Despite the progress of wireless telegraphy it has not yet supplanted the submarine cable and the land wire, and in conservative opinion it will be many years before it will do so.  In fact, since Marconi’s work there has been no diminution in the number or amount of cables laid and the business handled, nor is there prospect of such for years to come.  While the cable has answered admirably for telegraphic purposes yet for telephony over considerable distances it has failed entirely so that wireless telephony over oceans starts with a more than favorable outlook.  But wireless telegraphy to a large extent has made its own field and here its work has been greatly successful.  Thus when Peary’s message announcing his discovery of the North Pole came out of the Frozen North, it was by way of the wireless station on the distant Labrador coast that it reached an anxious and interested civilization.  It is this same wireless that watches the progress of the fishing fleets at stations where commercial considerations would render impossible the maintenance of a submarine cable.  It is the wireless telegraph that maintains communication in the interior of Alaska and between islands in the Pacific and elsewhere where conditions of development do not permit of the more expensive installation of submarine cable or climatic or other conditions render impossible overland lines.  At sea its advantages are obvious.  Everywhere the ether responds to the impulses of the crackling sparks, and even from the airship we soon may expect wireless messages as the few untrodden regions of our globe are explored.

CHAPTER XL

Electro-chemistry and electro-metallurgy.

In no department of the application of electricity to practical work has there been a greater development than in electro-metallurgy and electro-chemistry.  To-day there are vast industries depending upon electrical processes and the developments of a quarter of a century have been truly remarkable.  Already more than one-half of the copper used in the arts is derived by electrolytic refining.  The production of aluminum depends entirely on electricity, the electric furnace as a possible rival to the blast furnace for the production of iron and steel is being seriously considered, and many other metallurgical processes are being undertaken on a large scale.  We have seen in our chapter on Electrolysis how a metal may be deposited from a solution of its salt and how this process could be used for deriving a pure metal or for plating or coating with the desired metal the surface of another metal or one covered with graphite.  In the following pages it is intended to take up some of the more notable accomplishments in this field achieved by electricity, which have been developed to a state of commercial importance.