before setting, as the eye alone is not a 
reliable test in such cases. There is some light and beauti- 
fully colored yellow glass in the market, which is of no use in 
photography, but that which is darker and of an orange tint I 
have found to be thoroughly reliable. A small fragment may 
be readily tested by exposing a piece of paper covered with 
Silver Chloride under it to the direct rays of the sun for a 
few minutes. . 
Perhaps I can best make plain the manner in which J manipu- 
late by describing, first, the room in which I have been in the 
habit of working and the arrangement of the materials 
and apparatus therein. I shall begin with the window. It 
is small, but large enough to illuminate the whole room, 
which is itself small, as no very great space is required in 
this kind of work. At thesame time the manipulator should 
not be cramped. A closet of the size that when one is stand- 
ing in the middle of it, by one step in any ‘direction all of 
the walls may be reached, will be found to be ample in 
dimensions; that which I used for a long time, and which I 
am describing, was somewhat larger, but in it I had space to 
store much of my photographic apparatus and material, 
which I now think would have been best left out. On alow 
table or bench, about two feet six inches high, placed imme- 
diately beneath the window, are arranged the vessels, solu- 
tions and apparatus I use in such an order that I could 
always lay my hands on them even in the dark. Thus, on 
the extreme left against the wall, are shelves with stock bot- 
tles of solutions, while on the left end of the table stands a 
large porcelain bath and dipper encased in a wooden box, 
with cover made so as to shut when necessary to exclude 
dust. Porcelain baths I find the cleanest and most reliable, 
much more so than glass with joints of any kind. Next in 
order towards the right from the silver bath, comes the 
pan containing the solution of Sodium Hyposulphite used 
for fixing. This pan is made of the so-called photographic 
