The Glasgow courier., 1916-01-28
POWER OF GAS TRACTORS.

| he TdpIO pTOSTSSS WHICH mas bee
occurring in the development of tn
farm gas tractor and the CONSTANT
increasing number of men who ar
purchasing or contemplating the pur
chase of one of these outfits seem I
warrant the issuing Of some inforca
tion with regard to feature concern
ing which there is considerable con
fusion, i. e., the power ratings q
tractors.
Nearly everyone knows the defin,
tion of a horsepower" as given il
school arithmetics, etc., namely, eth
power required to raise weight o
$4,000 pounds to height of one foo
in one minute" AS this is a definit,
fixed unit of power, one would natur
ally suppose that the horsepowe
ratings of two tractors would be ;
logical and reliable means of compar
ing their ability to perform work
that tractor rated at 30 horsepowe,
on the drawbar would be twice a.
powerful and capable of doing twice
as much work as one rated at II
horsepower on the drawbar, for exam.
pie. This supposition would be cor
rect but for the fact that there has
been no definite standard used in as
certaining the horsepower developed
by tractors and the percentage of the
power actually developed, which
should be taken for their catalogue
rating. The various manufacturers
have followed their own judgment in
the matter and, as result, several
methods Of rating are being used,
with a consequent lack of uniformity.
It is because of this fact that, at
the present time, it is quite common
to find two tractors doing practically
the same amount of work and clearly
of about equal power, although with
widely different catalogue ratings. It
is obvious that either the outfit with
a low catalogue rating has been un-
ierated by it's manufacturer or that
The second machine has been over
'ated or, perhaps, both have occurred.
It would seem advisable, therefore,
hat steps be taken to bring about
standard rule for ascertaining and
the horsepower of tract
'rs. It is not so important, perhaps,
What particular method is followed so
ong as the same method is used by
ii manufacturers, thus avoiding hav-
ng machines of the same power given
uch varying ratings.
A movement is already on foot in
he department to bring about the
doption of some standard. Until one
as been decided upon and adopted,
is suggested that farmers, in COM
airing different makes of tractors,
hould give particular attention TO
he number of plows pulled and the
mount of work done by. the various
and that less attention be
aid to the catalogue ratings. 4
When outfits can be seen working
ide by side, as at the tractor demon
trations which are being held
the country, the amount of
'ork done is of more value in COM
airing the relative power than are the
ratings, unless exact
= the same method has been used in
ach case.
It is obvious that two tractors
ach pulling the same number of
lows of equal size, at equal depth,
A the same soil, and each moving at
he same speed-are exerting practic-
lily equal amounts of power on the
rawbar. In such case, if each is
ulling its normal load, they should
ave the same drawbar rating. 1t is
OF at all uncommon, however, as
reviously stated, to find tractors un-
er such conditions with widely diff
erent ratings. BY using as stand
I'd the amount Of work done by diff
erent tractors, therefore, very fair
of the drawbar horse
ower can be obtained. With this
nown, good idea Of the power Of
he motor can be gained. If, in the
ase just mentioned, one of the ma
hines was considerably heavier than
he other, it is apparent that it would
equire more power to move its own
Weight and that it would therefore
ot be capable of exerting on the
rawbar as large a percentage Of the
motors total power as would the
ther machine, assuming that the loss
+ power through gears, etc., in the
was the same. It nat
lrally follows that the motor on the
leaviest machine would develop more