Almost every house of any pretension possesses such a wire.

Leading me into the next apartment, my friend pointed out an immense number of instruments of a box-like shape, with a slit in which a leaf of about four inches by two was placed.

These were constantly ejected and on the instant mechanically replaced.

The fallen leaves were collected and sorted by the officers present, and at once placed in one or other of another set of exactly similar instruments.

Any one possessing a private wire can write at his own desk in the manual character a letter or message on one of these slips.