IMPROVEMENTS IN WEIGHING MA- CHINES
Year: 1858

page_text: LETTERS PATENT to Jean Antoine Victor Burq, of Paris, France, Doctor
of Medicine, for the Invention of "IMPROVEMENTS IN WEIGHING MA-
CHINES."
Sealed the 25th September 1858, and dated the 27th March 1858.
PROVISIONAL SPECIFICATION left by the said Jean Antoine Victor Burq
at the Office of the Commissioners of Patents, with his Petition, on the
27th March 1858.
I, JEAN ANTOINE VICTOR BURQ, of Paris, France, Doctor of Medicine, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
WEIGHING MACHINES," to be as follows:-
These improvements in weighing machines relate to the kind called bent
lever balances, and have for their object to allow of obtaining weighings of a
wider range and greater accuracy than was hitherto possible by this class of
instruments. The improvements consist in combining in one apparatus a
series of bent lever balances, each furnished with proper index and pointer,
and of a progressive force in order to agree with the various series of weights
employed for balances. The fulciment of the platform or weighing hook is
situated between two springs, as nearly as possible equal in every respect, but
situated and acting in opposite directions, thus causing one spring to be com-
pressed when the other extends itself, thereby dividing the weight equally
between both springs. The dial plates or indexes are divided in such manner
that the total amount of the divisions or units of one index represents exactly
one division or unit of the index situated immediately above or below in the
series. The devisions are inscribed on fishes or pegs, moveable when required.
The pointers or dial hands are combined and arranged in such manner that

page_text: they may, if required, be caused to run over the same distance on one dial
plate or index whatever may be the length of stroke of the springs. The
various bent lever balances of the instrument may be situated one within or
above each other, thus allowing of acting directly on each of them by its
proper suspension head, thereby permitting of measuring all the fractions of
the units of any of the indexes, either by means of an additional charge pro-
duced by exerting a direct traction on the spring balance situated immediately
below in the series, or on the contrary by causing a subtraction of these
fractions by means of proper set screws acting on the said balance. The
instrument may be applied directly to and serve as an indicator for an ordinary
or steelyard balance, and when the weight exceeds too far the ordinary limits
of common steelyards the scale of indications given by my balance may be
suitably extended by means of proper levers acting on one or the other of the
extreme indexes of the instrument, thus allowing of applying the same at
once as a weighing instrument to cranes or other apparatusses of the samo
nature.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jean Antoine Victor Burq in the Great Seal Patent Office
on the 27th September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JEAN
ANTOINE VICTOR BURQ, of Paris, France, Doctor of Medicine, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of March, in the year of our Lord
One thousand-eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Jean Antoine Victor Burq, Her special licence that I, the said Jean
Antoine Victor Burq, my executors, administrators, and assigns, or such others
as I, the said Jean Antoine Victor Burq, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN WEIGHING MACHINES," upon the condition (amongst others)
that I, the said Jean Antoine Victor Burq, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,

page_text: and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Jean Antoine Victor Burq, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement:-
These improvements relate to the class of weighing instruments called bent
lever or spring balances, or dynamometers, and have for their object to allow
of obtaining weighings of a wider range and greater accuracy as was hitherto
possible by the said class of instruments, while at the same time they may be
adapted to any system of weights. The construction of my improved instru-
ments is based, 1, on a double compensation of the springs, viz., a spontaneous
compensation similar to that made use of sometimes for clockwork pendulums,
and which is obtained by causing the suspension of the weight to take place
between two spiral springs of exactly the same range, force, and disposition,
one of which springs is caused to contract while and in the same measure as
the other spring is caused to extend, and a voluntary or changeable compen-
sation obtained by substituting for the fixed quadrant divisions of the ordinary
spring balances, moveable divisions, the position of which may be altered accord-
ing as required. 2, on a manner of decomposing the weight so as to allow the
indication on several dial plates or other indicators of the fractions of a given
unit, or of the multiples thereof, the indication of these fractions or multiples
taken place if possible according to the decimal system, and being distributed
on the required number of corresponding springs, which springs, if required,
may be situated in a concentric position to each other and inserted in a suit-
able tube or casing, cach set of springs being allowed either to act separately
by means of a suitable mode of suspension, or all the sets in combination with
each other so as to make it possible of increasing or of decreasing ten times,
hundred times, or more, the indication of the corresponding dial plate, it being
further understood that instead of the spiral springs any other suitable form of
springs might be made use of. Each division or unit of a dial plate or
indicator requires to be exactly equivalent to the amount of all the divisions
of the dial plate or indicator just inferior to him in the seric.
I will now describe some arrangements of my improved dynamometer
spring, or bent lever balances to which the above-mentioned principles have
been applied, and I will thereby refer to the annexed Drawings.
Fig. 1 is a front view, and Fig. 1 a vertical sectional view of one of my
arrangements of spring balances; Fig. 2 represents a modification thereof,

