History of the Plow
Plows are thought to
have been invented in Mesopotamia in approximately 3000
BC.

Plows in the ancient
Greek culture were very simple devices, which would be improved in
Roman times. Sometimes a wheel was added to improve the
functioning of the plow.
In China, plows made of iron were in use in in about 300 BC, and
moldboards, which turn the soil over in a furrow, were in use in
the first centure BC. Moldboards were not used in Europe
until the late 10th centure. When Chinese agricultural
implements were shown in Holland in the 17th century, they were far
in advance of European technology.

The Roman plow was
adequate for plowing the dry Mediterranean soils, but proved
inadequate for the heavier soils of Germany and northern
Europe. A heavy plow was developed for those
regions.

A heavy plow of medievel
times.
In the American colonies, early plows were imported until the local
blacksmiths learned how to make them. An early advancement in
plows came from Thomas Jefferson.

Jefferson's "Moldboard
of Least Resistance"
After observing European plows while ambassador to France, he
developed an improved moldboard, which was designed to work with
the soil found in Virginia, and to turn the earth as efficiently as
possible. He called his plow the "moldboard of
least resistance."
The first American plow made of cast iron was made by Charles
Newbold in 1797. The figure below is from his
patent.

The disadvantage of this
plow was that if it was broken, the whole plow had to be
replaced. This problem was solved by the plow of Jethro Wood,
which had iron parts which were interchangable. Thus, if one
part was broken, it could be replaced.

Jethro Wood, US Patent #
X3130, 1819
The next big improvement in American plows came when blacksmith
John Deere made a plow with a steel face. The problem that
had developed was that farmers in the newly settled prairie found
that their heavy soil stuck to the cast iron moldboard of their
plows. John Deere made a plow with a steel moldboard, which
was self polishing in the grassy soil, and to which the soil did
not stick. He first used steel saw blades and welded them to
the iron mouldboard. John Deere, US Patent # 46454,
1865



From Patent Pending Blog - Patents and the History of
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