REPORT OF ASISSTANT SECRETARY. 29 



(3) Of paper. This form of bottom grew out of the desire for a 

 lighter and cheaper form of tray.* in the early storage cases deep 

 drawers were used, cliiefly for reasons of economy, and small pasteboard- 

 bottomed trays, four of which covered the bottom of a unit drawer, 

 were used to contain birdskins and other small objects, these being 

 I)iled one above anotlier in several layers. This was inconvenient and 

 detrimental to the specimens, and the real desideratum i>roved to be a 

 liyht shallow drawer of moderate cost, in which specimens could be 

 stored in a single layer. It should be said that the old system of deep 

 drawers was also in part the outgrowth of the necessity for making 

 the drawers themselves dust and moth proof. This was in the days 

 before air-tight cases had been developed, and skins of birds and mam- 

 mals were kept in glass-covered boxes, similar to the unit box. The 

 development of the light paper-bottom tray was simultaneous with that 

 of the m(>th-proof case. 



In the search for a light and durable drawer of this kind many 

 experiments were made. The first stage was that of binders' board, 

 then followed tin, then light three-x)ly veneering, then wire-gauze cov- 

 ered with paper, then cotton cloth painted, then cotton cloth covered 

 with paper, and finally the bottom made of paper alone. These bot- 

 toms are made only in the Museum workshops, it never having been 

 found ])0ssible to get a contractor sufficiently careful to furnish sat- 

 isfactory drawers. The materials used and the process employed are 

 as follows: 



Materials. — (1) Brown manila paper, 150 pounds to the ream. The 

 size of each sheet (from which two bottoms are made) is 40 by 48 inches ; 

 (2) common flour paste; (3) brown shellac of commerce, dissolved in 

 alcohol. 



Tools. — The tools are a bookbinder's knife, a broad, flat paste brush, 

 a stout wooden stretcher, 27 by 33 inches, which is the size of the bot- 

 tom before it is trimmed. This stretcher is of pine, at least 1^ inches 

 in thickness, in order to resist the strain of the shrinkage of the paper 

 when drying. There should be, of course, a considerable number of 

 these stretchers (PI. 9, fig. 1). 



The process. — A sheet of jiaper is jjasted to the large wooden stretcher, 



* The size and estimated cost of the trays with paper bottoms now in use iu the 

 Museum aud of the stretchers used iu making the trays are here indicated : 



Department iu wlii<'h usert. 



Size. Estimated 

 cost. 



Inches. 

 Maiiiniala 24 by 30 



Do 1 24 b V 36 



Ornithology j 22 by 28 



Do./. 28by44i 



Cent*. 

 25 

 30 

 25 

 30 



Sizes of stretchers for making trays with paper bottoms: 27 by 33 inches, 29 l)y 

 40 inches, 27 by 33 inches, aud 31 by 46A inches. 



