742 TRANSACTIOyS OF THE AilEEIC AN INSTITUTE. 



yarn eveiy time the direction of the needles ai'c changed. Thus 

 ^ve are enabled to knit forward and back, and can knit a complete 

 and firm heel better than any machine now offered to the public. 



CORN EAR VESTER. 

 A model of ButterAvorth's corn hai-vester was then exhibited 

 and explained. It is propelled by a single horse, who walks between 

 two rows of corn, and these rows are gathered by the machine, cut 

 by attached blades which are fixed at angles near each wheel; the 

 corn when gathered is dropped in bundles which may be varied at 

 pleasure. Twelve to fifteen acres of corn per day can be gathered 

 by one of these machines. This machine was invented by T. But- 

 terwoi-th, of Quincy, 111., and patented on February 6, 1866. 



BIL GE- WA TER INDICA TOR. 



Brevoor's improvement on Shaler's bilge-water indicator was 

 then showm. It consists of a small dial, having an indicator hand 

 attached, and operated by a gear and flexible valve behind the 

 dial. A tube leads from this valve into the hold of the vessel. 

 As soon as the end of the tube comes in contact with water, the 

 air contained in the tube is compressed, and acting on the valve, 

 is indicated by the hand upon the dial. 



Ml-. Walling showed some small metallic caps or covers which 

 had their flanges split in small sections, and inquired the cause. 

 As these caps were formed by spinning, and then electro-plated, it 

 was suffsested that the evil was done in the act of turnino^ the 

 edge when being spun by the workman, but not made visible until 

 electro-plated and polished. 



After some discussion, the meeting adjourned for one week. 



November 14, 1867. 



Prof. S. D. Tillman in the chair; J. Wtatt Reid, Esq., Secretary. 



The Chairman read the following notes on scientific progress: 



MASTIC CEMENTS. 



According to Bottger, these cements are mixtures of 100 parts 

 of sand, limestone, and litharge (yellow protoxide of lead), with 

 seven parts of linseed oil. At first the mixture has little coher- 

 ence, but w^hen pressed it gradually acquires the hardness of ordi- 

 nary sandstone. 



