CERTAIN IMPROVEMENTS IN RAILWAY, STEAMBOAT, AND OTHER SIGNALS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
DOULL, of Euston Grove, in the County of Middlesex, Civil Engineer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing dats at Westminster, the Eighth day of February,
One thousand eight hundred and forty-seven, in the tenth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Alex-
ander Doull, my exors, adñiors, and assigns, Her especial licence, full power, sole
privilege and authority, that I, the said Alexander Doull, my exors, admors,
or assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein expressed, should and law-
fully might make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, and in the Islands of Guernsey, Jersey,
Alderney, Sark, and Man, and also in all Her said Majesty's Colonies and
Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS IN RAILWAY,
STEAMBOAT, AND OTHER SIGNALS;" in which said Letters Patent is contained a
proviso that I, the said Alexander Doull, should cause a particular description
of the nature of my said Invention, and in what manner the same is to be.
performed, by an instrument in writing under my hand and seal, to be inrolled
in Her said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Alexander Doull, hereby declare that the nature of my said Invention con-

page_text: sists in the employment of a compressed atmospheric air apparatus for pro-
ducing audible railway, steamboat, and other signals, in a similar or a
somewhat similar manner to that in which sounds are now ordinarily produced
by the steam whistle of locomotive engines; and also in a mode or modes of
varying the sound, and producing several distinct sounds, by rapidly opening
and shutting the communication between the reservoir of the compressed air
and the whistle; and, further, in a mode or modes of combining two or more
whistles of dissimilar sounds so as to produce an extended scale of distinct
signals. And I declare that the manner in which the said Invention is carried
into effect is fully set forth in the following description thereof, reference being
had to the Drawings hereunto annexed: —
The vessel or receiver into which the atmospheric air is compressed may be
of any convenient size, and composed of any material capable of being made
air-tight and sustaining the necessary pressure; and it may also have any
convenient shape given to it, as cylindrical with flat or hemispherical ends,
or square, or rectangular. The atmospheric air is to be condensed into the
receiver by an air pump or air pumps, single or double acting, as may be
found most suitable in practice. The air pumps may be worked by hand or
by any other convenient means. When the apparatus is applied to a railway
train, and placed in charge of the guard of the train, or of a person appointed
expressly to attend to it, motion may be communicated to the
pumps from any
moving part of the carriage by cranks and connecting rods, or by excentric
wheels, or by bands, or by a combination of these several modes. Or, when
the apparatus is employed in a steamboat, power may be obtained in like
manner from the moving parts of the steam engine or machinery in motion
connected therewith for driving the air pumps. It will, however, be neces-
sary in all cases, whatever may be the mode adopted of connecting the moving
parts of any machinery with the air pump or pumps of the compressed air
apparatus, that the connections shall be such as can be readily thrown off
or disengaged, and recourse be had to manuel labour, as in the case, for
example, of the stoppage of a railway train or of a steamboat. When the
atmospheric air signal apparatus is attached to any moving machinery, as a
railway train or a steam engine, it will be necessary to have a safety valve
connected with the compressed air vessel, and to keep it loaded to bear such
maximum pressure as may be necessary for the efficient sounding of the
whistle.
Figures 1, 2, and 3, Sheet I. of the annexed Drawings, represents one
mode in which my compressed air signal apparatus may be constructed and
worked. A is the receiver or vessel into which the atmospheric air is to be

page_text: compressed by the air pump b, which is here supposed to be single-acting;
c is a valve through which the condensed air passes from the air pump, along
the tube d, to the air vessel A; e is the connecting rod between the piston of
the air pump and the crank f. Motion is given to the crank by the handle,
9.
h, h, are guide rods passing through the stays i, i, attached to the cylinder of
the air pump; k is a whistle, similar to those which are at present attached
to locomotive engines, and sounded by steam from the boiler. The shape of
the whistle may, however, be varied, as herein-after explained, so as to produce
distinct and dissimilar sounds. L is a toothed wheel working into the pinion m;
o is a triangular support or bracket to which the wheel L is attached, and
upon which it revolves. This bracket is firmly connected to the top of the air
vessel A. n is a handle by which the wheel L is put in motion; p is a cock
or valve behind the pinion, by means of which the compressed air is made to
pass from the receiver A, through the pipe r, to the whistle k. The pinion m
is attached to this cock, and when the wheel L is revolved rapidly a thrilling
sound is produced, which may be so varied and combined with other sounds
as to form a gamut of considerable range, which may be still farther extended
by a combination of two whistles of dissimilar sound, connected by wheel-work
or otherwise, as herein-after explained.
The Drawings on Sheet II. represent an apparatus with two air pumps and
two whistles combined. Figure 1 is a front elevation of the entire apparatus;
Figure 2 is a front view of the whistles, wheel pinions, &c. on an enlarged
scale; and Figure 3 is a side elevation of the parts shewn in Figure 2 on the
same scale. A is a cylindrical air-tight vessel or receiver, with hemispherical
ends; B, B, are air pumps partly let into the cylinder. The valves at the
bottom of the pumps open directly into the air receiver. C, C, are standards
or brackets to support the crank shaft; D, D, piston rods; E, crank shaft;
F, handle by which motion is given to the crank shaft, and consequently to
the air pumps; G is a drum over which a band may be passed to obtain
motion from any moving machinery; H, H, whistles connected with the
compressed air receiver; L, toothed wheel to give motion to the two
pinions J, J, which are attached to the whistle. These pinions are placed
upon, or rather form, the handles of the cocks which admit the compressed
air to the whistle from the receiver, and they are so constructed that they can
be moved away from the toothed wheel L, as shewn at K, Figure 8. By the
motion of the wheel L, when the two pinions are in connection therewith, a
thrilling sound is produced by both whistles. The pinions may, however, be
alternately withdrawn, and the whistle connected with the withdrawn pinion
be made to sound steadily, or not to sound at all, while the whistle in con-

page_text: nection with the toothed wheel is made to produce a thrilling sound; and, in
the same way, a great many other peculiar combinations of sound may be
produced.
Having now described the nature of my said Invention, and the manner in
which the same is to be performed, I desire that it may be distinctly under-
stood that I do not confine myself to the details which have been herein set
forth and described, inasmuch as they may be greatly varied and modified
without departing materially or essentially from my said Invention in any of
its distinguishing features, and that what I claim is as follows:-
First, I claim the employment of compressed atmospheric air for tho
production of audible railway, steamboat, and other signals, as before
exemplified and described.
Second, I claim the mode of varying the sound, and of producing soveral
distinct sounds by rapidly opening and shutting the communication between
the compressed air receiver and the whistle, as before described.
Third, I claim the mode or modes of combining two or more whistles of
dissimilar sounds so as to produce an extended scale or gamut of distinct
signals, as before described.
And, fourth, I claim the application of the wheel-work, as before described,
to steam whistles of the ordinary construction, for the purpose of varying the
sounds obtained therefrom.
In witness whereof, I, the said Alexander Doull, have hereunto set my
hand and seal, this Soventh day of August, in the year of our Lord
One thousand eight hundred and forty-seven.
ALEXANDER (L.S.) DOULL.
AND BE IT REMEMBERED, that on the Seventh day of August, in the
year of our Lord 1847, the aforesaid Alexander Doull came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpo-c.
Enrolled the Seventh day of August, in the year of our Lord One thou-
sand eight hundred and forty-seven.