Examples of this include an illustration of the magnetic field of a bar magnet in a telegraphone
and an illustration of how early cameras projected an image through a pinhole aperture.
1899 marked the beginning of the first revolution in magnetic recording technology as Valdemar Poulsen of Denmark invented and patented the first true magnetic recorder, the Telegraphone
In the summer of 1898, the Danish telephone technician Valdemar Poulsen invented the telegraphone, the world's first functional magnetic recorder.
Given the eventual success of magnetic recording, why were Poulsen and his collaborators in Denmark and abroad unable to develop the telegraphone into a commercial product?
In contrast, the problems Poulsen and his collaborators faced were not resistance, (all participants were enthusiastic about the telegraphone and its prospects) but a failure in focus and direction, brought about by the geographic and cultural circumstances associated with the invention's birth.
Second, Poulsen, his fellow Danes, and the German firms they worked with were primarily interested in finding some application for the telegraphone within the telephone system.
2) The phonograph stored sound energy as grooves of varying depth; the Telegraphone took advantage of the microphone, a device adapted from the telephone, and the induction coil.
The Telegraphone was a grand prize winner at the 1900 International Exposition in Paris, and it received a great deal of praise from the technical press and from scientific organizations like the Smithsonian Institution in Washington, D.
Although it retained the basic recording principle of the Telegraphone, the BBC machine represented a much higher state of refinement, particularly in its use of the newly developed electronic amplifier.