To the diver, however, save for the cascade of air through his air-pipe, the sea is silent.
An elbow tube is securely fitted on the helmet, to which is fixed an inlet valve, to which the air-pipe is attached.
The inlet valve is made that the air can enter, but in case of a break in the air-pipe it cannot escape.
One pull on the air-pipe signifies that the diver wants more air.
My communication-cord and my air-pipe led up between the barrels, to outer safety; but what of that?
The Soudan is joined to Egypt by the Nile, as a diver is connected with the surface by his air-pipe.
This is shown in detail in fig. 25, in which N is the brass ferule and M the rubber stopper through which the air-pipe passes.
To the air-pipe just before it entered the calorimeter was attached a copper can with a rubber diaphragm top.
Generally the air-pipe terminates either in the hollowed portion of the frame, or in an independent pot, or air chest.
In another moment the life-line and air-pipe ceased to run out, and then the assistant gave one pull on the line.