RS

Nineteenth century]

In 1779, Richard Dearman was granted an English patent on a new method
of making mills for grinding coffee. In 1798, the first American patent
on an improved coffee grinding mill was granted to Thomas Bruff, Sr. It
was a wall mill, fitted with iron plates, in which the coffee was ground
between two circular nuts, three inches broad and having coarse teeth
around their centers and fine shallow teeth at the edges.

De Belloy's (or Du Belloy's) coffee pot appeared in Paris about 1800. It
was first made of tin; but later, of porcelain and silver--the original
French drip pot. This device was never patented; but it appears to have
furnished the inspiration for many inventors in France, England, and the
United States. The first French patent on a coffee maker was granted to
Denobe, Henrion, and Rouch in 1802. It was for a
"pharmacological-chemical coffee-making device by infusion." Charles
Wyatt obtained a patent the same year in London on an apparatus for
distilling coffee. The De Belloy pot is illustrated on page 622.

In 1806, Hadrot was granted a French patent on a device "for filtering
coffee without boiling and bathed in air." This use of the word
filtering was misleading, as it was many times after in French, English,
and American patent nomenclature, where it often meant percolation or
something quite different from filtration. True percolation means to
drip through fine interstices of china or metal. Filtration means to
drip through a porous substance, usually cloth or paper. De Belloy's pot
was a percolator. So was Hadrot's. The improvement on which Hadrot got
his patent was to "replace the white iron filter (sic) used in ordinary
filtering pots by a filter composed of hard tin and bismuth" and to use
"a rammer of the same metal, pierced with holes." The rammer was
designed to press down and to smooth out the powdered coffee in an even
and uniform fashion. "It also," says Hadrot in his specification, "stops
the derangement which boiling water poured from a height can produce. It
is held by its stem a half inch from the surface of the powder so that
it receives only the action of the water which it divides and
facilitates thus the extraction which it must produce in each of the
particles."

[Illustration: EIGHTEENTH-CENTURY ROASTER

Essex Institute, Salem, Mass.]

A coffee percolator was invented in Paris about 1806 by Benjamin
Thompson, F.R.S., an American-British scientist, philanth