Engineering Wonders of the World
Volume III
Forfatter: Archibald Williams
År: 1945
Serie: Engineering Wonders of the World
Forlag: Thomas Nelson and Sons
Sted: London, Edinburgh, Dublin and New York
Sider: 407
UDK: 600 eng- gl
With 424 Illustrations, Maps, and Diagrams
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AGRICULTURAL ENGINEERING.
291
tuse angle to
The first of these is dis-
tinguished by two sets of
shares mounted on frames
set at an ob-
Two Types
of Plough.
one another
in the vertical plane fore and
aft. From each end of the
plough a cable runs to an
engine. The end to which
the pull is imparted falls and
engages with the ground,
raising the other, or free,
end into the air. The shares
are so arranged that which-
ever set of shares may be
working, the furrows shall
be turned over in the same
A BALANCE DISC PLOUGH TURNING IN A GREEN CROP.
Observe the forward (idle) limb projecting upwards.
{Photo, Messrs. John Fowler and Company.)
direction. This type of plough is most com-
monly used on land which has been under
cultivation for some time for cereal and root
crops.
The turn-round plough also has two sets of
A “ R1DGER ” AT WORK.
{Photo, Messrs. John Fowler and Company.)
shares, but in this case they are both arranged
behind the supporting wheels. When, on
reaching the end of a bout, the plough gets
the pull of the engine on the other side of
the field, it rotates through half a circle,
automatically raising one set of skives and
mould boards and depressing the other.
For ploughing in green crops discs can be
substituted for the skives and mould boards
of either type.
Subsoil ploughs are fitted with tynes be-
hind the plough bodies to break up the land
below the furrow without bringing it to the
surface, and so to improve th©
drainage while increasing the
moisture-retaining capacity of
the soil. For breaking up land for the culti-
vation of sugar-cane, beet, tobacco, and vines,
and for preparing heath for afforestation, spe-
cial ploughs are made, their strength being
proportionate to the exceptionally heavy work
which they have to perform. It is interesting
to note here that the afforestation of thou-
sands of acres of waste land has become
possible only through the agency of the steam .
plough. The following passage from the
Breslau Morgen Zeitung describes graphically
Special
Ploughs.