7 o 



NATURALISTS' ASSISTANT. 



strip of cotton wool has been tacked to the door, at oth- 

 ers the door and frame are fitted with tongue and groove. 

 This is possibly the best method and is employed in the Yale 

 cases. A cheap means has been adopted at the Peabody 

 Academy of Science with good results. A thin strip of rub- 

 ber packing is folded and fastened by means of a strip of 

 wood to the case and against this fold the door closes sending 



the joint all but air- 

 tight. The construc- 

 tion is readily seen from 

 figure 23. The floor of 

 a vertical case should 

 be some few inches 

 above -the floor of the 

 exhibition room, and the space 

 thus left may be occupied by 

 drawers for the storage of speci- 

 mens. The shelves in an upright 

 case should be adjustable to any 

 desired height. A perfect method 

 of accomplishing this yet remains to be invented. Sometimes 

 sticks fitting into ratchets on which the shelves are supported 

 are employed, others support the shelves on "screw eyes" 

 screwed into the frame of the case. But doubtless the best 

 apparatus is the adjustable brackets. Two patterns of these 

 are made, one by Mr. Jenks and one by Mr. Gavitt, each 

 having its merits and objections. Possibly the former is 

 preferable. Each of these employs an iron bracket (hori- 

 ; cntal or inclined as may be desired) which hooks into an 



FIG. 23. 



