A CERTAIN INSTRUMENT FOR THE PURPOSE OF ASSISTING THE, HUMAN BODY IN WALKING (AND WHICH I CALL AN ARTIFICIAL LEG) AFTER THE: Loss OF THE NATURAL LEG BY AMPUTATION OR OTHERWISE, UPON PRINCIPLES PAR SUPERIOR TO ANY OTHER INSTRUMENT OF THE KIND, BOTH FOR USE AND ORNAMENT, BEING CAPABLE OF PERFORMING ALL THE ACTIONS OF A NATURAL LIMB IN ALL ITS JOINTS,NAMELY, KNEE, ANCLE, AND TOES, AS WELL IN WALKING AS IN SITTING DOWN AND RISING UP, WITH GREATEST EASE AND SAFETY TO THE WEARER, AND OF. BEING APPLIED BOTH TO ABOVE AND BELOW THE KNEE
Year: 1790

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
MANN, of Bradford, in the County of York, Linen Draper and Mercer, send
greeting.
WHEREAS His most Gracious Majesty, by his Royal Letters Patent,,
bearing date at Westminster, the Twentieth day of January, in the thirtieth
year of the reign of His said Majesty, did give and grant unto me, the said
Thomas Mann, my executors, administrators, and assigns, His especial licence,..
full power, sole priviledge and authority, to make, use, exercise, and vend,
within the Kingdom of England, the Dominion of Wales, and the Town:
of Berwick-upon-Tweed, and also in all His said Majesty's Colonies and
Plantations abroad, "A CERTAIN INSTRUMENT FOR THE PURPOSE OF ASSISTING THE,
HUMAN BODY IN WALKING (AND WHICH I CALL AN ARTIFICIAL LEG) AFTER THE:
Loss OF THE NATURAL LEG BY AMPUTATION OR OTHERWISE, UPON PRINCIPLES PAR
SUPERIOR TO ANY OTHER INSTRUMENT OF THE KIND, BOTH FOR USE AND ORNAMENT,
BEING CAPABLE OF PERFORMING ALL THE ACTIONS OF A NATURAL LIMB IN ALL ITS
JOINTS, NAMELY, KNEE, ANCLE, AND TOES, AS WELL IN WALKING AS IN SITTING
DOWN AND RISING UP, WITH GREATEST EASE AND SAFETY TO THE WEARER, AND OF.
BEING APPLIED BOTH TO ABOVE AND BELOW THE KNEE," for the term of fourteen
years from the date thereof, and under and subject to the several provisions,.
clauses, conditions, and restrictions therein contained, as by the same appears;.
and in which said Letters Patent is also contained a proviso, obliging me,. the.
said Thomas Mann, under my hand and seal, to cause a particular description.

page_text: and specification of the nature of my said Invention, and in what manner it is
to be executed, to be inrolled in the High Court of Chancery within one
calendar month from the date of the said Letters Patent.
NOW KNOW YE, therefore, that I, the said Thomas Mann, in compliance
with the said provisoe, do, by this instrument in writing, under my hand and
seal, particularly, accurately, and correctly describe, ascertain, and specify the
nature of my said Invention, and the manner in which the same is to be
executed and performed, and do declare the annext plan to be a true repre-
sentation and description of the several joints and component parts of the said
instrument, and the references hereafter following to be true, correct, and
according to the said annext plan, that is to say:
Figure 1 represents the complete limb as it appears when the covering of
shammoy leather is taken off. A, B, C, rings fixt to the socket, to which elastic
straps are fastened, which go over the shoulders and fix the leg to the body;
D, E, pieces of leather by which the thigh is slung to the socket, and prevent its
rising off the lock too far; F, a brass or iron hoop, which goes round the thigh,
and keeps the slides from working loose in the groove; G, one of the
slides, which are fastened to the sockett; these are either made of the same
piece of wood as the sockett or distinct, and firmly secured to it by a thin
plate, as in No. 9; H, spiral springs, which give motion to the leg after
exercion of the thigh, are made of twisted wire, fastened above to the sockett
(in which and the thigh part is a small groove to receive them), and below to a
piece of leather joined to the patella; these are covered, as in No. 10, with
a plate of tin or brass to defend them, and render the surface equal; K, the
end of a steel pin, which goes through the slides, called the locking pin,
see No. 2; L, a repelling spring, fixed in the end of each slide, which
forces the sockett upwards, and loosens the lock when the pressure is taken
off; M, the center of the knee joint, through which runs an iron or steel pin b,
about half an inch thick, which is hollow; by means of a square on one end,
and a screw nutt on the other, it is made fast to the thigh part; the hole in
the leg is lined with leather, and polished with black lead dust. N, the pattella,
made in the natural shape of wood or stiff leather, rivetted to a piece of tough
leather, the lower end of which is fastened to the leg, the upper to the spiral
springs; it slides (when the leg moves) in a groove made in the thigh, and
renders the knee shapely in all positions. P, a spring of twisted wire, which
forces the steel down; it is kept in its place by means of a wooden or bone
pin d, which slides through the middle of it into a hole bored in the hind part
of the leg at the other end of the pin is a small half ball, against which the
end of the spring forces, and keeps it down in a small sockett made in the

