“And now, should you like to see how the telephone works in every-day matters?”
On our replying in the affirmative, Thorwald turned a switch, waited a moment, turned it again, and then there appeared before our eyes a familiar object, nothing less than the ship in which we had made our recent voyage. A number of the men, whom we recognized, were walking about the deck, and one stood apart, near the side of the vessel, conversing with Thorwald, the words of both being audible to us. When they were through, the scene faded away and Thorwald said:
“As soon as the ship reached its dock connection was made with the general system of wires, and the instrument, which is stationed near the place where the man was standing, was ready for use.
“So, whenever we desire to talk to our friends, we summon them to our presence. You see it is not necessary to speak directly into the transmitter. We can sit comfortably in our chairs and converse as easily as when our friends are actually present.”
“Let me ask you, Thorwald,” said the doctor, “how all the electricity you use is generated? The immense quantity you employ must necessitate a great deal of power to produce it. Is there a huge plant in every city driven by steam?”
“No,” answered Thorwald. “We make no use of steam in these days. All the power we need is obtained from natural waterfalls and rapids. This power, which nature has placed ready made at our hand, is so abundant that it can never be exhausted.”
“These waterfalls must fortunately be well distributed,” remarked the doctor.
“Not more so, I presume, than on the earth,” Thorwald made answer. “Every stream that runs in its bed has in it a power proportioned to the volume of water and the swiftness of its current. Think of the amount of water wasted every day in this way—no, not wasted, but unused. We do not need, however, to utilize ordinary streams, as there are enough great falls where power is transformed into electricity to be sent over wires to any distance required. In every city or district large storage facilities are provided from which power can be obtained for all possible purposes. Our beds of coal and wells of oil were long since exhausted, but while rain falls and water runs this power can never fail us.
“Doctor, what is the best metal you have for transmitting electricity?”
“Copper,” answered my companion. “Silver is a little better conductor, and a new metal, called glucinium, is better still, but both of these are too expensive for general use. Our telegraph and telephone wires were formerly made of iron for the sake of economy, but copper is now used for these lines, as well as for distributing electricity on a large scale. The copper wire now commonly used for the telegraph has a resistance of something like four ohms to the mile.”