98 
THE TELEGRAPH . 
arrivai of the train from London with our guests. Then the 
steam-boat with our friends and the telegraphic apparatus on 
board would come into the position shown on the right, to take 
up the end of the wire. But during the night the appearance 
of the weather had changed : the wind rose, and the sea 
became so rough, that not only would the experiment have been 
useless, but it would have been impossible to avoid breaking the 
wire. It. was therefore decided to join the upper wire of the over¬ 
ground line to the gutta-percha covered wire ; then, by sinking 
this last into the sea, to carry it round the pier and the light¬ 
house, and connect it with the telegraphic apparatus that was 
on board the steam-boat, moored alongside the pier, as shown 
in the figure. The conditions of experiment would thus be the 
same as if the steam-boat with the end of the wire had been 
in open sea, although the effect would be less striking. 
“ The operations took place on board without any previous 
trial, although there was great risk of the wire being broken by 
the waves dashing against the pier. Everything being ready, 
I seized the handle of the instrument and signalled the call to 
London (the letter L). 
“ I had an immediate answer to this signal. It was a 
quarter to one o’clock as my message passed under the waters 
of the Channel direct to London. These are the words : ‘ Mr. 
Walker to the Directors. I am on board of the Princess 
Clementine . I have succeeded.’ Other communications were 
exchanged, and after several hours’ immersion, the wire was 
taken up uninjured.” 
The same year Mr. Walker drew up a map of soundings in 
the Channel, showing the depths, and the track that would 
have to be followed in laying a telegraphic cable between France 
and England. This is nearly the direction taken by the pre¬ 
sent cable between Calais and Dover. 
It was reserved for Jacob and John W. Brett to practically 
realise on a great scale the project that had merely been con¬ 
ceived by others. As early as 1845, the Messrs. Brett took 
out a patent for their invention of a submarine cable, having 
the insulating material made of india-rubber and other sub¬ 
stances. Gutta-percha had not at that time come into use for 
telegraph lines. The insulating substance had to be protected 