page_text: In these Figures corresponding parts are indicated by the same letters of
reference. The instrument consists of a dial plate or quadrant A with 3 con-
centric divisions A', A2, A3, for three dial hands B, B', B, turning round the
same fulcrum O one behind the other, but so as not to come in direct contact
with each other; the small arms b, b, b, of each of these hands have a slot
in which a screw nut & glides over a spindle 6, provided with a corresponding
screw thread, thus allowing of advancing more or less the said nuts b¹, and
consequently the rods C, C1, C2, the other or upper ends of which latter may
suitably be fixed in a slot c, established in the front part of the bent arms
D, D1, D2, corresponding with the rods C, C', C2, the lower end of which bent
arms are respectively fixed to the rings G, G', G, acted on by the springs of
the instrument. The dial plate A is provided with a moveable cover, part of
which is shown in the Drawing as cut off in order to allow better to judge of
the entire arrangement. The springs are inserted in a tube or casing E
provided in part with suitable slits through which pass the bent part of the
arms D, D', D; E, E¹, E', are hooks for ascertaining the weight of the
bodies to be weighed. The entire instrument is suspended from above by a
hook E³ connected to a cross rod E* fixed to the casing E, in the lower part
of this casing E' is fixed a small tube G³ to which is fixed the lower end of
the spring F, the upper end of which is fixed to a ring G, to which is also fixed
the lower end of another spring F¹ similar to F; the upper end of F¹ is fixed
to the cap D³. In the interior of these springs is situated a sort of tube
formed of four flat arms II, two of them fixed to an upper washer I and the
two opposite ones to a lower washer so as to glide in opposite directions of each
other. To the first-mentionned arms are fixed two washers I' and 12. To the
washer I is fixed the lower end of the spring F2, the upper end of which is
fixed to a ring G, to which latter is also fixed the lower end of a similar
spring F, the upper end of which is attached to the washer I, to which
washer is also connected the lower end of another spring F, the upper end
of which is attached to the ring G2, to which is also fixed the lower end
of a perfectly similar spring F, the upper end of which latter is fixed to the
washer I. The springs F and F act in opposite directions to each other,
but otherwise they are perfectly similar in their effect, that is to say, that
when one of them, F, for instance, is caused either to contract or extend
for a certain length, the other spring F is on the contrary caused to extend or
to contract for the same length of stroke. The hook E is connected to a
cross-head K fixed to two vertical rods L, the upper end of which is fixed to
the ring G, the hook E¹ is connected to a cross-head K' fixed to a screw M,
forming the lower end of a hollow spindle N, connected to the ring G by

page_text: turning a screw nut m, and pressing the same against the lower end of the
tube E, the hook E' may be lowered more or less with great nicety. Through
the hollow spindle N passes another spindle N', to the lower end of which is
fixed the hook E, which by a similar arrangement as that of the nut m, may
be pressed down very nicely; this spindle N₁ is made of two blades forming a
spring, by which effect the same adheres with sufficient firmness to the ring G².
The mode of acting of this arrangement will be now readily understood. Sup-
posing the instrument to have been fixed by means of the hook Es to a fixed
point, and the weight of a body or of a traction to be ascertained, this body or
the cause of the traction is connected to the hook E, which will consequently
cause the corresponding band B to move over the dial plate. Supposing we
wish to weigh with the English system of pounds and ounces, the circle A² has
equal divisions marked on it by means of the numbers I, II, etc., to X; the
under part of each number is marked in another colour as the upper part; thus
the half of each number is marked, for instance, in red (corresponding with the
colour of the hand B), whereas the other or upper half of the numbers is
white, corresponding with the hand B¹, the force of the springs F*, F³, being
regulated in such manner that each division corresponds with a pound. The
circle A¹ is likewise divided from 1 to 10 by division marks, and the force of
the corresponding springs F, F, regulated so that each of these divisions repre-
sents 10 pounds; on the other hand the circle A³ is divided in 16 equal parts,
and the force of the springs F, F, is regulated so as to make each division
correspond with one ounce. Supposing now that by the effect of the weight
on E the hand B is arrived on a certain point of the index A, for instance, in
the division corresponding with VI, this will show the weight to be V x
10 lbs. an amount which is now to be ascertained by causing the hand B to
be brought back to the nearest division point, which may be done by means of
the nut m; if now, by this motion, the hand B' be now, for instance, arrived at
the division point VIII exactly, then this would show the weight to be 4 ×
10+8 48 pounds; but if the hand B' had arrived between the divisions VII
and VIII only, it would be required to ascertain the exact quantity it is
gone beyond VII; for this, I cause, by means of the nut m, the hand B to
advance, by which the other B₁ will retrograde, till both are arrived at the
same distance from the next division points, that is to say, IV and VII;
in order now to ascertain the quantity of the difference left, the part m³, m²,
which, in respect to the hook E2 corresponds with the nut m, is lifted up
against K, the hook E2 is drawn downward, and the remainder of the
distance is performed by causing the screw nut m² to turn; the band B² will
be moved forward over the circle A3 till the hands B and B', which hereby

