Page:Arthur B Reeve - The Dream Doctor.djvu/209

 titled, 'The telegraphone'll get you, if you don't watch, out.' This is the latest improved telegraphone, a little electromagnetic wizard in a box, which we detectives are now using to take down and 'can' telephone conversations and other records. It is based on an entirely new principle in every way different from the phonograph. It was discovered by an inventor several years ago, while experimenting in telephony.

"There are no disks or cylinders of wax, as in the phonograph, but two large spools of extremely fine steel wire. The record is not made mechanically on a cylinder, but electromagnetically on this wire. Small portions of magnetism are imparted to fractions of the steel wire as it passes between two carbon electric magnets. Each impression represents a sound wave. There is no apparent difference in the wire, no surface abrasion or other change, yet each particle of steel undergoes an electromagnetic transformation by which the sound is indelibly imprinted on it until it is wiped out by the erasing magnet. There are no cylinders to be shaved; all that is needed to use the wire again is to pass a magnet over it, automatically erasing any previous record that you do not wish to preserve. You can dictate into it, or, with this plug in, you can record a telephone conversation on it. Even rust or other deterioration of the steel wire by time will not affect this electromagnetic registry of sound. It can be read as long as steel will last. It is as effective for long distances as for short, and there is wire enough on one of these spools for thirty minutes of uninterrupted record."