228 METALLURGY OF CAST IRON.
ing the phosphorus, is also a factor that must have an ;
effect in strengthening the iron. The increase of ;
combined carbon causes greater contraction but less chill, a peculiarity due, no doubt, to the fact that hot metal will chill deeper than dull metal, as shown in Chapter LVI. However, the ends cast against chills were very dense and hard. Tests Nos. i to 6, with their analyses, were made by Dr. R. Moldenke at the McConway & Torley Co., Pittsburg, Pa., and tests Nos. 7 to 11 by the author, and the analyses by Mr. H. E. Diller at the Pennsylvania Malleable Co., Pitts-burg, Pa.
There are several methods of adding phosphorus to molten iron. The simplest plan consists in introducing the phosphorus with the hand or with tongs. There need be no fear of the dampness on the sticks as they are taken from the water, for as long as water is on top of the metal no harm can result. Care should be taken in handling phosphorus by hand to do it quickly, as it ignites in a little more than one minute when exposed to the air and serious burns'have resulted from careless handling. Another method used by some is to take a rod, to one end of which is secured a dried clay or graphitic core having a ^-inch hole extending into one end six to seven inches deep. Into this hole the phosphorus stick is inserted and held by means of sticking a few strips of tin or copper in the vacant space. Still another plan is to take a piece of gas pipe about three feet long, with a hole a little larger than the sticks of phosphorus, and after the phosphorus is inserted place a plug of tin about one-eighth of an inch thick to fit tightly into the end of the pipe. While introducing the end of the pipe into the molten metalthe above bars, described in Tables 31 andthe so-The philosophical explanation of this extraordinary effect i my opinion, to be found in the fact that the f erro-manganesu .ğR. C. Hindiey, M. Hoskins, Harvard College, Havemeyer University, Henry Hiels Chemical Co., Isabella Furnace, Iron Gate Furnace, Iroquois Iron Co., Illinois Steel Co., Jefferson Iron Co., Kittan-ning Iron & Steel Co., C. A. Kelly Plow Co., Lebanon Furnace, Longdale Iron Co., Lackawanna Iron & Steel Co., Logan Iron........................ 16,720 " t-