AN IMPROVED METHOD OF CONSTRUCTING AND BUILDING LOCKS WITH AN INVERTED GROIN OR GOTHIC CONIC ARCH; ALSO AN IMPROVED FORM OF THE GATES, AND AN IMPROVED METHOD OF OPENING AND SHUTTING THE SAME
Year: 1810

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME.
WHEREAS by His Majesty's Royal Letters of Patent, bearing date at
Westminster, the Seventh day of September now last past, duly granted to
me, writing, that I, David Mathews, of Rotherithe, in the County of Surry,
Engineer, had represented that I had found out and invented "AN IMPROVED
METHOD OF CONSTRUCTING AND BUILDING LOCKS WITH AN INVERTED GROIN OR GOTHIC
CONIC ARCH; ALSO AN IMPROVED FORM OF THE GATES, AND AN IMPROVED METHOD OF
OPENING AND SHUTTING THE SAME;" and that the said David Mathews was the
first and true inventor thereof, and that he, the said David Matthews, had
humbly prayed that His Majesty would be graciously pleased to grant unto
him such Letters Patent for the sole use, benefit, and advantage of his said
Invention, within England, Wales, and Town of Berwick-upon-Tweed, for the
term of fourteen years, in pursuance of the Statute in such case made and
provided, His Majesty did thereby, subject to conditions and clauses and pro-
visoes therein contained, give and grant unto the said David Mathews,
his exors, adors, and assigns, His special licence, full power, sole privilege
and authority, that he, the said David Mathews, his exors, adññiors, and
assigns, and every of them, by himself and themselves, or his or their deputy
or deputies, servants or agents, or such others as the said David Mathews,
his exors, admiors, or assigns, should at any time agree with, and no others,

page_text: from time to time and at all times thereafter during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend the said
Invention within that part of our United Kingdom of Great Britain and
Ireland called England, our Dominion of Wales, and Town of Berwick-upon-
Tweed, in such manner as to him, the said David Mathews, his exors, admors,
or assigns, or any of them, should, in his or their discretions seem meet, and
that he, the said David Mathews, his exors, adññiors, and assigns, should and
Jawfully might have and enjoy the whole profit, benefit, commodity, and advan-
tage from time to time coming, growing, accruin, and arising by reason of
the same Invention, for and during the term of years therein mentioned, to
have, hold, exercise, and enjoy the said licence, powers, privileges, and
advantages therein-before granted, or mentioned to be granted, unto the said
David Mathews, his exors, adñiors, and assigns, for and during and unto the
full end and term of fourteen years from the date of these Presents next and
immediately ensuing, and fully to be compleat and ended according to the
Statute in that case made and provided; in which said Letters Patent is con-
tained, among other special provisoes, a proviso that if the said David Mathews
should not particularly describe and ascertain the nature of his said Invention,
and in what manner the same is to be performed, by an instrument in writing
under his hand and seal, and cause the same to be enrolled in the High Court
of Chancery within two calendar months next and immediately after the date
of those Letters Patent, that then these our Letters Patent, and all liberties
and advantages whatsoever thereby granted, shall entirely cease, determine,
and become void, anything herein-before contained to the contrary thereof in
anywise notwithstanding.
NOW KNOW YE, that I, the said David Mathews, in compliance with the
said proviso, do hereby declare that the nature, purpose, and object of my said
Invention hereinafter particularly described is, in the first place, to render the
construction of locks and lock gates less expensive than heretofore, to diminish
the pressure of the water upon the gates, to render the lock less liable to be
blown up, and to work the gates with less labor than hath heretofore. been
used, and I do also declare that my said Invention, and the manner in which
the same is to be performed, is particularly described and ascertained in and by
this instrument and the Drawing thereunto annexed, that is to say:-
The form of each of the lock gates, instead of being as usual square or
oblong, having the upper and lower edges parallel, will. be such that the depths
of the gates will encrease from the hanging post to the meeting post, making
the lower edge a straight line or a curve descending from the lower end of the

