PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 649 



stroke, the distance the car would travel between charging sta- 

 tions may be increased 100 per cent under ordinary circum- 

 stances." 



The tables referred to, of which there are three, are designed 

 to show — 



First, Me /o/a//orce, in pounds, required to impel at different 

 given velocities, on given grades, a single car, estimated with its 

 load at seven tons, with a receiver of 65 cubic feet capacity, 

 and with two cylinders, each five inches diameter and fourteen 

 inches stroke, worked non-expansively. 



Second, average pressure, in pounds per square inch, required 

 in cylinder to impel the car at similar velocities, on similar 

 grades ; and 



Third, distance which may be traveled without re-changing at 

 20 miles per hour on similar grades at given pressures on the 

 pistons. 



I thank you, Mr. Chairman and gentlemen, for the earnest 

 attention you have given to this subject, and trust that, in 

 accordance with your design of standing between the imagina- 

 tive and over-zealous projector or advocate of new theories and 

 the great public, in which the latter is sometimes in danger of 

 suffering at the hands of the former, you will favor me with some 

 expression of your judgment upon the merits of the proposition 

 thus submitted to your consideration and decision. 



The President believed that the most effective mode of propul- 

 sion would have to be adopted in this city, and whatever that 

 mode might be, the least desirable would be found to be horse- 

 power, which would be abandoned. He suggested that the 

 report be referred to a committee, and a motion was made and 

 adopted accordingly. The gentlemen appointed on the commit- 

 tee were Messrs. John Johnson and J. K. Fisher. 



NOVELTY CHURN. 



J. E. "Walter exhibited a churn patented in 1859. Sweet milk 

 is churned at a temperature of 62 deg. inside of five minutes, 

 leaving the milk as sweet after churning as before. The milk is 

 taken just after the animal heat has left it, and put into the 

 churn. The churn has a double bottom ; milk is put into tho 

 upper chamber and water in the lower one. In cold weather 

 warm water is put in. A thermometer fixed in the end of the 

 box indicates the temperature which should be 62 deg. ; when 



