the smoke of furnaces has, of itself, given a large profit on the
capital invested in the works. According to Ure's Dictionary of Arts,
see vol. ii., p. 832, an English miner has constructed flues five miles
in length for the condensation of the smoke from his lead-works, and
makes thereby an annual saving of metal to the value of ten thousand
pounds sterling. A few years ago, an officer of an American mint was
charged with embezzling gold committed to him for coinage. He insisted,
in his defence, that much of the metal was volatilized and lost in
refining and melting, and upon scraping the chimneys of the melting
furnaces and the roofs of the adjacent houses, gold enough was found in
the soot to account for no small part of the deficiency.

The substitution of expensive machinery for manual labor, even in
agriculture--not to speak of older and more familiar applications--besides
being highly remunerative, has better secured the harvests, and it is
computed that the 230,000 threshing machines used in the United States
in 1870 obtained five per cent. more grain from the sheaves which passed
through them than could have been secured by the use of the flail.

The cotton growing States in America produce annually nearly three
million tons of cotton seed. This, until very recently, has been thrown
away as a useless incumbrance, but it is now valued at ten or twelve
dollars per ton for the cotton fibre which adheres to it, for the oil
extracted from it, and for the feed which the refuse furnishes to
cattle. The oil--which may be described as neutral--is used very largely
for mixing with other oils, many of which bear a large proportion of it
without injury to their special properties.

There are still, however, cases of enormous waste in many mineral and
mechanical industries. Thus, while in many European countries common