page_text: banging post to the lower end of the meeting post, as in Fig. 1, where A, B,
C, D, represents one of the lock gates; A, B, the hanging post, D, C, the
meeting post; B, b, C, the line formed 'by the lower edge of the gate; and
A, a, C; the line formed by the section of the body of the lock, parallel to the
gate; by this means the construction of the gate is less expensive, from its not
requiring to be equally strong and not taking so much timber; also the pres-
sure against the gate is much diniinished, on account of the surface exposed
to the fluid being less than hath heretofore been, and by that means the pres-
sure against the side walls is also less than in tlie case of the common lock
gate. The gates will shut against a sill in the form of the lower edge of the
gates, which sill will project a little way beyond 'the termination of the body
of the lock, so as to receive, with the hollow groins; the whole pressure of the
gates; the body of the lock will terminate on each side in a plain parallel,
or nearly so, to the gate on that side when shut, at a convenient distance from
the gate, as in Figure 2, where O, F, C, E, represents the termination of the
body of the lock parallel, or nearly so, to the gate M; P, G, A, D, the termi-
nation of the body of the lock parallel, or nearly so, to the gate N; K, I, is the
part of the sill projecting a little beyond the plane O, F, E, C, to receive the
pressure of the gate M; H, I, is the part of the sill projecting beyond the
plane P, G, A, D, to receive the pressure of the gate N, the front of the sill
is represented by the black line K; I, H; the two parts of the sill from a
groin arch. The lower edges of the gates, instead of running on a platform as
usually constructed, will move a little above a surface of brick or stone, which,
in form, has the figure which is swept out by the lower edges of the gates in
opening, but is placed a little below them.in Figure 1; if m, n; be a line a
little below the lower edge of the gate, and having exactly the same form, and
m, o, be the axis on which the gate: turris, produces the surfaces above men-
tioned, will be for the gate A; B, C, D, the surface traced out by the line mn;
if the plane m, n, o, revolve about nu, o, 'and' in the same way for the other
gate; if the lower edge of the gate be in a straight line, it will be a regular
conical surface; if curved line, it will be a curved conical surface; by this
means the body of the lock and the sill form an arch, terminating in the groin
arch, the strength of which is opposed to any effort of the water to blow up
the lock, and the construction of the conical or curved surfaces renders it
necessary to make a platform in the usual way, which is a considerable saving
of expence. Upon the above-mentioned surface a circular rib of iron is raised,
having the same centre with that on which the gate turns, on which rib the
gate will turn by means of a roller, the rib will be most conveniently placed
so as to be always under the centre of gravity of the gate, and motion will be

page_text: communicated to the gate by means of a pinion and rack segment, whose.
centre will also be the centre of the gate's motion, one end of the rack seg-
ment will be fastened to the back of the gate, the other end will run into the
wall by means of a culvert having a corresponding circular direction to meet
the pinion, which will be turned by a capstan; at the surface of the ground
the rack may be fastened to the bottom of the gate, and may be supported by
rollers running on the circular rib continued into the wall as far as is necessary,
or the rack may be fastened to the centre of the pressure of the gate, and
may be constructed of wood and iron, or iron cast hollow, so as to be as near-
as may be of the specific gravity of water. In Figure 3, A, B, represents a
section of the gate, at the place where the rack segment is fastened; C, D,
is the rack segment C fastened to the gate, and the end D running into the
culvert and meeting the pinion E, placed below the surface of the ground;.
A, B, F, represents the conical surface a little below the lower edge of the
gate; G, H, represents the other gate half open in Figure 4; A, B, C, D,
represents the culvert, running circularly into the recess wall in which the rack
segment moves; or A, B, C, D, will represent the same when the rack seg-
ment is applied higher up in the gate. Figure 5 represents the appearance at
the surface B, C; C, D, the gates shut; A and a, the shafts of the spindle
which connect the capstan and pinion. Figure 6 represents the capstan, drum-
head, bars, spindle, and pinion, G being the pinion; or the motion may be
communicated by substituting for the rack segment an iron segment of a
circle, with a chain tort, and passed once round a roller, which is in place of
the pinion C, ribbed vertically to create motion; this chain is to be sunk in
the outer edge of the iron segment, to prevent its assuming the form of a
straight line. In Figure 7, Part 1, A, B, represents a rib of the lock gate;
C, the place where the iron segment is fastened to the gate; C, F, E, the iron
segment; C, f, D, e, the chain running once round the roller D. In Figure 7,
Part 2, the capstan, spindle, and roller are represented; 9 is the roller, with
the chain passed once round it. By both these modes fewer hands will be
required to work the gates than according to the old method.
In witness whereof, I have hereunto set my hand and seal, this Seventh
day of November, in the year of our Lord One thousand eight hundred
and ton
Sealed and delivered in the presence of
W" GREGSON.
CHAB WYNNE.
DAVID (L.s.) MATHEWS.

page_text: AND BE IT REMEMBERED, that on the Seventh day of November,
in the year of our Lord 1810, the aforesaid David Mathews 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 Statutes made for that purpose.
Inrolled the Seventh day of November, in the year of our Lord One
thousand eight hundred and ten.