intelligent countenance, was full of
animation. Sir Henry Taylor tells us that he once observed Wheatstone at
an evening party in Oxford earnestly holding forth to Lord Palmerston
on the capabilities of his telegraph. 'You don't say so!' exclaimed the
statesman. 'I must get you to tell that to the Lord Chancellor.' And so
saying, he fastened the electrician on Lord Westbury, and effected his
escape. A reminiscence of this interview may have prompted Palmerston
to remark that a time was coming when a minister might be asked in
Parliament if war had broken out in India, and would reply, 'Wait a
minute; I'll just telegraph to the Governor-General, and let you know.'

At Christchurch, Marylebone, on February 12, 1847, Wheatstone was
married. His wife was the daughter of a Taunton tradesman, and of
handsome appearance. She died in 1866, leaving a family of five young
children to his care. His domestic life was quiet and uneventful.

One of Wheatstone's most ingenious devices was the 'Polar clock,'
exhibited at the meeting of the British Association in 1848. It is based
on the fact discovered by Sir David Brewster, that the light of the sky
is polarised in a plane at an angle of ninety degrees from the position
of the sun. It follows that by discovering that plane of polarisation,
and measuring its azimuth with respect to the north, the position of the
sun, although beneath the horizon, could be determined, and the apparent
solar time obtained. The clock consisted of a spy-glass, having a nichol
or double-image prism for an eye-piece, and a thin plate of selenite for
an object-glass. When the tube was directed to the North Pole--that
is, parallel to the earth's axis--and the prism of the eye-piece turned
until no colour was seen, the angle of turning, as shown by an index
moving with the prism over a graduated limb, gave the hour of day. The
device is of little service in a country where watches are reliable; but
it formed part of the equipment of the North Polar expedition commanded
by Captain Nares. Wheatstone's remarkable ingenuity was displayed in the
invention of cyphers which have never been unravelled, and interpreting
cypher manuscripts in the British Museum which had defied the experts.
He devised a cryptograph or machine for turning a message into
cypher which could only be interpreted by putting the cypher into a
corresponding machine adjusted to reproduce it.

The rapid development of the telegraph in Europe may