TRANSACTIONS OF THE SECTIONS. 135 
stand, without dropping or opening at the rolls, a degree of heat ca- 
pable of compactly and adhesively welding the piles together, so as to 
prevent exfoliation or a separation of the parts when subjected to 
railroad traffic. 
The qualities most essential for railway iron being fibre and hardness, 
the attention of the author has been especially directed to the manner 
of iron having all these qualities in the highest possible degree. 
Mr. Mushet considers that the greatest possible quantity of fibre, 
with a superior degree of hardness and durability, may be produced by 
avoiding the process and waste of the refinery. The pig iron is to be at 
once introduced into the puddling furnace, where being subjected to 
a temperature just sufficient for fusion, some finely-ground rich iron 
ore is thrown upon it and worked by the puddler into the iron. The 
usual process of the hammer and the rolls is then gone through. 
Several specimens of iron made at different works were exhibited. 
On the Teeth of Wheels. By Rozpert Witxis, M. A., Jacksonian 
Professor in the University of Cambridge. 
Two wheels set out by the common plan, with epicycloidal teeth at 
the same pitch, will work perfectly well; but a third wheel of different 
diameter, with teeth at the same pitch, will not work with either of them. 
To obviate this circumstance, Professor Willis proposes that the 
teeth should be described on the following principle: If two pitch lines 
be taken, and a tracing circle of any diameter, and an external epicy- 
cloid be traced on the driver, and an internal epicycloid on the driven 
wheel, the teeth will move each other truly. Professor Willis exhibited 
also a form of tooth peculiarly applicable to cranes, or wherever the 
work is only one way and great strength is required. 
On the Construction of Vessels with Safety Keels. By Mr. Lane, 
of her Majesty's Dock Yard, Woolwich. 
On a New Perspective Drawing Board for Mechanical Drawings. 
By Mr. Krncs ey. 
On Canals and Railways in America. By Professor Henry, 
Prince Town College. 
Professor Henry gave a most interesting account of the internal 
communication in the United States, and presented to the Section a 
map, showing the canals and railways complete or in progress. It 
appears that 2000 miles of canal and 1800 miles of railway are com- 
pleted, and that near 3000 miles of railway were in progress; for par- 
ticular accounts of which he referred to the American Almanac. 
