On November 26, 1840, he exhibited his electro-magnetic clock in the
library of the Royal Society, and propounded a plan for distributing the
correct time from a standard clock to a number of local timepieces. The
circuits of these were to be electrified by a key or contact-maker
actuated by the arbour of the standard, and their hands corrected by
electro-magnetism. The following January Alexander Bain took out a
patent for an electro-magnetic clock, and he subsequently charged
Wheatstone with appropriating his ideas. It appears that Bain worked as
a mechanist to Wheatstone from August to December, 1840, and he asserted
that he had communicated the idea of an electric clock to Wheatstone
during that period; but Wheatstone maintained that he had experimented
in that direction during May. Bain further accused Wheatstone of
stealing his idea of the electro-magnetic printing telegraph; but
Wheatstone showed that the instrument was only a modification of his own
electro-magnetic telegraph.

In 1843 Wheatstone communicated an important paper to the Royal Society,
entitled 'An Account of Several New Processes for Determining the
Constants of a Voltaic Circuit.' It contained an exposition of the well-
known balance for measuring the electrical resistance of a conductor,
which still goes by the name of Wheatstone's Bridge or balance, although
it was first devised by Mr. S. W. Christie, of the Royal Military
Academy, Woolwich, who published it in the PHILOSOPHICAL TRANSACTIONS
for 1833. The method was neglected until Wheatstone brought it into
notice. His paper abounds with simple and practical formula: for the
calculation of currents and resistances by the law of Ohm. He
introduced a unit of resistance, namely, a foot of copper wire weighing
one hundred grains, and showed how it might be applied to measure the
length of wire by its resistance. He was awarded a medal for his paper