184 



Proceedings of TmJhina Academy of Science. 



constructed as to fit in any standard olociric li,i,dit socket. Any convenient 

 method of supplying lieut b;^- electric current may be used. It is important, 

 however, that only a small amount of heat be supplied. It is only necessary 

 that a draft of warm air passes through the corrugated boards of tlie press. 

 Three one inch auger holes two inches from the bottom are provided on 

 each side of the box to allow for intalce of air. 



The sides of tlie press are made of one inch boards 12% by 18 inches. 

 It is best to fasten a piece one and one-half inches wide crosswise at 

 either end to prevent warping. This should be tongued and grooved 

 and glued. Canvas straps with friction buckles are permanently fastened 

 to the boards at either end as shown in the illustration. These should 

 be of such length as to allow for the maximum expansion which the width 

 of the box permits with sutficient additional length to conveniently allow 

 for drawing the press tight. Double faced corrugated straw boards cut so 



Fig. 1.— The Plant Press in Use. 



Double faced corrugated card boards, cut so that the corrugations extend 

 the short way, are used between the driers. 



Heat is supplied by two or three carbon filament electric light bulbs, or 

 by special heating units constructed to fit an ordinary electric light socket. 



Any thickness of press, within the limits of the width of the box, can 

 be used. Boards one and one-half or three inches wide are provided to fill 

 in the space at the sides of the press on the rack when only a small amount 

 of material is to be dried. 



Ventilation is provided by six one inch auger holes placed three on each 

 side of the box, two inches from the bottom. Photo by M. W. Gardner. 



