56 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



Our field camera is fitted with a set of Turner-Reich lenses, sizes 

 18, 12 and 10 inch. 



Lighting. All our photographing, except field work, is done by 

 artificial light. The electric arc is doubtless the best all round 

 illumination. It is used by photo-engravers, who are professionals 

 and ought to know. We could not employ it because we have a very 

 low-frequency alternating current. We substituted, therefore, a 

 Nernst lamp of approximately 1000 candlepower, and have found it 

 adaptable and entirely satisfactory. For work with the large camera 

 this light is carried on a stand, four feet high, the top of which is hinged 

 and can be fastened at any angle by means of a casement window 

 adjuster. In front of the lamp is an ordinary three-inch reading glass, 

 which picks up the rays and delivers them on the object in sufiicient 

 concentration. By moving the lamp toward the reading glass or away 

 from it, the beam of light may be enlarged or diminished in diameter. 



Nernst lamps of this type are provided with four glowers placed 

 close together, which are automatically warmed to the point of con- 

 ductivity by a heater behind them. We found that when the lamp 

 was tipped forward, this heater soon burned out. Therefore we 

 removed it entirely, and use a small alcohol lamp to warm up the 

 glowers, an operation of half a minute. After the lamp is set going 

 a tin cover is placed over it to shield the operator's eyes. A consider- 

 able advantage of the use of this lamp as described, with the simple 

 reading glass to pick up and concentrate the rays, lies in the avoidance 

 of excessive heat on the object being photographed. Some heat is 

 carried through, but not enough to be of consequence. The stand 

 was made by the station carpenter. 



Both plain and concave mirrors are used near the object to offset 

 shadows, and to bring strong beams of light to bear, so as to bring 

 out essential parts, as for example to illuminate and make clear the 

 sculpturing on the wings of a beetle. The manipulation of these 

 mirrors is an important feature in obtaining a successful negative. 

 The usual proceeding is to depend on the direct rays coming from the 

 reading glass condenser for general illumination of the object and its 

 background, and on one or two concave mirrors to soften undesirable 

 shadows and accentuate high lights. Considerable experimenting 

 in the placing of these mirrors is often necessary and always desirable. 

 Surprising improvements are effected by slight changes in the direction 

 from which light rays are throTVTi, or by varying the comparative 

 intensity of two sources of light. Again, some objects will show 

 undesirable reflections with one lighting, which may be eliminated 

 with another. The larger concave mirrors are obtainable at drug 

 or department stores, where they are sold as shaving mirrors. One 



