Note 4 — ANNO DOMINI 2071.

“If any art more than another,” said I, “is calculated to illustrate the fact that the most important discoveries—such as have been most universally brought to bear upon the joint social condition of mankind—have simply resulted from the inventions of scientific men who never dreamt of the practical application of their discoveries; if any such thing exists, surely it is the telegraph. Could these magic wires have lurked in the mind of Thales when he found out, now twenty-five centuries ago, that a piece of amber, when rubbed, attracts light bodies, even although it led him to discover the very first of those phenomena, the cause of which must be sought in that mysterious power which now we call electricity? Did Galvani think of the telegraphic art when he noticed how the muscles of his frogs contracted under the influence of electricity?4 or Volta, when, following up Galvani’s experiments, he produced the pile that bears his name? And yet that was, so to speak, the embryo of those modern batteries of ours whence proceeds the marvellous action along the wire. Nor is it in any way presumable that Oerstedt ever thought of the application of his discovery to telegraphy, when he first noticed that the magnetic needle is deflected under the influence of electricity;5 no more than Arago, who found that iron becomes magnetic when an electric current runs along it through a metal wire.