156 W. M. GKAHAM — THE PHOTOGRAPHY OF DIPTERA. 



As soon as the insect is sufficiently dry it is ready to be photographed, and for 

 this purpose must be transferred from the disc of cardboard to the glass support 

 already described. To do this, take the easel and introduce the glass support into 

 the grooves so that the hole in the glass plate filled with cork is in the middle of 

 the square opening in the easel. Then take a pin of the same size as that in the 

 insect you are about to transfer from the cardboard disc and push it gently 

 through the centre of the piece of cork cemented in the glass support. This will 

 render easy the subsequent introduction of the sharpened end of the pin bearing 

 the insect. Now remove the paper supports, take the disc bearing the insect 

 between the fingers and thumb and gently push up the pin from beneath until it 

 can be grasped by a curved forceps introduced between the insect and the disc. 

 Holding the pin thus grasped in the forceps, draw off the disc, and introduce the 

 sharpened end of the pin into the pinhole already made in the piece of cork in the 

 glass support. Then from the back draw the pin through, until the legs of the 

 insect are in contact with the glass plate, the head of the insect being so placed 

 that it will be directed downwards when the easel is clamped in position on the 

 base-board. 



Now clamp the easel in position and arrange the millimetre scale above the 

 insect, in the same vertical plane, and near enough to the insect to be included in 

 the picture on the ground-glass. In the absence of the slide for the purpose, 

 this can be effected by pushing a long pin through the wooden rod attached to 

 the scale and pinning it to the wooden easel. 



Illumination. 



The lighting is effected in the following manner. The whole apparatus, 

 arranged according to the above directions, is placed upon a table either in front 

 of, and parallel with, a well lighted window, or in an open verandah where it will 

 be sheltered frorii the wind. On the table behind the easel is placed a large 

 reflector formed of a drawing-board with a sheet of white Bristol board pinned 

 upon it (fig. 2). This reflector is to be inclined at such an angle as will secure 

 imiform lighting of the whole of the opening in the easel. The amount of light 

 from the reflector can be regulated by varying the distance of the reflector from 

 the easel. 



On the base-board, immediately in front of the easel, is placed a small square 

 glass mirror (5" by 5") inclined at such an angle as will light the insect on the 

 easel uniformly from below. Care should be taken that the reflection of the 

 edge of this mirror is not included in the picture on the ground-glass, and that 

 sharply defined clouds are not reflected. 



On the table on the left-hand side of the base-board, and slightly in front of 

 the easel, is placed a shaving mirror upon its stand. The mirror should be raised 

 slightly above the head of the insect and inclined at such an angle as will secure 

 the uniform lighting of the left side of the insect by light reflected from the 

 mirror. 



The object of the plate of glass, here used as a support, is to avoid the heavy 

 shadows which would be cast by the body, legs and wings, of the insect upon an 

 opaque support. The object of the white reflector behind the easel is to furnish 



