The Sun.
London, England, 1848-02-03 00:00:00

HYDRAULIC TELEGRAPH.

We lately inspected a new species of telegraph,
produced from the action of water, patented by Mr.
Jowett, which appears to us very simple and ingenious,
and is likely to excite some attention, both from its
own merits and from the interest which is taken in
this means of communication at present. The idea of
using water as a medium by which to communicate
from place to place arose from its well-known incom-
pressibility, and we find Mr. Jowett quoting, in his
prospectus, from Dr. Lardner, the following passage,
which conveys the leading feature of his invention :
" A pressure excited on the liquid at one end of the
tube will be communicated to any surface in contact
with the liquid at the other end, whether the tube
between the two extremities be straight, curved, or
angular, or whether it pass upwards, downwards, or
in an oblique or horizontal direction. It may be
carried through the walls of a building, through the
course of a river, under, over, or around any obstruc-
tion or impediment, or, in fact, according to any course
or direction whatsoever.

"If a tube, filled with water, extended from
London to York, a pressure excited on the liquid at
the extremity in London would be instantaneously
transmitted to the extremity at York."
'There is, perhaps, a limit to this doctrine, where
curves and undulations are to be overcome, and also
from the cohesive power of the particles of water to
that with which they are in contact.
The model now exhibiting consists of a small tube
with a piston and indicator at each end. An up-
right plate contains the letters of the alphabet, the
first letter being at the top of the plate at one sta-
tion, and at the bottom of the plate at the other.
Thus, if a telegraph of this description were
laid down from London to York, the indicator, if
pointing to the letter A, would be at the top of
the plate at the former place, and at the bottom at
' the latter. As the one piston descends, the other,
from the pressure of the water, ascends in exact
proportion, each indicator pointing to the same
letter. In the model, as we hare stated, the plates
containing the letters are placed upright; but it will
be easily seen that a horizontal dial can also be used,
by means of a rack upon the piston and toothed
pinion to guide the indicating hand. This dial may
contain two or more circles, into which contracted
sentences on any number of subjects can be inserted,
the indicator being shortened so as to meet each
circle. If it were wanted to communicate any in-
telligence upon railways, as an example, suppose the
contracted sentences relating to this subject were in
the inner circle, the first intimation would be to
shorten the indicator, so that its point would ex-
actly touch the words which are to be commu-
nicated.
If a line of pipes were laid down from any given
distance, each intermediate station would be com-
municated with by means of branch pipes. To each
piston a bell is attached, and the first motion would
sound this, putting every one on the qui vice. If
the communication were intended for the first station,
the bell would strike one, and so on for the others.
Without passing any strong opinion as to the
its
merits of this invention, we must say that
ex-
treme simplicity struck us as an advantage of great
importance. The difficulties which may at first
sight strike the observer, such as gettingrew
toyer heights
above the level of the stations, a
con-
sideration it will be seen can be got
overa bylocalupon ap •
pliances. Perhaps the most serious would arise
fact that the pipes will require to be
placed from
under-
ground so far as to keep them from atmospheric in-
fluence, for in the event of any taking
breakage
it would be difficult indeed to tell the p
reciselocpaalite;
of the accident. In the case of wires as used at pre-
sent, any damage they may sustain is easily found
out, and can be as easily remedied ; but in the case
of underground pipes filled with water, unless, indeed,
this agent be in sufficient body to force itself to the
surface, we do not see how an accident can occur
without causing much labour and cost. The
inventor claims for his plan over the present electric
telegraph greater economy in construction to the
extent of two-thirds, no expense whatever after
the first outlay, and the impossibility of any,
physical impediment interfering with its work-
ing. Giving Mr. Jowett every credit for his inge-
nuity in bringing into practical operation a great
principle in natural philosophy, we must demur to
the conclusions he has come to. All things are liable
to destruction, and must be replaced ; height,
depth, sinuosity, and distance are impediments which,
even in the case of water, and notwithstanding its in-
elasticity, must be got over, and these cannot be ac-
complished without outlay. We admit, however, that
his plan would be less expensive in every way than
the electric telegraph, and is certainly not liable to
the objection that the agent used is apt to lose its
power, thus rendering constant superintendence ne-
cessary. The plan, whether generally adopted or
not, is certainly well worthy of consideration, and no
one can examine tse model without being struck
with the principle which it so beautifully illustrates.