page_text: move also, are arrived exactly at their next division point; the hand B will
then show the number of ounces. Thus, for instance, if this hand had thus
stopped on the division 6 this would show the weight to have been 47 pounds
+6 ounces. In order to make the indication of the hands always exactly
commence from 0, the end 7 of these hands are allowed to turn more or less
round a small spindle r at the end of the hand. I must also state, in order
to diminish the descent of L to take place by means of the screw M only,
which would require too much time, a ring P is applied against the lower end
of Es, which ring is provided with two bent levers Q, R, S, having their
fulcrums in R, the arms R, S, of which levers are lifted up by small springs
T, whereas the other arms are provided with holes r, which may be put on
two pins t fixed in the tube E³, thus allowing of lifting or lowering the said
ring P and keep it fixed in that position, after which the action of the nut m
takes place against this ring P in the manner as has been described.
Fig. 2 shows a vertical section of the general arrangement of a modification
of the instrument just described, but provided only with the system of double
springs F, F, and F, F, and further parts. In this instrument the action
of the parts m, m³, is combined in different manner; the hook E³ has its
rod N¹ fixed in n to the ring G2; on the other hand another rod N2 is situated
in the prolongation of the first one; this rod N2 is provided with a knob P,
and glides with great friction in a hollow screw N³, to which the ring G³
serves as nut; at the lower end the rod N2 is provided with a tube N' forming
cap, in which is inserted the upper end of N' for working the hook E²; the
rod N2 is pushed down through the screw N³ till the cap N+ presses on the
end of N¹, and then the same is done as with the nut m³ by turning the rod
N2, and consequently the screw N*, whereby a gradual pression will be exerted
on the rod N¹, and consequently on the hand B2 for the ounces.
Fig. 3 shows a front elevation, and Fig. 3* a longitudinal sectional view, of
another arrangement based on the same general principles. In those two
Figures corresponding parts are indicated by the same letters of reference.
A and A are two dial plates, the plate A¹ serving for indicating the sub-
divisions of A; two hands B and B with suitable moveable division points or
marking pegs y to be fixed in any suitable position by means of set screws e;
to the spindles and n¹ of the hands B and B are fixed pinions f and f
acted upon by racks 9 and g¹, gliding in suitable guides over the tube or
casing h, in which latter are contained the actuating springs, and which is
provided with a counterweight h¹; to this tube h is fixed the dial plates, and
the entire may be suspended from the top by a double bent rod or hook H,
between the two forked arms H¹ of which is suspended an ordinary steelyard

