, 1913-08-23

cent trials conducted by the Colonial Com
mittee, Berlin; 'On a mild sandy loan the
motor-plough worked nearly 1,73 acres in
one hour to a depth of ST inches. The field
was 700 yards long. aud of q convenient
shape. Another day, LAS acres per hour
was ploughed to y depth of 81 inches. lastly,
in consequence of several stoppages due to
the field not being sufficiently dry. only 0.99
acre was p~loughed per hour to u depth Of
II inches. The consumption of benzlne was,
under the favourable conditions of the first
day. only 1913 fb per acre, but on an aver
age, in practlce, it ranges from lab to 1876
h per acre. The power dew 4loped, as re-
Clustered by a break d~ynamometer, was 1873
hip.
The techuical success of the machine just
discussed gave slim illus to other Inventors
to create improvements, particularly as re-
CARDS change of gear and reversing. Tue
former operation Is important III connection
with the cultivation Of unduiating lanl re-
verSlng is still more essential, for if IN un-
reversible machine happens to be brought
up against u large stone or any other such
obstacle, the mortifyin9 and expensive pro-
cedure Of Invoking the aid of horses to shift
1T becomes absolutely necessary.
Several new machines of the Stock type
eventually appeared on the German IN Grket,
Out NSlJ low nHN0 SuCNlN6O. III II I6C6ub
publication, reference is mtde to a IN )tor-
plough of the S ock typo, the wheels of
which are equ pped with shovel p)ints (to
prevent s~llpp.ng) which can be thrown fiat
against the rim when travelling over hard
road. This would appear to be a feature of
some practical Importance.
OF late, manufacturers seem to have turn
ed their attention rather to the construction
of disc motor-ploughs. Po4ls patent mDtor-
plough, for instance, carries in front Of every
plOughshare 4 revolving coulter for dimiu-
lshing resistance. This feature makes Pohl's
plough resemble, somewhat, those nacuine4
which till the soil not by means of plough
shares, but by revolving hoes. la such nl-
chimes, the diver sits IN front of the three
wheeled vehicle which, in the distance, is
said not to be at all unlike 40 ordinary au-
tonobile.
AS regards the efficiency of disc motor
ploughs, little data is available for prouounc-
ing Il final judgment. Experience shows
they require more power to work them than
ordinary motor-ploughs. On tho other hand,
their work is more intense, since the discs
produce a fue filth during a single opera
ton. Another advantage which they Offer
is the fact that the discs work in the same
direction as the driving VIII ,eIs, and al
though they mly not actually propeI, they
do not act rs brakes, as ploughshares do.
One disadvantage of the disc is that it is
liab to cut up and distribute couch grass,
and orher perennial weeds.
In considering motor cultivation, the dis
t%inction between the self-containei imple-
ments just discussed, and the American
tractor machine must always be borne in
mind. These tractors haul other implements
besides ploughs. Ia the case of tbs plough4
al advantage is gained under this system
III that the shares are independent AM yield
ing also disc-ploughs cIn be substituted
a convenient matter, when, for instance,
ease of penetration aud a sort of cutting eff
ect is desired, as in turning unler long pen
manure or green dressings.
Tractors, at present, are employed in prac-
tice more extensively than the self
contained machine. Iu the western Uni
ted States they are fairly comm )nly
used, and are likely to become still more
general. P. S. Rose has lately collect
ed data from thirty-six agricultural col
legeI in the Unite States to show that IL
somewh 1t deeper %pIoughing is needed there
to obtain the best crop yields. TO double
a 4 to 8 iuch depth of ploughing, at least
SO per cent. more work animals would be
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