460 TRANSACTIONS OF THE 



pay for more coal than what by its consumption would generate power 

 enough to pump up all the water which the city would require. 



Mr. Baker. — Air might be forced through pipes to convey power in or 

 through a city. It has been so forced for other economical purposes. 

 Beer must be cooled quickly, and to do so a blower was employed to force 

 a current of air through tubes over the beer. This cooled the beer down 

 to 60° in seven minutes, though when allowed to cool in the old plan it 

 took 18 hours. 



After some further irregular discussion, the subject for nest evening was 

 selected, viz : " Telegraphing," and the Association adjourned. 



Polytechnic Association or the American Institute, ) 



Seplemhcr 15th, 1859. ) 



Professor Mason, Chairman. John Johnson, Secretary, pro tem. 



A sketch of the rail-road route from Boston to Troy, through the Hoosic 

 tunnel, was presented from Edward W. Serrell, Esq., the engineer of the 

 tunnel. Major Serrell also wished to call attention to his system of in- 

 creasing the traction of locomotives by means of magnetism. The driving 

 wheels of a locomotive are arranged as magnets, at a cost of four hundred 

 dollars for each locomotive. A locomotive so managed was in action, and 

 though weighing only 32 tons, it had a traction power of 17 tons, and was 

 able to pull a locomotive not so arranged backwards, though weighing 40 

 tons. 



Mr. Tillman considered it impossible to magnetize the wheels of a loco- 

 motive so that they should be available for the purpose named. Others 

 had tried to do so as well as Major Serrell. 



Mr. Johnson. — As time is an important element in the affairs of men, if 

 polarity have to be induced in iron and changed in Mr. Serrell's plan, 

 it will be utterly impossible to avail ourselves of any appreciable amount 

 of magnetism in the time required to make it available. 



Mr. Tillman. — Time is of vast importance in these machines, and many 

 have failed through disregarding it. Vergnes, for instance. 



Professor Hedrick. — I regard the whole matter as practical, but it is not 

 well to discuss this matter until we have Major Serrell present, and actually 

 know something about his plan. 



Mr. Stetson. — The application of magnetism to increasing the traction 

 power of an engine is of vast importance, particularly for ascending grades. 



Mr. Garvcy. — When the traction force is liable at anytime to amount to 

 17 or 18 tons, a locomotive must be made of 40 or 50 tons weight. This 

 enormous weight moving along a rail road at a speed of 20 or 80 miles an 

 hour, is sufficient to shatter itself and the road, for the we'ghtier the engine 

 the greater is its own wear, and the more injury does it do the road The 

 plan of increasing the traction under discussion is described in the papers 

 as a " shifting polarity in the driving wheels." We know that to slide an 

 armature from a magnet is comparatively an easy matter, but to draw it off 



