192 THE FORMATION 



benefit. When the picture is worth the trouble, a tent may be erected to 

 afford a very efficient protection. This is too prodigal of time and energy, 

 however, to be practicable under the usual -conditions. Flashlight exposures 

 on still nights are sometimes feasible, but the disadvantages connected with 

 them are too great to bring them into general use. The best procedure is 

 to bide one's time, and to take quadrats, transects, and other detail areas, 

 as well as many plant groups, at a time that promises to be most favorable. 

 Single plants can often be moved in the field so that they are protected from 

 the wind, or so that they are more strongly lighted. Slender, or feathery 

 plants are usually very difiicult to handle out of doors. The best plan is to 

 photograph them in a room that is well and evenly lighted, or, best of all, 

 in a stable, roomy tent. 



239. The sequence of details. No photographer ever escapes blunders 

 entirely. At the outset of his work, the ecologist must fully realize this, 

 and accordingly plan a method of operating the camera which will reduce 

 the chance of mistake to a minimum. The usual blunders which every 

 one makes sooner or later, such as making two exposures on one 

 plate, drawing the slide before closing the shutter, allowing the light to 

 strike the plate through the slit in the holder, etc., can be all but absolutely 

 avoided by a fixed order of doing things. This order will naturally not be 

 the same for different persons ; it is necessary merely that each have his own 

 invariable sequence. The following one will serve as an illustration. As a 

 preliminary, the plate-holders are filled, after having been carefully dusted, 

 and the slides are uniformly replaced with the black edge inward. It is a 

 wise precaution to again see that all the slides are in this position before 

 leaving the dark room. This will ensure that .a black edge outward always 

 means that the plate has been exposed. The tripod is first set up and placed 

 in what seems about the proper position. The camera is next attached to it, 

 and the front and back opened. The bellows is pulled out, a short distance 

 for views, and a longer one for detail pictures, and fastened. It is necessary 

 to move the diaphragm index to the largest aperture and to open the shutter 

 at "time." The next steps are to orient the view or object, and to bring it 

 into sharp focus upon the ground glass. The first is accomplished by moving 

 the entire instrument, changing the position of the tripod legs, swinging the 

 camera upon the tripod, or by raising or lowering the lens front. It is often 

 desirable also to change the position of the object on the plate by use of the 

 reversible back. In views with much distance, the foreground is brought 

 into sharp focus. In close views, especially of quadrats, the swing is used 

 to increase the distance for the foreground, and the focus is made upon the 

 center. After focusing, the shutter is closed, the indicator set at the time 



