the principles the following questions will be answered:

What metals can be welded by the electric arc?

What difficulties are to be encountered in applying the electric arc to
welding?

What is the strength of the weld in comparison with the original piece?

What is the function of the arc welding machine itself?

What is the comparative application of the electric arc and the
oxy-acetylene method and others of a similar nature?

The answers to these questions will make it possible to understand the
application of this process to any work. In a great many places the use of
the arc is cutting the cost of welding to a very small fraction of what it
would be by any other method, so that the importance of this method may be
well understood.

Any two metals which are brought to the melting temperature and applied to
each other will adhere so that they are no more apt to break at the weld
than at any other point outside of the weld. It is the property of all
metals to stick together under these conditions. The electric arc is used
in this connection merely as a heating agent. This is its only function in
the process.

It has advantages in its ease of application and the cheapness with which
heat can be liberated at any given point by its use. There is nothing in
connection with arc welding that the above principles will not answer; that