The Kimball graphic. (Kimball, Brule County, Dakota [S.D.]) 1883-1905, 1885-06-26
WEIGHING COINS
How Light Weights Are Detected at the
Bank OF England.

Bank OF England.
In another room in this department
The weighing otice-are seen the
machines for detecting light coin.
These machines are marvels of ingen-
ious mechanism. Three or fonr hun
dred sovereigns are laid in a long
brass scoop or semi-tube, OF such a di-
ameter as to admit them comfortably.
and sclf-regulating to such an incline
that the coins gradually slide down by
their own weight on to M plate of a
little balance placed at its lower ex-
tremity. Across the face of this plate
two little bolts make alternate thrusts,
one to the right. n to the left, but
at slightly different levels. If the coin
be of full weight, the balance is held
i'll equipose, and the right-hand bolt,
making its thrust, pushes it off the
plate and down an adjacent tube into
the receptacle for full-weight coin. If,
on the other hand, the coin is cver so
little light" the balance naturally
rises with it. The right-hand bolt
makes its thrust as before, but this
time passes harmlcssly beneath the
coin. Then comes the thrust of the
leit-hand bolt, which, rs we have said,
is fixed at Il fractionally higher level.
and pushes the coin down 4 tube on
the opposite side, through which it
fails into the light.coin receptacle.
The coins thus condemned are after
ward dropped into another machine,
which defacss them by Il cut half way
across their diameter, at the rate of
2o0a minute. The weighing machines,
of which there are sixteen. arc actuated
by 4 small atmospheric engine in one
corner Of the room, the only manual
assistance required being to keep them
supplied with coins. 1t is said that
$4,000 s%ovcreigns and half-sovercigns
can be weighed here in a single day.
The weighing-machine in question is
the invention of Mr.. Cotton, a former
governor OF the bank, and among
scientific men is regarded as one OF
the most striking achievements of
practical mechanics.
In the bullion department we find
another weighing machine of u differ
ent character, but in its way equally
remarkable. 1t is the first of its kind,
having been designed specially for the
bank by Mr.. James Murdoch Napier,
by whom it has been patented. 1t is
used for the purpose of weighing bull
lion, which is purchased in this de-
partment. Gold is brought in bars of
about 8 inches long, 3 wide and l inch
thick. A bar of gold Of these dimen-
sions will weigh about 200 ounces, and
is worth, ii pure, about ESQ. Each
bar when brought in is accompanied
by a memorandum of its weight. The
question of quality is determined by
the process OF assaying; the weight is
checked by means OF the weighing
machine we have referred to. This
takes the form of an extremely mas
sire PAIR of scales, working on a beam
of immense strength and solidity, and
is based, so as to be absolutely rigid,
on Il solid bed of concrete. The whole
stands about 6 feet high by 3 wide,
and is inclosed in an air-tight plate
glass case, a sash in which is raised
when it Is desired to use the machine.
The two sides of the scales are each
kept permanently loaded, the one
with single weight Of 800 ounces, the
other with a numberof weights of va
it is desired to test the weight of a bar
of gold, weights to the amount statsd
in the corresponding memorandum,
less half an ounce are removed from
the latter scale. and the barof gold
substituted ia their place. Up to this
point the beam of the scale is kept
perfectly horizontal, being maintained
in that position by a mechanical brake;
but now a stud is pressed, and by
means Of delicate machinery, actuated
by water-power. the beam IS released.
Ii the weight of the bar has been cor
rectly stated in the memorandum, the
scale which holds it should be exactly
half an ounce in excess. This or n
less excess of weight over the $50
ounces in the opposite scale is instant.
ly registered by the machine, a pointer
travelling round a dial until it indicates
the proper amount The function of
the machine, however, is limited to
weighing half all ounce only. If the
discrepancy between the two scales
as loaded is greater than this, or if,
on the other hand, the bar of gold is
more than halt an ounce less than the
amount stated in the memorandum,
an electric bell rings by way of warn
ing, the pointer travels right round
the dial, and returns to zero. So deli
cate is the adjustment that the weight
of halt a penny postage stamp-some-
what less than half a grain-will set
the hand in motion and be recorded
on the dial.
The stock of gold in the bullion
vault varies from FL, 600 to f3, OOO,-
900. The bars are laid side by side
OF small fiat trucks or barrows carry
ing 100 bars each. In Il glass case in
the vault is seen a portion of the war
indemnity paid by King Coffee, of
Ashantee, consisting of gold orna-
ments, a little short of standard fine
ness Chanabers's Jou7nul.