Submarine cables are now in extensive operation in all parts of the world. More than half a dozen cross the Atlantic, and lines have been constructed from England to India, from India to Australia, and from the United States to Mexico and South America. At the present time there are perhaps two hundred cables belonging to companies, and about five hundred belonging to government systems. These cables, all told, cover a distance of nearly a hundred thousand miles.
A recent incident is told that shows something of the greatness of the telegraph. In June, 1897, a great celebration took place in London, in honor of the sixty years that Queen Victoria had been upon the British throne. The Queen rode in a procession through streets packed with millions of people. Just as she left the palace she pressed an electric button. Instantly this message was sent to her colonies all over the world:
"From my heart I thank my beloved people. May God bless them. Victoria, R. I."
To forty different points in her empire sped the electric message. In sixteen minutes a reply came from Ottawa in Canada; then one by one answers came in from more remote provinces; until, before the Queen reached London Bridge, the Cape of Good Hope, the Gold Coast of Africa, and the great continent of Australia had sent responses to her message.
When the telegraph was invented, years ago, it seemed little less than a miracle that a message could be dictated in one city and received almost instantaneously in another city far distant from the sender. Scientists, however, began at once on the invention of something more wonderful. The telegraph lacks in one respect. By it messages must be sent exactly as dictated and cannot be corrected until the reply is received. In a sense, sending and receiving messages by telegraph is a form of conversation, but a conversation at arm's-length. To carry on a real conversation at long distances would be a great advance. An instrument prepared for this purpose would be called a telephone.
In 1875 Alexander Graham Bell invented the first successful electric telephone. This was exhibited at Salem, Massachusetts, and at Philadelphia at the Centennial Exhibition, and a patent for it was obtained. The apparatus of Bell's telephone is very simple, and practically consists of four parts: the battery, the wire which runs from the speaker to the hearer, a diaphragm against which the vibrations of the air produced by the voice of the speaker strike, and another diaphragm at the other end of the wire which reproduces similar vibrations and sends them to the ear of the listener. Elisha Gray of Boston made a similar invention and applied for a patent two hours after Bell's application was filed. The invention of Mr. Bell has proved a decided success. All telephonic operations, since this invention, have been based upon the instrument which he patented in 1876.