William Thomson discovered and formulated "the law which governs the retardation of electrical signals in submarine lines." Whitehouse found that with a line 1125 miles long, a signal required a second and a half for transmission. Thomson's law showed that on a line long enough to connect Ireland with Newfoundland the transmission of a signal would require six seconds. This meant a dismally limited service. Only a few words could be cabled in an hour. The croakers were pleased. The men whose habit it is to say "I told you so" were joyous. The financiers would use their capital for other purposes. But Cyrus Field of New York found the money, and William Thomson found the way to utilize his own law to make success out of what had seemed to others to be defeat. He invented the "Siphon Recorder." Then the cable was laid under the Atlantic, and on August 17, 1858, Thomson's instruments sent and received this message:
"Europe and America are united by telegraph. Glory to God in the highest, and on earth peace and goodwill toward men."
Two weeks later the cable broke. The world jeered and lost faith, according to its habit. Some called the cable undertaking "a swindle", some "a hoax", some a silly toy. These were thoughtful critics. Eight years passed, eight years of effort to make and submerge a cable that would endure. In 1866 the difficulties were overcome. The world congratulated itself and the men who had worked the "miracle." Lord Kelvin told me the story as if it had been a little affair of the day before. "There has been so much to think of since then," said he, "and there is so much more to be done! Harnessing Niagara is one thing." The men who plan things and do them were already planning for that, and as in the cable project, they called in Lord Kelvin to help.
"How far can we transmit electricity for power and lighting purposes?" they asked.
"Three hundred miles," said he.
They laid their plans for a much shorter distance, within a hundred miles, and they thought that Kelvin was dreaming. Years later, when power and lighting current had been successfully conveyed over much greater distances than Kelvin had suggested, an acquaintance of mine asked him: "Why did n't you tell us that electric power can be conducted over these greater distances? I thought three hundred miles was the limit."
"The limit is not known," replied Lord Kelvin. "In the case you refer to, I answered a specific question regarding a specific plan undertaken for commercial purposes. The limit was improved by time and circumstance, not by Nature. Ten years ago we could not build the machinery that is built to-day, nor, on a great scale, employ the conductors that are used to-day. My suggestion concerned the means then known, not the means that might be developed in a decade."
"Well, I lost a chance," said the would-be investor, who was also a Scot.
"So, I imagine, did the capitalists of Archimedes' day. You will remember that they failed to provide him with a fulcrum," said Lord Kelvin dryly.
Lord Kelvin, when a young man, became permanently lame as the result of a skating accident, but his lameness did not retard his physical activity. Sir William Ramsay, the celebrated chemist who had been a pupil of Kelvin, said that it "lent emphasis to his amusing class demonstration of 'uniform velocity' when he, Kelvin, marched back and forth behind his lecture-bench with as even a movement as his lameness would permit; and the class generally burst into enthusiastic applause when he altered his pace, and introduced them to the meaning of the word 'acceleration.'"