POLYTEOHNIC ASSOCIATION PROCEEDINGS. 987 



of their history were almost entirely of a theoretical nature, the 

 problems to be solved requiring abstract mental operations. More 

 recently the method of teaching has been improved by being made 

 more practical. The exercises, instead of being paper calculations, 

 have been transactions, the student being provided with currency 

 and specimens of merchandise for the purpose. 



These practical exercises have ever been regarded with high favor 

 by the most eminent educators and skillful teachers. But in intro- 

 ducing them to any extent an inconvenience resulted, for it became 

 necessary for the* student or teacher to go from one part of the 

 room to another in making exchanges; or it became necessary to 

 employ a number of boj^s to convey packages, remittances, etc., as 

 might be required, either plan being attended by interruptions, 

 noise, and the consumption of time. This improvement consists in 

 introducing a great number of systematized practical transactions, 

 a variety of merchandise and appliances of trade, fitting the room 

 so as to represent commercial centers, and connecting the same by 

 a miniature railway, which fonns a noiseless and easily controlled 

 means of intercommunication with all parts of the hall. By this 

 means the student can sit quietly at his desk and dispatch for any 

 article, or make an exchange in any part- of the room. The labors 

 of the teachers are greatly lessened; a great variety of practical 

 transactions are easily introduced, and the same are dispatched with 

 a celerity, harmony and precision that could be attained in no 

 other way. 



The author read a paragraph from Rutledge S Davidson^s Busi- 

 ness Jourruil, showing the manner in which his improvement is 

 used in teaching commercial transactions, and then said: 



My principal object, however, is to explain the mechanical con- 

 struction of the locomotive, which propels the train above referred 

 to. The general arrangement is as follows: A stationary battery, 

 placed in an adjoining room, supplies the electric fluid, which, being 

 conveyed by the truck to the engine, is the source of power which 

 puts the same in motion. The magnets are ten in number, of the 

 type made use of by telegraph instrument makers in constructing 

 resfisterino; instruments, it beinor ascertained that a large number 

 of small magnets are much more efiective than a few large magnets. 

 They are arranged in pairs, and occupy the space usually allotted 

 to the boiler. The circulation of the electric fluid to the magnets 

 is somewhat peculiar. It is not done by passing the current suc- 

 cessively through the magnets, forming a single circuit, but hj 



