He told the story of the tests made at the Centennial, and assured the sceptical scientists that he had not been deceived.

"All this my own ears heard," he said, "spoken to me with unmistakable distinctness by this circular disc of iron." The scientists and electrical experts were, for the most part, split up into two camps.

Some of them said the telephone was impossible, while others said that "nothing could be simpler." Almost all were agreed that what Bell had done was a humorous trifle.

But Lord Kelvin persisted.
He hammered the truth home that the telephone was "one of the most interesting inventions that has ever been made in the history of science." He gave a demonstration with one end of the wire in a coal mine.

He stood side by side with Bell at a public meeting in Glasgow, and declared: "The things that were called telephones before Bell were as different from Bell's telephone as a series of hand-claps are different from the human voice.