Superconducting homopolar generators have been considered as pulsed power sources for laser weapon systems. Faraday's homopolar motor consisted of a permanent magnet sitting in a pool of mercury. However, the direct current homopolar linear motor railgun is another high acceleration linear motor design. The first homopolar generator was developed by Michael Faraday during his experiments in 1831. The homopolar generator was developed first by Michael Faraday during his memorable experiments in 1831. The homopolar motor is driven by the Lorentz force. The homopolar motor was the first electrical motor to be built. DC homopolar machines are among the oldest electric machines. A homopolar motor is very easy to build. Their final decision was to use a homopolar generator as an external source of power. It is based on principles similar to those of the homopolar motor. The direct current produced is an effect of the homopolar nature of the design. Sometimes the name "homopolar generator" is reserved for this configuration. In this regard, see also homopolar generator. However, homopolar machines have not been practical for most applications.