13 
of Edinburgh, Session 1875-76. 
soon thereafter were employed to establish electric telegraphs on 
most of the great English railways. 
In 1837 the five-needle telegraph was invented; in 1840, the 
alphabet dial telegraph; in 1841, the type-printing telegraph; and 
the automatic telegraph between 1858 and 1867. By this last 
machine it was found possible to transmit words at the rate of 
from 100 to 160 words per minute. 
In 1840 Wheatstone conceived the idea of a submarine telegraph 
cable, and pointed out both the difficulties and the means of 
obviating them. 
His last work was to contrive a new recording instrument for 
submarine cables, formed by a globule of mercury moving to and 
fro in a capillary tube containing acid, or by a drop of acid in a 
tube containing mercury, and which was found to be 58 times more 
sensitive than any recorder previously employed. He had gone to 
Paris to exhibit this invention to his colleagues of the Academy of 
Science, when he was attacked by the fatal illness — bronchitis— 
which terminated in his death. 
This brief notice of Wheatstone’s discoveries in the science of 
sound, optics, and electricity gives but a poor idea of the immense 
amount of brain work which he went through in the long life 
accorded to him. The papers which he contributed to Societies 
both in Great Britain and on the Continent are very numerous. 
They were always characterised by great lucidity of style and by 
copious and telling illustrations, which made them both attractive 
and instructive. 
Wheatstone was elected a Fellow of the London Royal Society 
in 1836, a Chevalier of the Legion of Honour in 1855, a Foreign 
Member of the French Institute in 1873. In 1868 the Govern- 
ment of Lord Derby conferred on him a knighthood. 
In private life Sir Charles Wheatstone had 'the reputation of 
being reticent and unsociable. The fact probably was, that his 
mind was constantly absorbed with the problems which were con- 
stantly presented to it. He was so nervous and bashful, that 
though always ready and pleased to describe his discoveries to any 
single individual, he entirely broke down when he attempted to 
address an audience. Hence, his Professorship of Natural Philo- 
