REPORT OF THE DIRECTOR I913 



19 



server to stand close to the glass. By this means an economy of 

 aisle room is effected. (2) A ventilating device is introduced in the 

 base by means of which the air passing into the case when pressure 

 is equalized, after a sudden change of temperature, is filtered free 

 of dust through a series of sheets of cotton. 



Type N. Cases of type N were designed for the display of the 

 general collection of New York small mammals, birds, fishes etc. 

 The exhibition space is 16 feet long by 4 feet wide and 6 feet 



Type P 



6 inches high, raised on the recessed base i foot 6 inches from the 

 floor level. The case is divided longitudinally by a substantial dia- 

 phragm furnished with slotted strips upon which adjustable brack- 

 ets are fastened which in turn support the wooden shelves. ' Access 

 is gained through the second and fourth panels on both sides and 

 the two end panels which are hinged doors. The top panels are 

 glazed. The cases as at present installed are free standing arranged 