page_text: C, having its fulcrum in C¹; the arms II' are fixed to the plate D, situated
between the two springs F and F¹, and which plate acts on the rack g, and
consequently on the hand B; the lower end of the spring F' is connected to the
fixed ring G', through which passes the spring F fixed to a second plate D¹,
to which plate is further attached the spring F³, the lower end of which rests
on the bent part i of the plate I, the other end of which plate is fixed to the
ring G, to which is connected the upper end of the spring F, and from which
ring descends a tube D, to the end of which is fixed the spring F; through
D¹ passes a spindle K with suspending hook L', which spindle is fixed to D¹.
K3 is a sort of double bent crutch, the two arms K³ of which act as springs
against the lower ends II of the arm H¹, so as to allow of keeping the crutch
Ke fixed at any required height. When the operator acting with his hand
on the two projecting arms K, pushes the crutch downward, and causes this
latter to act against a projecting pin K fixed to the double bent part K³, one
end of which part is connected to the rack g' and the other to the upper end
of the spindle K. To the lower end of the tube or casing his fixed a hook I.
by means of a screw M, so as to allow, if required, of turning the said hook
aside in such manner as not to interfere with the hook L. To the bent part
K' is fixed a blade K³, on the top of which the steelyard C may be caused to
act, as shown in the Drawing; or this steelyard C may be lifted up and kept
in a suitable position by means of a stop N, from which is suspended the said
steelyard, which is provided with a counterweight Q gliding over the arm P,
provided with suitable divisions, whereas the other arm R has also divisions,
and a moveable index weight S, and from the end T is suspended a scale u.
The mode of working with this instrument is as follows:-The entire being
suspended by means of the hook H to a fixed point, the burden, the weight of
which is to be ascertained, is suspended to the hook L, whereby the casing h
will be caused to descend and the plate D lifted comparatively, thereby
causing the spring F to contract and the spring F to extend; the casing hon
descending causes the rack g¹ to descend, the extent of which will be indicated
by the hand B on the dial plate A; if the hand had thus arrived, for instance,
between the division pegs marked on the top X and XI, and if each division
is equivalent to one pound, then this would show the weight to be between
10 and 11 pounds. In order to have the exact value, let us suppose the
divisions of the upper plate A represent each of those on A, that is, one
ounce; having pushed and kept the hook L aside by means of the set screw
M, the operator draws on the hook L' till he brings the hand B at the next
division point XI, by which the hand B¹ will have travelled over the dial A',
and be arrived, say, for instance, exactly at the division point marked 6,

page_text: which would show the operator had been obliged to exert a traction of
6 ounces in order to bring the weight exactly to 11 pounds, and that cou-
sequently the exact weight is 11 pounds 6 ounces or 10 lbs. +10 ounces. In
order to avoid, however, this calculation, the marking pegs of A have two
indications inscribed on them, and marked in different ciphers, say, Roman
The
and Arabian ones, in order better to distinguish them from each other.
upper ones or Roman ciphers, for instance, mark one number more than the
lower or Arabian ones; thus, for instance, on the peg marked with the
Roman XI is found also the Arabian 10, and so on; on the peg of A¹ the
numbers are also inscribed in double from 0 to 16, the upper ones beginning
from the left-hand side, and the lower ones from the right-hand side; thus wo
have only to remark the lower number of the peg on which the hand bad
stopped (which in this case would be 10), and add this number to the Arabian
10 of the dial A', giving in all 10 pounds +10 ounces; if, however, the hand
B' had not stopped exactly on the number VI of A', in order then to ascertain
the difference left, the operator pushes the crutch so far up as to free the
blade K, after which he pushes the weight Q to the number 6 marked on
the lever arm P of the steelyard, which will cause the hand B' of A¹ to come
exactly on the number VI, and he advances now the counterweight S till
the hand B of A arrives exactly at the division point XI. Supposing that to
effect this the weight S had advanced to the number 4 (the numbers inscribed
on the lever arm R correspond with drachms,) then the exact weight would
consequently be 10 lbs. + 10 oz. + (164) drachms, the entire number of
divisions on R corresponding with 16 drachms; the entire weight would
consequently be 10 lbs. + 10 oz. + 12 dr. If I wish to measure only small
weights under the pound, I then fix the weight to the hook L', and perform
in respect to the hand B' the same operation as that just described in respect
to B, with the exception, however, that the counterweight Q remains in its
original position at 0; thus, if the hand B' by this weight had, for instance,
arrived between the numbers V and VI of A', then, having lowered the
steelyard on K, the weight S is caused to advance along R till B' arrives at
VI, which shows that I have to deduct from the number of drachins indicated
by S the 6 ounces indicated by B. For weighing very small weights the
burden is put on the scale u. If now it be supposed, for instance, that the
length of x, y, be 10 times that of y, C¹, then if the handle B' had by the effect
of this weight stopped between the divisions 0 and I of A¹, and that by
advancing S to the division point 6 of x, y, B' comes at the division point I,
then this would show the weight in u to be 1 oz. 10 dr.
10
10
6 drachms

