Advances in Telegraphy
Advances in TelegraphyModern Electrical Inventions:
The mechanical improvements in telegraphy have been so rapid that at present a single operator can easily send or receive forty words a minute. He can telegraph more quickly than the average person can write; and with a combination of the latest improvements the speed can be enormously increased. Recently, 1500 words were flashed from New York to Boston over a single wire in one second.
In actual practice messages are not ordinarily sent long distances over a direct line, but are automatically transferred to new lines at definite points. For example, a message from New York to Chicago does not travel along an uninterrupted path, but is automatically transferred at some point, such as Lancaster, to a second line which carries it on to Pittsburgh, where it is again transferred to a third line which takes it farther on to its destination.
A Commercial Use of Carbon Dioxide
Magnetic Properties of an Electric Current
How Refraction Deceives us
The Principle of the Windmill
How much is a Stream Worth
The Weight of the Air
Experiments which grew out of the Voltaic Cell