page_text: heel of the foot, and by that means forces the foot up. Q, a spring fixt to the
oot and leg, which helps the former to hold up the foot when taken from
the ground; grooves are made in the hind and fore part of the wood to
receive those springs. R, the centre of the ancle joint, formed like the knee,
with the same kind of pin; the toe is the same, but the pin is too small to be
made hollow. S, three spiral springs, which act inside of the foot, and keep
the toes up when there is no pressure on them, see No. 7, where they are
fastened to three tough springs at one end, which go over the circular part,
about half the breadth of the toes, in three nicks, like pullies, and are fixed to
the toes; the springs are fastened at their other end by hooks in a cavity
of the foot, No. 6. The manner these springs are counteracted by pressure
is best explained by two sides views of the toe part f and g; when
pressure is taken off, a square end, the same breadth as the circular
part, will appear below the sole of the foot, as is represented by f, by the
end under the line, and the toes will be kept up; this end, when the pressure
comes upon it, will be forced into a cavity in the sole of the foot, as repre-
sented in g, when the end is even with the line, and then the toes will be down,
No. 1, the thigh part, made of wood, in which the slides move; No. 2, the
sockett part made of wood, which slides within the thigh; that part which is
black is made of boot leather to fit the stump exactly, and is fixed round the
wooden part of the sockett and to the slides; No. 3, the leg part, made of
wood, about an inch thick, shaped to a side profile Drawing of the natural leg;
the wood is cut out as in No. 8, and cork or some light material hollowed out
and cut to the shape of the leg is fixed to it; it is cut away at the lower part
behind and before to give the ancle room to move, and is received into a
mortice cut in the foot; the foot and toes are made of wood hollowed out
where strength is not required. Letter a is a piece of steel called the lock,
in the form of a cog wheel, and rivitted to the wood; when the slider is forced
down by pressure, the locking pin will fall into one of those nicks and prevent
the leg bending; for, below knee stumps, when the natural joint can be used,
the foot and ancle only are wanted, to which must be rivetted a sockett of tin,
copper, or leather, &c., as in No. 5. The form and mechanism of the joints are
the same as described for the making the whole instrument or artificial leg.
No. 4, the ancle taken out of the foot made of wood; No. 5, the sockett
rivetted to the ancle; c, c, c, c, four small straps, to which the retaining
elastic belts are fixed; No. 6, the foot exclusive of the ancle and toes; No. 7,
the toe part detached from the foot, and as above referred to and described
in referrence letter S. When the leg is taken off too near the knee to use the
natural joint, the instrument, as in Figure 1, must be used, with some devia-

page_text: tion as to materials and manner of making the knee joint, and occasioned by
the natural knee occupying the place of the artificial one, which in these and
other cases must be occasionally altered or changed, tho' what. is mentioned
are those used in general. The nick in the knee joint, which locks the leg,
need not exceed three-sixteenth of an inch, consequently scarce perceptible.
The materials of leg may be varied according to fancy, but the materials above
specified are the properest for the purpose.
In witness whereof, I, the said Thomas Mann, have hereunto set my
hand and seal, the Fifteenth day of February, in the Thirtieth year of
the reign of our Sovereign Lord George the Third, by the grace of
God, of Great Britain, France, and Ireland King, Defender of the
Faith, and so forth, and in the year of our Lord One thousand seven
hundred and ninety.
Inrolled the Eighteenth day of February, in the year above mentioned.