they have not got the stimulation before their eyes, of glory to be
gained. Personally I am of the opinion that the torpedo broke surface
because, being fired from the outside tubes, it probably started too
shallow, dived deep, recovered shallow and dived deep, broke surface
and dived very deep. A sticky motor or sluggish weight would give this
effect.

And are these external tubes water-tight? Theoretically, yes, but what
of practice? We have been down to forty metres several times during
this trip, and not once have we had a chance on the surface of getting
at the two external tubes; add to which our depth gear, with the pivots
of the weight exposed to water if the tube does flood and then you have
rust, corrosion and heaven knows what complications.

I saw a British Mark 11.50 torpedo at the torpedo shop at Bruges the
other day, and I was much struck with their deep depth gear, which is
of the unrestrained Uhlan type, i.e., weight and valve interdependent.
But then the main feature is that the whole gear is contained in a
separate water-tight chamber.

Our system is certainly a great saving in space, and is much neater in
design, whilst I prefer the Uhlan principle of valve conjuncting with
weight, but it would be interesting to know whether the British have
much trouble with the depth-keeping of their torpedo.

I have written quite a disquisition on depth gears; I must get on with
my record of events.

After lunch we had a good look round, but the small airship was still
hanging about, flying slowly in large circles.