PHOTO-MICROGRAPHY. 75 
ordinary 7+ ins. x 44 ins. camera, with which I was enabled to take 
,, several verygood pictures. Finally 
I have settled down to the one as 
shown in the illustration (Fig. 7), 
which was made for me by Mr. 
Furnivel, of 5, Kay-street, Ard- 
wick Green, Manchester, who 
treats microscopic cabinet making 
as a speciality. 
And now, perhaps, you can 
see the usefulness of a practical 
treatise on the subject; had I 
been able to see such a camera 
as this one at the outset, I should 
be some pounds richer, and in- 
stead of plodding along for a 
whole year, constantly making 
alterations, I might have spent 
the time much more profitably. 
Perhaps you will be inclined to 
say that up to this point I have 
advanced nothing new, many 
having written on this subject; 
but what I wish to say most 
distinctly is, that it was the very 
existence of this literature which 
caused me to spend my money 
with such an unprofitable result. 
The dark slide of the camera 
shown in Fig. 7 is made to take a 
large square plate, with carriers 
for any less size. The most handy 
dimensions, especially for the be- 
ginner, is the quarter-plate as it is 
a termed, and measures 4} x 3} 
NESTE inches ; it is only for special pur- 
poses that it need be larger. Of course the length of the base- 
board and of the camera body must depend upon the degree of 
amplification required, and the diameters to which an object is 
enlarged in my own camera when the sensitive plate is at a distance 
of 36 inches from the object may serve as a guide in this direction. 
This is when using the microscope without the eye-piece as is 
the general practice ; but it is sometimes necessary to use this, and 
therefore the list of diameters so yielded, is given, and compared 
with the ordinary amplification at ten inches when used as a 
microscope merely. 
