NEW-INVENTED VARIOUS IMPROVEMENTS UPON SMOKE OR AIR JACKS
Year: 1806

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
PROSSER, of Back Hill, Hatton Garden, in the Parish of Saint Andrew,
in the County of Middlesex, Smith, do send greeting.
years
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirtieth day of October, in the forty-seventh year of His reign, did
give and grant unto me, the said John Prosser, my exors, adññors, and assigns,
His special licence, full power, sole privilege and authority, that I, the said
John Prosser, my exors, admors, and assigns, during the term of therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my "NEW-INVENTED
VARIOUS IMPROVEMENTS UPON SMOKE OR AIR JACKS;" in which Letters Patent
there is contained a proviso obliging me, the said John Prosser, under my
hand and seal, to cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, to be enrolled
in His Majesty's High Court of Chancery within one calendar month next
and immediately after the date of the said recited Letters Patent, as in and
by the same 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
Prosser, do hereby declare that my said Invention or New-invented Improve-
ments upon Smoke or Air Jacks is and are described in the above Drawings
and descriptions thereof, and that they are as follows (that is to say):-

page_text: The first improvement consists in making the box, case, or body of the singlo
smoke or air jack to extend the whole length from or near the center of the
inside of the chimney to the outside or breast thereof, and inclosing the spindle,
and terminating at or near the chain wheel, as reprosented by Figure the First.
The second improvement consists in raising the said spindle and chain wheel
in a slanting direction above the center of the worm, by which the oil flows
above the top carriage of the worm without the assistance of pipes or tubes,
the box, case, or body being one intire piece, except the top, which is screwed
or fastened on to remove at pleasure, continued from or near the center of the
flue to the outside of the breast of the chimney, by which the oil put in the
box, case, or body next the chain wheel runs round and incloses the whole
work, as contained in Figure the First.
The third improvement consists in making the chain wheel of brass or iron
instead of wood, and of placing in the groove or space in which the chain or
chains runs or run tags and holes, thereby effectually preventing the chain or
chains from slipping.
Figure the Second represents the two patterns or moulds from which the
improved chain wheel is çast, four of which, screwed together upon the
spindle, with a nut at the end of the spindle, forms a wheel for two chains.
Figure the Third is a representation of the contents or machinery as
intended for inclosure in Figure the First. B, the worm on which the fly A
acts, which fly may be made in the usual way, with, four, five, or six fans, and
the worm may be of a single or double thread; c, the top carriage in which
the worm runs; d, the bottom carriage and steel step; e, the plate in which
c and d are fixed; f, the steel step in which the pivett of the spindle of the
worm wheel runs; g, a scrow which fastens the plate e to the box, case, or
body; h, a steady pin at the bottom of plate e; 1, the worm wheel; K, K,
two friction wheels working in i, a small frame, which frame drops into the
improved box, case, or body at m; n, the chain wheel.
Figure the Fourth-The improved box, case, or body applied to a jack
which works both vertically and horizontally. This box or body may include
the whole work, except the chain wheel n, and the small wheel with its
spindle and universal joint O.
Both the foregoing boxes, cases, or bodies may be applied to each of the
single and double jacks in use by making them the size of the wheel, and
omitting the old frame and other superfluous parts, and working small wheel
O in the upper part of the bevil gear wheels, the tops of which are shown
at P.
Figure the Fifth represents the improved box, case, or body in a different

page_text: form and way, which I call the compound and skeleton air jack. I call it
compound because it contains various wheels, pinions, or cranks connected
with the first worm wheel or the axles thereof, and continued any length of
time, as the situation of the chimney, flue, or place in which it is intended to
be fixed may require. I call it skeleton because the body may be made nearly
as small as two inches wide by from four, eight, or twelve inches deep. I call
it an air jack, because, like the others, the air is more the first moving
power than the smoke. The fly in Figure the Fifth, as at A, Figure the
First, and may be made of any size according to the fluc. B, Figure the Fifth,
is the worm; C, the improved skeleton box. The advantages of this form
of the box are great, and are as follow:-Suppose the jack is fixed in a
very small flue, or in the funnel of a ship's stove; then, in the usual way,
the body of this old jack almost fills up the flue or funnel, crossing it, being
from nine to twelve inches wide in the box, and thereby preventing the
fly from being easily taken up and down, and greatly checking the draft,
whereas in this it is the reverse, the box, case, or body being made as narrow
as two inches, a trifle more or less, and continued on from or near the center
of the flue through the breast of the chimney to the outside in any direction cither
on the right or left side, or in the center of the fireplace, as the situation of the
chimney may require, and of any depth, from twelve inches, according as the
diameter of the wheels may require, and of any length according to the
optional number of wheels.. The advantages will further appear in a double
jack, which comes out in the center of the breast of the chimney, and
As in the old way three bevil gear
extends to the right and left hand.
wheels are required, but in this way one wheel only is fixed in the middle of
the spindle, as represented, Figure the Seventh, which runs to the right and
left in and with those of the narrow box, and will answer the end of the three
bevil gear wheels placed in the old way, and to each end of which may be
added a chain wheel, as at Figure the Fourth.
Figure the Sixth is a representation of the contents of Figure the Fifth. d, the
worm wheel on its short axis e, f, with the teeth cut the contrary way to the
last, and so on alternately to any length or number of wheels which the situation
or depth of the chimney may require on the axis of the last wheel G, on the
outside of the breast of the chimney; I place my chain wheel or wheels h, as
shewn in Figure the Fifth, on the axle, as shewn in the wheel G, Figure the
Sixth, which must be elevated above the line of the axis of the other wheels,
in order to admit the oil to rise and cover the top of the carriage of the worm.
I, the said top carriage of the worm; K, the lower carriage with the steel
step; L, the frame in which the whole wheels run, which frame drops

page_text: in at the top of the box or body e, Figure the Fifth; M, a notch on each
side of the box or body c to admit the axis of the last wheel G. When a
pinion is required on the axis or side of the first worm wheel d, for the
increase of power, the teeth of the following wheels may be cut straight.
All the boxes, cases, or bodies, except Figure the First, above described,
are shown with their tops uncovered, but each of them are supplied with plate
covers, and screwed down or fastened to the boxes, cases, or bodies by means
of screws screwed into the edge of the boxes, cases, or bodies, or other like
fastenings; and cach cover has a small hinge at or near the chain wheels on
the outside of the breast of the chimney, by which means oil or any substitute
for oil may be introduced, as occasion may require, without ascending the
chimney. These boxes, cases, or bodies, and covers, are made of cast iron or
any other metal, being first made in wood wider at the top than the bottom,
in order to give case to the founder in moulding. Where and when cast-iron
ones cannot be procured, then I make them of sheet iron or copper or other
proper metal.
In witness whereof, I, the said John Prosser, have hereunto set my
hand and seal, the Twenty-ninth day of November, in the year of
our Lord One thousand eight hundred and six.
AND BE IT REMEMBERED, that on the Twenty-ninth day of Novem-
ber, in the year of our Lord 1806, the aforesaid John Prosser came before
our said Lord the King in His Chancery, and acknowledged the Specifi-
cation aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stampt
according to the tenor of the Statute made for that purpose.
Inrolled the Twenty-ninth day of November, in the year of our Lord