The most interesting place connected with the machinery of the Bank of
England is the Weighing-Office, which was established about 1840. In
consequence of a proclamation concerning the gold circulation, it became
very desirable to obtain the most minute accuracy, as coins of different
weight were plentifully offered. Many complaints were made, that
sovereigns which had been issued from one office were refused at
another; and though these assertions were not, perhaps, always founded
on truth, yet it is indisputable that the evil occasionally occurred.
Every effort was made by the Directors to remedy this, some millions of
sovereigns being weighed separately, and the light coins divided from
those which were full weight. Fortunately, the Governor for the time
being, (Mr. W. Cotton), before whom the complaints principally came, was
attached to scientific pursuits; and he at once turned his attention to
discover the causes which operated to prevent the attainment of a just
weight. In this he was successful, and the result of his inquiry was, a
machine, remarkable for an almost elegant simplicity. About 80 or 100
light and heavy sovereigns are placed indiscriminately in a round tube;
as they descend on the machinery beneath, those which are light receive
a slight touch, which moves them into their proper receptacle; while
those which are the legitimate weight, pass into their appointed place.
The light coins are then defaced by a sovereign-cutting machine,
remarkable alike for its accuracy and rapidity. By this, 200 may be
defaced in one minute; and, by the weighing machinery, 35,000 may be
weighed in one day.
An eminent member of the Royal Society mentioned to the writer, that,
amongst scientific men, it is a question whether the Weighing-Machine of
Mr. Cotton is not the finest thing in Mechanics; and that there is only
one other invention--the envelope-machine of De la Rue--to be named with
it.--_Francis's History of the Bank of England._
------------------