Barlow's Wheel is the name given to an early demonstration of an electric motor, designed and built by English mathematician and physicist, Peter Barlow in 1822. An electric current passes through the hub of the wheel to a mercury contact on the rim; this is contained in a small trough through which the rim passes. Due to health and safety considerations brine is sometimes used today in place of mercury. The interaction of the current with the magnetic field of a U-magnet causes the wheel to rotate. The presence of serrations on the wheel is unnecessary and the apparatus will work with a round metal disk, usually made of copper. Electric motors of various sizes. ... Royal motto (French): Dieu et mon droit (Translated: God and my right) Englands location within the British Isles Official language English de facto Capital London de facto Largest city London Area – Total Ranked 1st UK 130,395 km² Population – Total (mid-2004) – Total (2001 Census) – Density Ranked 1st UK... Mathematics is often defined as the study of topics such as quantity, structure, space, and change. ... A black hole concept drawing by NASA. Physics (from the Greek, φυσικός (physikos), natural, and φύσις (physis), nature) is the science of the natural world dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces. ... Peter Barlow Peter Barlow (1776 - March 1, 1862) was an English writer on pure and applied mathematics. ... 1822 was a common year starting on Tuesday (see link for calendar). ... In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ... Brine is water saturated or nearly saturated with salt. ... Current flowing through a wire produces a magnetic field (M) around the wire. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ...

"The points of the wheel, R, dip into mercury contained in a groove hollowed in the stand. A more rapid revolution will be obtained if a small electro-magnet be substituted for a steel magnet, as is shown in the cut. The electro-magnet is fixed to the stand, and included in the circuit with the spur-wheel, so that the current flows through them in succession. Hence the direction of the rotation will not be changed by reversing that of the current; since the polarity of the electromagnet will also be reversed."

(Excerpt taken from the 1842 edition of the Manual of Magnetism, page 94) 1842 was a common year starting on Saturday (see link for calendar). ...