A CERTAIN INSTRUMENT OR TOOL, CALLED A DEEPENING TOOL, ON ANY PRINCIPLES OR CONSTRUCTIONS WHATSOEVER THAT DEEPEN WHEELS BY MEA- SURING OR GAUGING THEM
Year: 1767

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DOWNES, of the Parish of Saint Leonard, Shoreditch, in County of Middlesex,
Watchmaker, send greeting.
WHEREAS His present Majesty, by His Royal Letters Patent, bearing
date at Westminster, on or about the Thirteenth day of March last, in the
seventh year of His reign, was graciously pleased to grant unto me, my execu
tors, administrators, and assigns, licence for the sole making, using, exercising,
and vending "A CERTAIN INSTRUMENT OR TOOL, CALLED A DEEPENING TOOL, ON
ANY PRINCIPLES OR CONSTRUCTIONS WHATSOEVER THAT DEEPEN WHEELS BY MEA-
SURING OR GAUGING THEM," within that part of His Majesty's Kingdom of
Great Britain called England, His Dominion of Wales, and Town of Berwick-
upon-Tweed, for the term of fourteen years.
NOW KNOW YE, that I, the said John Downes, in compliance with and
performance of a provisoe or condition in such Letters Patent contained, do
hereby describe and ascertain the nature of my said Invention, and in what
manner the same is to be performed (which said tool is delineated in the
margin of this instrument), in manner following (that is to say):
This tool is a kind of proportional compass, adapted to that one purpose of
deepening wheels in clock and watch work. It has its joint at A, one end
from which is two inches and a half; the other five inches distant. To find
the place in the line A, B, of measuring the wheel, divide the line in propor-

page_text: tion to the primitive wheel and pinion, and add to this the tops of the teeth;
then at the tips or points of the teeth so added is the place of measurement
for a wheel of that number, whatever it be; and a narrow piece of brass being
fixed from B to E, as an index, the spiral wheel D is divided and numbred
from the said places of measurement, according to the number of teeth, from
twenty-four to one hundred; and will always, therefore, shew such place of
measurement in the line A, B, when the number is brought to the edge C; so
in the Drawing the tool will measure a wheel of sixty-two teeth; but if fifty-
four, or forty-eight, or any other number were required, turn the said spiral
upon the joint E till that number comes to the edge C, and it is done; you
then take the diameter of the wheel, or, in other words, measure or gauge
the diameter from C to F, resting the wheel against the spiral as at C;
this done, the distance G, II, at the other end is the distance of the centers;
or, in other words, will mark off the true distance of the pivot holes, so that
the wheel and pinion will be of a right depth in each other.
And I, the said John Downes, do further declare that I have in the
Drawing only made one line, divided and numbred for a pinion of six, but in
the tool there are four lines, divided and numbred for the four sorts of pinions
in common use, (viz³), six, eight, ten, twelve, and they are all made by the
aforesaid principle.
And I, the said John Downes, do hereby further declare that I have also
invented another tool or instrum for deepening clock and watch wheels, by
measuring or gauging them, which I have also delineated in the margin hereof,
and which answers the like purposes of deepening wheels by measuring or
gauging them, as the tool herein-before described; but the construction and
principles thereof are very different. And I do hereby describe and ascertain
the nature and use of my said last-mentioned tool or Invention, in manner
following (that is to say):-
This consists of three plates, lying one upon another; they move upon one
joint at II, and open and close at the other end (viz¹), at C, D, and E, by means
of the screw L and the slide M; this whole part will also open and close with
the part A, which is immoveable. There are four notches, each of sixty-seven
degrees, in this tool; A and B for the wheel; C and D for the pinion, and these
are five inches distance from II. Now, if you take such a wheel and pinion,
that when the wheel and pinion are put into the notches they (the notches)
may exactly reach down to the primitive wheel and pinion, it is plain if
you put the two opposite teeth of the wheel into the notches A and B that
you open A, B, to the primitive wheel; and if, by means of gauging the teeth,
you open E, D. by the screw L. to twice the primitive pinion, it will follow

page_text: that by putting the pinion in like manner into the notches C, D, you will
deduct once the primitive pinion, and thereby leave the diameter of the primi-
tive wheel and primitive pinion, which is the thing desired; for being the whole
diameter of the primitive wheel and pinion distant at the end, in the middle,
viz., at K the tool will measure off the half diameter of both; or, in other
words, the distance of the pivot holes; and by duly considering this theory it
will be plain that what will do in one instance will do in all the variety that
can happen. The method of opening E, D, to twice the primitive pinion is
by gauging one leaf at F, and the outside of two spaces of the wheel at G, if it
is a pinion of six; of three spaces if a pinion of nine; of four spaces if a pinion
of twelve;
and the rest in proportion: the two little gage points at G are fixed,
the one in the plate marked D, and the other in the plate marked E, at about
the one-eighth part of an inch, more than half way from H; the extremes at
F are the same distance from N as the gage points at G, and the whole piece
F, G, N, moves upon the center N; and forasmuch as for a pinion of eight,
you are to measure at G three spaces all but one third; and for a pinion of
ten, three spaces and one third; and as one third is just one eighth of the way
which the screw has opened the tool, therefore the round piece of brass at
O is marked with a spiral line, and an index pointing to it; and the spiral
is so divided, as by means of the index, it will in any part of it sett off' one
eighth of the opening to be added or substracted, as the pinion requires.
And I do hereby further declare that the hole at K, and the immoveable
part at A, in the last-described tool or instrument, are in their present form
fitted and intended for the purpose of joining thereto a certain other tool, but
not of my Invention, used for other purposes in the business of a watchmaker,
called an upright tool. And 1, the said John Downes, do hereby averr and
affirm, that the particulars above set forth, together with the shape, form, and
parts of the said two several tools or instruments so delineated in the said
margin, do contain a full, true, and perfect description of the use, nature, opera-
tion, and effect of my said Invention.
In witness whereof, I have hereunto set my hand and seal, this Second
day of July, in the year of our Lord One thousand seven hundred and

page_text: AND BE IT REMEMBRED, that on the day and year last above men-
tioned the aforesaid John Downes came before our said Lord the King in
His Chancery, and acknowledged the Specification 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.
in the sixth year of the reign of the late King and Queen William and Mary
and so forth
Inrolled the Sixth day of July, in the year above written.