10 NATURE AND THE CAMERA 



cept in England), and it is difficult to find one that 

 is satisfactory. Most of them are good enough for a 

 very short time, but they invariably leak if they are 

 used for any length of time. If made of any material 

 containing rubber, they are useless, as the rubber soon 

 perishes. Of the materials which I have tried, pan- 

 tasote seems the best. It is absolutely light-tight, 

 and wears well. A simple form that answers for a 

 changing-bag is a square box-shaped bag well rein- 

 forced and bound on the edges. At each corner 

 there is a loop to which cords are attached that will 

 hold the bag in position ; two sleeve-like openings 

 (with rubber bands to hold them closely about one's 

 arm) on one side admit the arms, and should be made 

 large enough to let the plate-holders enter. For a 

 changing-bag this is all that is needed. Of course 

 we cannot see what we are doing, but that is seldom 

 necessary when once we know our plate-holders. 



. A really portable field-developing tent is one of 

 the much-needed things. At present there is nothing 

 on the market in this country, though I understand 

 one is about to be made. There are two patterns 

 of these tents or boxes: one in which you put your 

 arms inside, and with your head outside you look 

 through a yellow glass window, another yellow or 

 red window being on the opposite side. This has 

 the advantage of coolness, but it is difficult to see 

 very clearly. The other is a cloth and wood box or 



