12 
Dr Colladon's Narrative of a Descent 
acquainted with the method they employed to make themselves 
understood. In going up, the sensations which we experienced 
in the head were very different from those which we felt in de- 
scending. It seemed to us that our heads were growing larger, 
and that all the bones were about to separate. This disagree- 
able sensation, however, did not last long ; we were in a short 
time above the surface, not only much pleased with what we 
had seen, but also with the idea of emerging safe from our nar- 
row prison. 
The signals made use of by the workmen are very simple : 
they consist in a smaller or greater number of strokes given with 
a hammer against the sides of the bell, according to the wishes 
of the workmen. These signals are easily heard on board, 
though no noise made above reaches the bell. 
We must remark, that there is a north and south end fixed 
to each bell, and which is always attended to by those on board, 
so that they can be moved with accuracy whenever they want to 
work, either south, north, west or east* 
The signals for the various operations are as follow : 
1, Stroke means more air, or pump strong, 
2 , Stand fast, which is applicable to all mo- 
tions. 
3, Hoist. 
4 , Lower. 
5, More south. 
6, North. 
7, Front. 
8, Back. 
9, Lower down the bucket. 
10, Hoist up the bucket loaded, 
and so on. 
The men also send up a note of what they want upon a label, 
which is instantly attended to if practicable, or some intimation 
sent down to them that it cannot be done. This is effected by 
means of a cord, one end of which is in the bell, and the other 
upon deck. 
It is by the signals above described that the bell is moved 
from one place to another in search of stones. This is effected 
by raising the bell a few feet from the bottom, and then, by the 
aid of the moorings of the ship, the bell sweeps along in any 
desired direction. As soon as a large stone is discovered, a sig- 
nal is made, the horizontal movement is stopped, and the bell 
lowered over the stone. If the bell be a little aside, the work- 
men can, by standing in the bottom of the sea, and pressing with 
their shoulders against the bell, make it swing a foot or two in 
