Proceebings of the Polytechnic Association. 865 

 November 19, 1868. 



Professor S. D. Tillman in the chair ; Mr. C. E. EiiERY, Secretary. 

 Fire-Proof Work. 



Mr. William A. Berkey, of Grand Rapids, Michigan, exhibited a 

 model of his plan for constructing fire-proof buildings. The main 

 feature of tliis invention consists in coating the beams, laths and 

 other woodwork with mortar of sufficient thickness to make it 

 impervious to fire. A building twenty feet wide and two hundred 

 deep would cost from $250 to $400 a floor. The mortar passes all 

 around the beam, so that the shrinkage of the wood is not of much 

 consequence. 



New Kerosene Lamp. 



Mr. John Russell exhibited and explained a new kerosene burner. 

 This burner, he said, is so simple that it cannot get out of order, and 

 admitting, as it does, the free access of air and light below the point 

 of burning, the combustion is perfect, and explosion impossible j 

 while the absence of the usual brass obstructions in the chimney 

 allows the light to shine down as well as up, thus giving double the 

 light from the same quantity of oil, and giving it where it- is most 

 needed. The chimney goes on without spring or screw. 



Kew Horse Hat Rake. 



Mr. Charles IST. Goss exhibited a model of a wheeled horse hay 

 rake, in which the rake, arranged in front of the axle, consist-s in a 

 series of curved wooden teeth, each tooth attached by a spring joint 

 to a separate carrying bar, and the whole lifted, when desired to drop 

 the accumulated hay, by means of a lever frame arranged in suitable 

 position in front of the driver's seat. ^ 



Earthquakes. 



The discussion on this subject was opened by Dr. J. J. Edwards, 

 who occupied the greater part of an hour in attempting to prove 

 that the principal cause of earthquakes was electricity. He spoke at 

 length on the correlation of forces, the structure of serolites, and the 

 internal condition of the earth, quoting from varixjiis 'ailthors to sup- 

 port his position. 



At the conclusion of the paper. Dr. Parmelee gave an explanation 

 of the rupture which sometimes occurs in Leyden , jars by the dis- 



[Inst.] . 55 



