Note 170 — Chapter XIX · THE ENCOURAGEMENT AND REGULATION OF COMMERCE.

In illustration of this it may be mentioned that in all the years from 1000 A. D. to 1750 A. D. there were only three inventions of remarkable value or interest; namely, printing, gunpowder, and the steam engine. But what of the period since 1750? The railroad, the steamship, the telegraph, the cable, the telephone, radio communication, the electric light, the electric motor and the trolley, the submarine, the airplane, the cinematograph, the phonograph, the internal combustion engine and motor vehicles of all kinds, the X-ray, and so on. These, moreover, are only the landmarks of mechanical progress, which is a relatively small item in the sum-total of human advance.