46 The Ottawa Naturalist. [June-July 



shelf these screws are easily changed and the holes may be 

 puttied up and touched with color, although if left they will 

 no more disfigure the case than the ordinary ratchets used for 

 holding shelves at various heights. The case may be stained 

 or painted with a dull finish, certainly not a very glossy var- 

 nish, perhaps preferably with a thin wash, to give it a somewhat 

 neutral color in harmony with that of the walls of the building 

 in which it is to stand. 



The back of the case, it seems, should certainly be put on in 

 the same way as the front, so that if it is ever desirable to turn 

 the case at right angles and have glass upon both front and back, 

 the back may be removed and a glass frame similar to the one in 

 front may be put on as easily as one would open and shut the 

 case to put in or take out a specimen. If the back is to be solid 

 woodwork, which is perhaps desirable where heavy things are 

 to be hung from it, care should be taken that it is built so that 

 the expansion and contraction due to changes in the weather 

 or the heating of the building may not strain the rest of the case, 

 and the boards should run up and down or crosswise rather than 

 either diagonally or possibly even in panels, so that they may 

 not be optically disagreeable in connection with the exhibit. 

 Perhaps as good a way as any woidd be to let the back of the 

 case be a frame with compo board instead of glass, as the compo 

 board could be replaced at any time glass was desired, and 

 meanwhile would serve very well as a background to exhibits 

 or upon which to hang exhibits that were not too heavy. A 

 diaphragm set back against the rear frame would serve for 

 heavy objects and be desirably smooth or could be covered with 

 burlap, paint, paper, or what not, as desired. 



When the case has glass front and back, that is, when the 

 exhibit is to be viewed from two sides, or when it is not desirable 

 to use the full depth of the case for the exhibit on hand, a dia- 

 phragm about 14 of an inch shorter and narrower than the inside 

 of the case may be inserted at any distance from the front of 

 the case, and held in place either with round headed screws 

 through the sides of the case or with small angle irons or ^-inch 

 cove, in front and behind the diaphragm at the corners, or 

 oftener according to taste and the amount of strength desired. 

 This method of fastening the diaphragm allows it to be adjusted 

 or removed in a very few minutes with practically no waste and 

 no unsightly scars which could not be retouched with putty 

 and colored, or which if not retotiched would be no more un- 

 sightly than the complicated and expensive diaphragm holders 

 usually used. 



The cases should be made in uniform sizes or multiple sizes 

 like sectional book cases, so that they may be moved about and 



