with a tensile strength as great as mentioned will give a result which is
perfectly satisfactory in almost all cases.

There are a great many jobs where it is possible to fill up the weld, that
is, make the section at the point of the weld a little larger than the
section through the rest of the piece. By doing this, the disadvantages
of the weld being in the form of a casting in comparison with the rest of
the piece being in the form of rolled steel can be overcome, and make the
weld itself even stronger than the original piece.

The next question is the adaptability of the electric arc in comparison
with forge fire, oxy-acetylene or other method. The answer is somewhat
difficult if made general. There are no doubt some cases where the use of a
drop hammer and forge fire or the use of the oxy-acetylene torch will make,
all things being considered, a better job than the use of the electric arc,
although a case where this is absolutely proved is rare.

The electric arc will melt metal in a weld for less than the same metal can
be melted by the use of the oxy-acetylene torch, and, on account of the
fact that the heat can be applied exactly where it is required and in the
amount required, the arc can in almost all cases supply welding heat for
less cost than a forge fire or heating furnace.

The one great advantage of the oxy-acetylene method in comparison with
other methods of welding is the fact that in some cases of very thin sheet,
the weld can be made somewhat sooner than is possible otherwise. With metal
of 18 gauge or thicker, this advantage is eliminated. In cutting steel, the
oxy-acetylene torch is superior to almost any other possible method.

_Arc Welding Machines._--A consideration of the function and purpose