CATALOGUE OF THE MECHANICAL. ENGINEERING COLLECTION. 101 



of steel were designed, which, combined with other products of the 

 metal worker's art, have led to the construction of the highest type 

 of wheel. To this mechanism was later added a tire of india rubber, 

 the combination resulting in the construction of the bicycle, which 

 embodies the results of the labors of the most skilled mechanics and 

 which during the decade 1890-1899 was introduced into CA^ery civilized 

 country of the globe. 



Finally the continued improvement in roads and in the internal- 

 combustion engine and the introduction of the pneumatic tire have 

 resulted in the construction and rapid development of the automobile, 

 which to-day represents the highest form of wheeled vehicle whose 

 economic value can best be expressed in the fact that for every eleven 

 persons in the United States there is one automobile in use. 



Model of Indian Elephant with Howdah. (Scale 1 : 6.) Made in the 



Museum, 



The small-eared Asiatic elephant has been domesticated for cen- 

 turies in India, Burmah, and Siam. African elephants, distin- 

 guished by their large ears, were used for transportation in ancient 

 times, but since the days of Hannibal all attempts to domesticate 

 them have failed. The model shows the method of transporting men 

 and merchandise in war or for commerce in Southern Asia. 



Cat. No. 181,275 U.S.N.M. 



Model of Llama with Panniers. (Scale 1 : 6.) Made in the Museum. 



The llama is a small beast of burden noted for being sure-footed 

 under a heavy load. General Bolivar (1783-1830) estimated that 

 early in the nineteenth century as many as 300,000 llamas were used 

 for transportation in the mining districts of Potosi alone. Since that 

 time the horse and mule have come into more general use. 



Cat. No. 181,310 U.S.N.M. 



Model of Horse for Burden and Traction. (Scale 1 : 6.) Made in the 



Museum. 



The horse was domesticated and used as a beast of burden before 

 the dawn of history. Since the era of improvement in roads and in 

 the construction of vehicles with wheels, the number of horses used 

 for traction has greatly increased in both hemispheres. The domesti- 

 cation of the horse, now found in nearly every part of the world in- 

 habited by man, and the adaptation of that animal to various methods 

 of transportation, has exercised a very important influence upon the 

 advancement of civilization. Cat. No. 181,332 U.S.N.M. 



