AMERICAN INSTITUTE. 491 



clul) not to despise tliem. Notwiilistanding the inconceivable power of 

 electricity takes us unawares, in the most unexpected and mysterious man- 

 ner, almost upsetting our intellect, still it is governed by a fixed law, the 

 principles of which we must endeavor to comprehend, taking it for granted, 

 that the Creator has placed our comprehension above, and not under it. 



Mr. Tillman. — How is that in cotton — for wheat grows in wet cotton as 

 well as in straw ? 



Mr. Veeder. — The oil of petrolium is very similar to the Bclmontine 

 article described. At Hamilton, in Canada West, it is found ; at Pitts- 

 burgh, also, 45,000 gallons of it were there for sale recently. It preserves 

 timber ; the oil of it yields white light. By its light in a steamer's cabin, 

 a stereoscopic view was seen almost as bright as by day light. 



Thomas Godwin. — In relation to more safe covering of submarine wires, 

 Bright, of England, recommends a substance which, in the event of frac- 

 ture in the covering can ooze out sufficiently to protect the wire from water, 

 and thus maintain its insulation. I am a plumber, and in the coarse of my 

 experiments in some work at Saltus & Co.'s stores, made some discoveries 

 as to electricity applied to vegetation. Iron filings maybe employed about 

 plants to aid the operation. I find the Boston Year Book of Facts, very 

 useful. 



Mr. Tillman sketched on the black board, a convenient and cheap elec- 

 trotyping apparatus. It consists of a jar of suitable size, with the acid in 

 it, and two pieces — one zinc and the other copper, suspended in the acid — 

 a curve wire attached to the plates at opposite sides of the jar, meeting the 

 ends of the subject of the process immersed in the metallic solution con- 

 tained in a suitable vessel below the jar. 



The Chairman call(?d up the regular subject, " ]>oiler Iron." 



Engineer Stetson. — Some of us here are old stagers, and I shall be pleased 

 if some one, who now sits here silent, will rise and speak to this question, 

 of which we find difficulty in saying any thing new. After much experi- 

 ment of copper and iron lor boilers, we have resorted to the iron, because 

 of its superior strength, although old copper boilers are still valuable for 

 the metal, while old iron boilers are worthless. We want some means to 

 prevent the corrosion of the iron. The mere question of tensile strength 

 has been determined often, and is easy to decide. The mechanism of a 

 boiler demands great attention, for in warming plates, bending, flanging, 

 &c., it receives injurious strains. Charcoal made iron is deemed best for 

 boilers. That of Pennsylvania. — the Juniata. 



Mr. Bruce. — And the Tennessee ! 



Mr. Stetsen. — And the Salisbury ! When I utter an opinion here which 

 does not suit any member, let him knock it [not me) down ! You know that 

 heat up to a certain point, not over 500 degrees of Fahrenheit, adds strength 

 to iron ! and that our boilers very rarely have strain over 350^ ! Govern- 

 ment test of iron shows that our best iron has in square inch rods a tensile 

 strength oi fifty thousand pounds ! 



