INTRODUCTION. 6 



the use of which the strength of the arm is of no essential value, and the 

 propelling power originates in chemical combustion. 



Accessory to these are groups containing those articles used in the 

 manufacture, testing, loading, and transportation of these missiles, and 

 the machines which drive them through the air. 



In a fourth division is the apparatus of angling, which is separated 

 from hooked implements with which the form of the articles would natu- 

 rally place them, since they are not implements of grasping, but partake 

 of the nature of traps, being in part automatic. 



The group of nets is a heterogeneous one, as has been stated above, 

 consisting of two divisions, the first that of eutangling-nets, belong- 

 ing properly with traps, while encircling-nets are iu idea instruments 

 for grasping. 



In arranging traps a logical succession has been preserved as far as 

 possible. Those traps are considered the most" simple in which the 

 animal is penned by its own act, without any change in the arrange- 

 ment of the trap. The pit-falls or u tipes" are first, followed by the mazes 

 or labyrinths of greater or less complexity. Then come the traps in 

 which the entrance is closed, either by the falling of a door or by the 

 falling of a box-like trap, as a whole, so as to surround the animal. 

 Under clutching-traps are placed those which seize the animal, as in the 

 fingers, while crushing-traps are those which seize or impale it bodily. 

 Adhesive preparations, such as bird-lime, close the series. 



The accessory divisions, including hunting- animals, decoys, and dis- 

 guises, and the methods and appliances of pursuit, do not admit any 

 thorough classification, and are arranged with reference to convenience 

 of exhibition. 



Section C includes all methods of utilizing animals' products. It 

 might be more satisfactorily arranged with the following section, were 

 it not for the inconvenience of exhibiting models and tools in the same 

 cases with the manufactured products ; the arrangement of the two sec- 

 tions is nearly the same. 



In Section D are grouped all useful substances derived from the animal 

 kingdom. In order to avoid the omission of any products which are 

 or may be obtained from North American animals, this enumeration has 

 been made general, those not American being included in parentheses. 

 This enumeration is far from complete, and is intended simply as an 

 aid to future study in the same direction. 



Section E includes all articles illustrating the culture and protection 

 of useful animals. 



