180 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
gentleman managing one of the large American steel companies, who 
has just returned from an inspection of the different electric steel 
furnaces operating in Europe, tells me that he considered the Stassano 
furnace as doing the best work, all around, of all the furnaces he saw 
in operation. I have seen this furnace operating smoothly and regu- 
larly in Turin, producing steel for castings which were being sold in 
competition with open-hearth and Bessemer steel castings in the open 
market. The single arc furnace is best illustrated by the Girod © 
furnace, which is built like the body of an open-hearth furnace with 
the electric current entering the bath by carbon electrodes suspended 
above it, and springing arcs to it, while the current leaves the bath 
through metallic conductors passing through the saucer-shaped 
hearth below the level of the metallic surface. These furnaces work 
with great regularity, and a large number are operating in Europe, in 
capacities up to 12 tonseach. Iam informed that the Krupp Works 
at Essen has just contracted to put in five of these of the 12-ton size, 
which would confirm statements made to me by my European friends 
that this furnace is working the best of all the electric steel furnacesnow 
operating in Europe. The double-arc furnace, of which the Heroult 
furnace is the most familiar type, works with two arcs in series, the 
current entering the bath and leaving it also through electrodes 
suspended above it. The general style is that of an open-hearth 
furnace with electrodes passing through the roof. The current used 
is roughly 100 kilowatts per ton of steel capacity, and the largest so 
far operated is 15 tons. A 3-ton furnace of this type was seen by you 
at the Firth-Stirling Steel Works at Demmler, yesterday, producing 
crucible-quality steel. The United States Steel Corporation has 
acquired licenses to operate the Heroult furnace, and has already 
two 15-ton furnaces in operation. Without doubt, the Heroult fur- 
nace is at the present time the most popular and successful electric 
steel furnace in the United States. I have not time to more than 
name the Keller, the Hiorth, the Harmet, the Frick—all of which are 
operating at this present moment in Europe. 
There are other ways of making steel than the crucible method. 
Bessemer steel is the cheapest, and open-hearth steel is next best. 
These two varieties grade into each other in quality, but between 
open-hearth and crucible steel there is an enormous gap in price and 
in quality which is destined to be bridged over by intermediate qual- 
ities of electric steel as it becomes cheaper and is manufactured on a 
larger scale. This will soon become one of thelargeusesof the electric 
method, occupying a field peculiarly its own. It will enable steel 
manufacturers to supply steel better than the best open-hearth prod- 
uct at less than the price of crucible steel. I need not enlarge upon 
the advantages of this to a Pittsburgh audience. 
