NEW INVENTED MACHINE, CALLED A FIRE ALARM
Year: 1763

page_text: GREEN, of Saint Martin's Court, London, Watchmaker. send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Royal Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-ninth day of July, in the third year of His reign.
give and grant unto me, the said John Green, my executors, adiñiors, and
assigns, and every of them, by myself and themselves, or by my and their
deputys, servants, and agents, or such others as I, the said John Green, my
executors, aduiors, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term of fourteen years
therein mentioned, II is especial licence, full power, sole privilege and authority,
that I, the said John Green, my executors, adiñiors, and assigns, should and
lawfully might make use, exercise, and vend, within that part of His Majesty's
Kingdom of Great Britain called England, His Dominion of Wales, and
Town of Berwick-upon-Tweed, my "NEW INVENTED MACHINE, CALLED A FIRE
ALARM," (which will infallibly alarm the sleeping persons before a fire can
have arisen to any dangerous height in any, even the most remote, part of the
house, and that upon any persons inspecting the face of the said machine
they will be informed in what particular floor or room in the house such fire is
then burning,) in such manner as to me, the said John Green, my executors,
adiors, and assigns, or any of them, should seem meet; in which said Letters
Patent there is contained a proviso, obliging me, the said John Green, to

page_text: cause a particular description of the nature of my said Invention, and in what
manner the same is performed, under my hand and seal, to be inrolled
in the ligh Court of Chancery within four kalendar months from the date of
the said Letters Patent, as in and by the said Letters Patent (relation being
thereunto had), may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Green, do hereby describe and ascertain the nature of my said new
änvented machine, called a fire alarm, and the manner in which the same
is performed, as follows, viz:-The machine consists of a frame screwed
against the side of the case; in which frame runs on the pivotts a barrell and
great wheel, with its click and spring; to which barrell hangs by a pulley the
main weight, the said weight to be wound up to the barrell by a winch on the
outside the case; by means of the falling weight, the great wheel acts on a
pinion, on whose arbor is rivetted a ballance or crown wheel, whose teeth, by
alternately striking the pallets of a verge, on the top of which is a hammer,
forces the said hammer to strike a bell; a click catching a pin in the crown
wheel keeps the main weight suspended; to the counterpoise of which click
is rivetted a long steel arm, which arm runs along the wheel front of the
machine, two or three inches behind the front plate, the front plate having
holes in it equal to your number of rooms or notices. In the space between the
plate and the steel arm are suspended a number of weights, fronted with brass
or other matter, on which are engraven the names of your rooms or doors, &c.,
and so situated, that when the weight shall have fallen to its lowest place
the engraving may appear through the hole in the plate. Immediately above
these weights are a row of pulleys, of equal number, as also another row on
the back of the case, for the gutt or chain (by which the weights are sus-
pended) to pass over to reach the first crank immediately over the machine.
In the back of each weight is fastened a hook, which extends over the click
arm aforesaid, and in its fall discharges the point of the click from the crown
wheel, and thereby causes a continued alarm, as its weight hinders the click
arm from rising again; from each weight the communication is carried by
chain or gutt to the first crank, and from thence by the nearest ways by
cranks and iron and brass wires to that room to which they respectively
belong. On entring which rooms, a cord is fastened to the wire, and carried
round the said rooms by pulleys, &c. under the cornice, and, if desired, also
under the surbase; to the other end of which cord is suspended a weight,
sufficient to keep the weight in the machine in a state of suspension, and also
to draw the cord so tight, that by its stretching or contracting by weather it
may raise or let fall that weight, and not the weight in the machine. The con-

page_text: sequence of all this is obvious: so soon as a fire in any room shall burn so high
as the ceiling it must inevitably burn the line, and the weight in the machine,
having nothing to keep it suspended, will fall, till the engraving is visible
through the hole in the plate, in its way taking (by means of the hook) the
click arm along with it, and thereby discharging the main weight and causing
the alarm, which will not cease till the main weight reaches the ground.
Those who chuse it may have a small alarm in any or every room, with the
weight laying over it, in manner of a draw clock, so the fire in that room will
at once discharge both alarms. There is an iron barr runs between the small
weights and the click arm, to hinder the weights from laying against the said
arm, and also to hinder the said weights (by means of stops) from falling too
low; and in such cases, where the weights in the machine may not be sufficient
to overcome the friction, there must be other weights so hung by cranks as to
assist them. In any case where weights have been mentioned, springs may
be used to the same purpose.
In witness whereof, I, the said John Green, have to this present Instru-
ment of Specification sett my hand and seal, this Twenty-fourth day of
November, in the fourth year of the reign of His said Majesty King
George the Third, and in the year of our Lord One thousand seven