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picture required. This mat is sunk into the bed of the 
frame until it is quite level with it. A negative is then 
put in, and by moving the mat up pr down in its recessed 
bed, you can get more sky or foreground at will, and 
the movement right and left gives you any other por- 
tion of the picture you may desire. Having settled that 
point, I then place on the negative a straight strip of soft 
cardboard, wide enough to reach, within about an eighth of 
an inch, the bottom of the opening in the mat ; and then 
place on the prepared plate, which is kept in a horizontal 
position by resting on the strip of cardboard ; and it also 
enables you to get the two sides of the picture exactly on a 
level with each other after reversing, to close the frame. A 
loose back, with a brass spring on, is put in, and a small 
lever bar brought down over the spring and held in its 
position by a small catch. It is necessary to have several 
strips of cardboard, varying in width, and it will be obvious 
to any one that they must not exceed in thickness the glass 
of the prepared plates, otherwise the pressure of the back 
is kept off the glass and the plates are not in close contact. 
By use of this frame I can easily take out for the 
lantern portions of pictures taken the full size of the plate, 
say 7 Jin. by 4 Jin., whether the subjects be horizontal or 
upright. 
Mr. Dancer then exhibited, by means of the oxyhydrogen 
lantern, a very beautiful series of views, by Mr. Buxton, 
representing scenes in Scotland, Egypt, India, &c.; and also 
views in Derbyshire, Cheshire, and other places, by Mr. 
Coote and Mr. Brothers. 
