In a journal entry written during June 1871 Ralph Waldo Emerson provides an insightful summary of key scientific and engineering discoveries of the Nineteenth Century:
In my lifetime have been wrought five miracles, — namely, 1, the Steamboat; 2, the Railroad; 3, the Electric Telegraph; 4, the application of the Spectroscope to astronomy; 5, the Photograph; — five miracles which have altered the relations of nations to each other. Add cheap postage; and the mowing-machine and the horse-rake. A corresponding power has been given to manufactures by the machine for pegging shoes, and the power-loom, and the power-press of the printers. And in dentistry and in surgery, Dr. Jackson's discovery of Anæsthesia. It only needs to add the power which, up to this hour, eludes all human ingenuity, namely, a rudder to the balloon, to give us the dominion of the air, as well as of the sea and the land. But the account is not complete until we add the discovery of Oersted, of the identity of Electricity and Magnetism, and the generalization of that conversion by its application to light, heat, and gravitation. The geologist has found the correspondence of the age of stratified remains to the ascending scale of structure in animal life. Add now, the daily predictions of the weather for the next twenty-four hours for North America, by the Observatory at Washington.