page_text: Another arrangement based on the same principles as those above described.
is shown partly in a front view in Fig. 4, and in vertical section in Fig. 4*,
corresponding parts being indicated by the same letters of reference as both
Figures. This instrument is particularly useful for weighing heavy loads, and
be applied to cranes, scale balances, or weigh bridges. The construction
of this instrument is very similar to that of Fig. 1, it is provided with three
pairs of compensating springs marked 1, 1, 2, 21, 3, 3¹, moveable plates
P, P, P; weighing hooks C, C3, C³; racks R, R, R³, for moving the
hands A1, A2, A3, indicating three dials arranged on the same dial plate; the
said hands have different fulcrums, and turning, respectively towards the right
and left hand side of a tube or casing containing the springs, &c; the instru-
ment is further provided with a system of rods, screws, and adjusting nuts
M', V, E, X', X2, for acting on the two large hands in similar manner to the
arrangement described for this purpose in Fig. 1, and serving for fixing
the second pair of springs, and consequently its hand on the first pair of
springs or its corresponding hand. In the central part of the instrument
exists a further combination of rods provided with screw threads and nuts
E, E, acting according to the same principle as the parts N', m³, m³, of
Fig. 1, that is, for fixing the 3rd pair of springs and corresponding hand
on the first and second ones. The mode of operating this instrument differs
from that described in Figs. 1 and 1, in as far that the springs instead of being
all kept fixed in one unvarying point D¹ and acting from below towards the
top in order to lift the load and indicate on their dial plate the fractions of
the unit of the next dial, they all descend, viz., the second springs charging
the first one and the third spring charging the two others, thereby causing the
three hands to move forward instead of receeding. Instead of causing the hands
simply to rotate over a quadrant or fourth part of a circle, the raks are
arranged so as to make them perform an entire revolution, and the large hand
even twice this way, thus allowing to leave a greater distance between the
indicating marks on the dial plates, and consequently an easier ascertaining
of the motions of the hands, which is of particular importance when the
markings of a dial are to be increased ten times, a hundred times, and so on, by
the aid of a system of levers. In the centre of the spring 1 is situated a
screw, serving for lowering or for raising the instrument with its load to the
fixed point, when, as is shown in Fig. 1, the principle lever arm of the lever
arrangement, Fig. 5, to which the instrument is applied, requires to be brought
back to the horizontal position; a second screw serves for fixing the instru-
ment on a crutch or bent standard of a weighing bridge, Fig. 6. To the end
of the rod M may be screwed either a second rod M' or a hook C, Fig. 8;

page_text: -
this rod M has at the lower end two screws threads U and U¹, which may
take either in the female screws E' or e², so as to act either on the springs 2
or on the springs 1. The mode of acting of the instrument is as follows:-
If the same is to serve directly as weighing instrument by itself, I suspend
the instrument from a fixed point by means of the hook C, Fig. 8, and attach
the load to C¹. Supposing the hand A¹ to have arrived at the point 2 by the
rotating of the hand, a small index I connected to the top of the rack R' is
caused to advance over a scale Q divided in two halves, each marked with a
different colour, viz., black for the 1" turn of the hand, and red for the
second turn, with which turnings correspond likewise the red and black
ciphers inscribed on the circle Z. Now let, for instance, the hand A¹ be
arrived between the two red divisions XVIII and XIX, the weight is thus
10 times 19 or 190 pounds, which is to be deducted; however, a certain
weight, the amount of which I ascertained by lifting the part V along the
rod M³ till the hand A¹ arrives on the division point XIX, if the band A² had
arrived by this motion between the points VI and VII of Z, this would
shew the weight to be 190 6 pounds a certain quantity, for ascertaining
which by unscrewing the nut E by which the distance between X1 and X2 is
increased till both hands A¹ and A' arrive at the same distance beyond the
centre of the division points, or of the two small circles Z³ and Z', which causes
the 3rd hand A3 to travel; supposing this hand A³ to be arrived at XI; this
will show the total weight of the load to be (190-6) pounds 11 oz. = 180
pounds 4 pounds + 5 ounces, as indicated by the small Arabian ciphers
situated at the side of the above Roman ones. If the hand A³ had advanced
beyond the point XI, this small difference could easily be ascertained by the
eye, the instrument serving only for heavy and not for small weights,
which is the contrary of Fig. 1, and the weight would consequently be
184 pounds × 5 ounces, say, for instance, or of an ounce. Just below
the circle Z is situated a second one Z, on which the divisions of the pounds
are given in decimal fractions instead of in ounces. For weights of from
10 to 200 pounds, I act in the manner just described, but for weights above
200 pounds, say, for instance, those 10 or even 100 times heavier, such as are
weighed generally from cranes, I suspend the instrument to a system of levers
represented in Fig. 5, consisting of two standards A and A¹, connected together
by two cross beams B and B', the latter balancing in on a hook Z, by which
this lever arrangement is attached to the crane, whereas I suspend the spring
balance to the fore-end of B¹ by means of the hook C, Fig. 4. In the lower
or forked end of A¹ turns a lever L on a spindle c', the other end of which
lever acts on the fraction roller q of Fig. 4; this lever L is inserted in the

