5T2 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Mr. Laman. — The larger the gun the more need there was of 

 an accelerator. 



Mr. Hamaker, of Lancaster, Pa., presented a new mode of bal- 

 ancing mill wheels, and said, this is a new mode of applying the 

 the balance to a millstone to get it to a perfect balance, both in 

 running and standing. The way of balancing mills heretofore 

 was by balancing lead on the top of the stone, which I find was 

 not the proper way. Nine out of ten when suspended, are out 

 of balance, and the balance is generally below the suspension 

 line. By my mode of balancing, the balance can be made both 

 running and standing. The balance should be applied directly 

 in a level with the heavy portion of the stone. I have applied 

 it to about eighteen mills in Lancaster, Pa., and to three in Phila- 

 delphia. D. Fellenhamer is the patentee, and took out his pa- 

 tent on February 4, 1860. 



Mr. Dibben said the only difference from the old way was that 

 the weight was placed at the bottom instead of the top, as in the 

 old plan. 



Dr. Yander Weyde. — At the last meeting we had the subject 

 of projectiles. Experiments have been tried in Germany to find 

 the effect of a ball in its rotation. Balls rotate on the centre of 

 gravity. If a ball is so placed in a gun that the left side is the 

 centre of gravity, the effect will be that the ball will deviate to- 

 wards that side. If so placed that the centre of gravity be on 

 the right side, then it will deviate towards that side. If the 

 centre of gravity be placed on the top, it will go farther than if 

 it was on the centre. Every ball will rotate round its shortest 

 axis. The tendency to rotate round the shortest axis, will make 

 it rotate against gravitation. He tried an experiment with a 

 glass globe containing mercury and wine. The mercury being 

 the heaviest, kept next the glass, the wine remained in the cen- 

 tre, and the bottom was free from both. He made other experi- 

 ments with rings and a chain, for the purpose of showing that 

 everything rotated round its shortest axis. 



Dr. Stevens. — In the discussion the last evening the question 

 was asked why the small particles of coal did not burn. I think 

 the reason is that a sufficient quantity of atmospheric air is not 

 furnished to the stove. A gentleman of Boston, has invented a 

 plan by which a sufficient quantity of hot air is furnished. 



