584 Transactions of the American Institute. 



turning of a car, can only be ascertained by trial. It would seem to 

 require so much, lateral motion of the car before it could be brought 

 at right-angles to the next car, that perhaps it would force it from the 

 track before it could uncouple. 



Mr. Partridge stated that the plan of preventing the play between 

 the cars made it necessary in starting that all should be started 

 simultaneously, which was a severe strain upon the engine. In this 

 coupling, however, the drawing springs, while preventing- any " lost 

 motion," relieved the engine from the strain of starting the whole 

 train at once. 



Mr. Boyle said that his plan was objected to for the reason that it 

 allowed the overturned car to separate ; and it was thought that it 

 should be held on the track by the remaining cars. 



Mr. T. D. Stetson — There seems to be no doubt now that, practi- 

 cally, it is desirable to disconnect a car which gets off the track. It 

 is now believed to tend to the safety of the disabled car ; and, as to 

 the others, there is no question but it adds to their safety. The 

 Baltimore and Ohio railroad for a long time have used a wooden 

 coupling, strapped with iron, so that it should twist and break when 

 the car got out of line. There is much force in the objection that 

 before the car can be turned over, it must necessarily be moved a con- 

 siderable distance laterally. 



Mr. Partridge — I think that that motion would cause this coupling 

 to disconnect by opening the- side springs and clearing the link from 

 the jaws. 



The following paper was then read by the author : 



Electko-magnetism. 



By Prof. John Phin — At the meeting of the British Association 

 last September, a paper was read by Rev. 11. Highton, which has 

 attracted a great deal of attention both in Europe and in this country, 

 particularly among persons fond of reading about scientific pursuits, 

 and who imagine that the field of discovery is almost unlimited, but 

 the foundation of whose knowledge has not been laid broad and deep. 

 The paper of Mr. Highton was to the effect that the old ideas of cor- 

 relation of forces are entirely erroneous, and, therefore, are not to be 

 taken into account in any calculations upon the application of heat, 

 electricity or any other force, for motive power. We shall get his 

 views more clearly by reading the opening passage of his paper con- 

 tributed to the January number of the Quarterly Journal of Science. 

 He says : 