page_text: forked or lower end of the standard A. A hanger 1, P, suspended from L
serves for transmitting to L² the effect resulting from the lever L', to which
latter is suspended in l, the hook Z; this arrangement is combined in such
manner that the points and are in the same vertical line, and the length of
their arms are regulated so as to make a weight of 100 pounds suspended in
Z2, make equilibrium with a weight of 10 pounds suspended at C', that is,
10 times the quantity of the weight before suspended at C', so that if, as in the
example given here above, I had found 184 pounds + 5 ounces 184 lbs.
+of a lb. 184-3 pounds, this would show that the weight of the
load suspended at Z2, and producing this indication on the dials of the spring
balance is really 184 3 pounds. If, instead of increasing the indication tenfold,
I wish to increase it a hundredfold, it would then be required to alter the
lever arrangement accordingly. I must observe here, that for weighing the
lever arm, L2 must always be brought to the horizontal position by means of
the screw V, Fig. 4. In order also to allow of keeping the hook C in the
vertical position in respect to the instrument, this hook may be fixed by means
of a screw W, or any other suitable contrivance. For weigbing small weights
under ten pounds, say, for instance, I suspend the load to the hook C³ corre-
sponding with the hand A2, and I further obtain the subdivisions by pulling the
hook C³ till I see the band A2 on the dial Z3 come nearly at à division point,
and I then complete the operation by causing the rod a to perform a quarter
of a revolution, and as the upper end of this rod is split and forms a spring in
the oval opening of the tube t, the said upper end will become so firmly
inserted in the tube t as to allow of turning by means of it the screw V³,
which will consequently cause the ring P to ascend with the utmost exactness;
which operation I continue till the hand A and A2 be arrived at a fixed
division point. If the instrument is to be applied for weighing with a weighing
bridge, I then make use of the arrangement shown in Fig. 7, in which u
represents a bent standard or crutch fixed to the upright or pillar of the
weighing bridge, in which standard is a slit through which passes the beam L
of the bridge; the instrument is then turned topside down, and in this position
applied to the crutch of the bridge, the rod M. being passed in a slot in the
bent part of this crutch, so that the fraction roller G comes to act on the
suspension knife of the beam L, the position of this knife having been
previously suitably shifted, so as to be situated lengthwise instead of crosswise
on the the said beam. The spring balance is further fixed to the bent part u¹ by
means of the screw nut V, and after having brought equilibrium, the hand on
which is to be acted, the entire is ready for use. Fig. 7 shows my spring
balance of Fig. 2 applied to an ordinary scale balance.

page_text: Having thus described the nature of my Invention and the manner of
putting the same into practical effect, I declare that I claim as my Invention
the application to what are called bent lever or spring balances or dynamo-
meters, of,-
1. The above described arrangements in which the burden is distributed
between two or more springs, the latter producing their effect in contrary
directions to each other, so as to form a spontaneous compensation in the
action of the said springs, the effect of which latter is shown by means of dial
plates or other indicators.
2. Having the dial hands, division points, or marking pegs on the various
dial plates or other indicators ensily moveable by hand for thus allowing to
shift their respective position, but so that constantly a suitable relation be
existing between the various indicators, the hand being allowed if required to
perform one or more revolution over the dial plate.
3dy. The mode of indicating the weight on several dial plates or other
indicators, the divisions of each of which bears a certain relation with those of
the remainder ones, thereby allowing to indicate either the subdivisions or the
multiples of a unit of weight taken on one of them.
4. Combining with the above-described instruments a system of levers for
suitably increasing or decreasing the unit of indication.
6. The arrangement described for allowing to increase the distance
between the marking points, by causing the hands to perform more than one
revolution over the dial plate.
7. The application of the described instruments and of the principles on
which they are based, for obtaining weighings with ordinary scale balances,
weigh bridges, cranes, or other similar instruments in which the weight of tho
burden or an effect of traction are to be ascertained.
In witness whereof, I, the said Jean Antoine Victor Burq, have hereunto
set my hand and seal, this Twenty-fifth day of September, One thousand
eight hundred and fifty-eight.