clock-work alarm, in which an electro-magnet attracted an armature of
soft iron, and thus withdrew a detent, allowing the works to strike the
alarm. This idea was suggested to him on March 17, 1836, while reading
Mrs. Mary Somerville's 'Connexion of the Physical Sciences,' in
travelling from Heidelberg to Frankfort.

Cooke arrived in London on April 22, and wrote a pamphlet setting forth
his plans for the establishment of an electric telegraph; but it was
never published. According to his own account he also gave considerable
attention to the escapement principle, or step by step movement,
afterwards perfected by Wheatstone. While busy in preparing his
apparatus for exhibition, part of which was made by a clock-maker
in Clerkenwell, he consulted Faraday about the construction of
electro-magnets, The philosopher saw his apparatus and expressed
his opinion that the 'principle was perfectly correct,' and that
the 'instrument appears perfectly adapted to its intended uses.'
Nevertheless he was not very sanguine of making it a commercial success.
'The electro-magnetic telegraph shall not ruin me,' he wrote to his
mother, 'but will hardly make my fortune.' He was desirous of taking
a partner in the work, and went to Liverpool in order to meet some
gentleman likely to forward his views, and endeavoured to get his
instrument adopted on the incline of the tunnel at Liverpool; but it
gave sixty signals, and was deemed too complicated by the directors.
Soon after his return to London, by the end of April, he had two simpler
instruments in working order. All these preparations had already cost
him nearly four hundred pounds.

On February 27, Cooke, being dissatisfied with an experiment on a mile
of wire, consulted Faraday and Dr. Roget as to the action of a current
on an electro-magnet in circuit with a long wire. Dr. Roget sent him
to Wheatstone, where to his dismay he learned that Wheatstone had been
employed for months on the construction of a telegraph for practical
purposes. The end of their conferences was that a partnership in
the undertaking was proposed by Cooke, and ultimately accepted by
Wheatstone. The latter had given Cooke fresh hopes of success when he
was worn and discouraged. 'In truth,' he wrote in a letter, after his
first interview with the Professor, 'I had given the telegraph up since
Thursday evening, and only sought proofs of my being right to do so ere
announcing it to you. This day's enquiries partly rev