132 ANNUAL OF SCIENTIFIC DISCOVERY. 



A New Theory of Churning. Mr. E. Conkling, through the Ohio Cultivator, 

 makes the following suggestions on the true philosophy of churning: "The 

 plan is to inject the cream into itself or against a hard substance, with great 

 force, by means of a sort of force pump, thereby producing concussion suffi- 

 cient to rupture the globules, and produce speedy and perfect comminution of 

 the butterine particles." 



Implement for Cutting down Trees. An implement recently*invented by 

 S. C. Ehrsam, of New York, consists in giving a rotating motion around the 

 body or trunk of the tree, to a cutting blade ; also, in giving to the blade a 

 feed motion into the tree, by means of an annular rack or toothed rim, and a 

 spiral thread. The rack or toothed run is attached to a collar, which is fitted 

 around the trunk of the tree, the screw thread being cut on the upper edge of 

 the collar, and fitting in or between corresponding threads on the under side 

 of the chisel or cutter. Power being apph'ed, the cutter revolves around the 

 tree, and cuts inward, until the trunk is severed. 



