PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 505 



JVeio Subject. — On motion of Mr. Fisher, the subject of " Modes 

 of Blockade," was suggested for the ensuing meeting. 

 Adjourned. 



American Institute, Polytechnic Association, } 



February 5, 18G2. j 

 Prof. Seely in the chair. 



franklinite plates. . 



Mr. Selleck exhibited a specimen of five plates of wrought iron, 

 cemented together with Franklinite. 



Mr. Dibben. — Were the plates cleaned beforehand ? 



Mr. Selleck. — There was no preparation of the plates whatever. 

 The scale was all on. I think it might be better to scale it. It 

 was thrown into water after it was rolled, when a little more 

 than cherry red. It would not be so hard if it was left without 

 being thrown into water. The Franklinite hardens like steel. It 

 can be as easily shaped and worked as iron. I do not think it is 

 so liable to rust as ordinary iron or steel. This mass was rolled 

 while the Franklinite was in the fluid state, and the combined 

 mass can be rolled as rapidl}' as ordinary iron. There is no extra 

 work upon the plates. This article is applicable to buiglar-proof 

 safes, mould-boards for plows, hoes, shovels, &c., — to any wearing 

 surfaces. 



Mr. Dibben. — Suppose you wanted to weld a shank to that 

 specimen ? 



Mr. Selleck. — The combination can be welded as well as any 

 other form of iron. I have taken a nail rod, melted Franklinite 

 upon it, doubled it over, drawn it out, and had a razor made out 

 of it. Cold chisels have been made in the same way. The 

 Franklinite steel becomes^hafder when tempered, than any other 

 steel I have ever seen. A quantity of it was sent on to Mr. Alger, in 

 Boston, and he used it for tools in boring out cannon. He had 

 the temper drawn six times, and the tool then stood six or eight 

 times longer than the best English steel he had ever tried. There 

 is some mystery yet about the hardening of Franklinite steel. I 

 think it hardens better in a current of air than in water. I have 

 had a good deal of trouble in getting it soft enough to work. 



Mr. Dibben. — How long are your sheets of iron and Franklinite 

 subjected to heat in this process ? 



Mr. Selleck. — The Franklinite melts almost instantly. 



