JF Ptak Science Books   Quick Post

Here’s an interesting combination of sweat and electricity–an enormous electrical device that was on display in an exhibit of “natural magic” at the Colosseum in Regent’s Park in 1839.  The large disk that the two guys are turning is actually larger in real life, being 7′ in diameter, the conductor being varnished copper, and the conducting balls being gilded–it must have been a very shiny experience, especially when they generated their electric spark.  In 1839 this was the largest electrical generating device in the world.  (I have a tiny version of that device here, something made out of old records coated with copper and found ball glasses acting as Leyden jars, all painted and varnished, the work of an 8 year old in 1925 who went on to a career in astronomy and became the most celebrated eclipse follower in the mid 20th century.)

This monster is made just 39 years after Volta’s first battery was made,  and not long after Oersted generated the first magnetic field from an electric current in 1820, the same year as Ampere’s solenoid. There were many quick and brilliant development from then to 1839 (also the year in which Daguerre perfected his collaborative work with Niepce to produce the photographic camera), not the least of which was the  Davidson’s creation of the first electric motor car/land locomotive, again in that same full year of 1839: