El Paso herald. (El Paso, Tex.) 1901-1931, 1914-03-21
Copyright, 19f4, by w. s.. Stewart, d.


I am curious to learn what IS meant
bv the term thermal efficiency Also
what IS meant by "heat unit. am
told the horsepower Of motor IS
measured in heat units, and would
like to know how many neat UNITS
constitute a horsepower. Some 1n1Or-
nation regarding this viii be apprec-
iated-OWner.
The horsepower Of a gasoline motor
IS measured in heat units. The eff
cheney of the motor depends upon the
actual number Of heat units converted
into mechanical energy. Heat is a
form Of energy which IN turn mas
certain capacity for doing mechanlcal
work. and this mechanical work in
turn is measured in foot pounds. one
B. r. u. is equivalent 20 772 foot
pounds; one foot pound being equal 10
that energy required TO raise one
pound through one foot OF space. a
b T. Z. being that amount OF heat re-
ouired to raise one pound OF water
from SO to 40. degrees Fahrenheit. One
horsepower being equivalent to 53,OOB
foot pounds Of work done in one
minute.
Motoring Department, The Herald
] have read at various times IN jour
nails and especially tire books about
the proper initiation OF tires nave
seen four Al cages all OF the same
make tested on the same tire ana each
gage reading different
AS I realize that OverinflatIon IS
about as injurious as unoerlnLIaLlon'
would you kindly state, OF possible
without a lot Of expensive apparatus
IS it hard for the average motorist 70
tell whether his gage is right or not
The various articles have read DO not
bring out this point-W. A Z.
1t is rather difficult to make a prac-
teal and accurate tests Of tire gage.
If you are in doubt at to whether the
tire is sufficiently inflated you can
always gage very closely by noting
with the eye how the tire rests on the
ground. When tire is not properly
inflated it viii stand more or less flat
at the point of contact with the
ground. When it is sufficiently IN
flated it should stand up fully off the
ground without any bullying effect. In
brief, a tire should always be inflated
so that when in service the side walls
of the tire viii not work. If the
various layers OF fabric work, weak
spots soon develop and blowouts re-
suit
Motoring Department, The Herald
VIII you kindly give me some 1n1Orma-
ton on the following;
I am considering building light
delivery wagon Of 1 ton capacity and
would like to know what type spring
suspension you think best suited Tor
the purpose. One Of my friends ad-
vfsed me to put on the semi elliptic
stal the three quarter elliptic type
Kindly advise me through your col
unns which you think best
Thanking you for the favor, an,
your very truly, R 7. o.
The semi elliptic type springs are
more practical for commercial pur-
poses than the three quarter elliptic
type 1t would not be practical to use
the three quarter elliptic on a one ton
delivery wagon. The semi elliptic can
be anchored to much better advanta-
age, and if designed Of sufficient size,
to carry the one ton load should be
more advantageous in every respect
* =
Motoring Department, The Herald
I am driving a 'Studebaker '-25" 1913
car SplitdOrf high tension magnetic
and start with four dry batteries and
am having trouble in keeping good
the limit for a set, and when they
drop to about u amperes they are
useless for starting I have been eau
tious about getting good ones, and
discOnnect them when not using the
car. The horn was connected with the
starting batteries, and / put IN an
extra set for it and they seem to last
the usual life Of the batteries Please
advise where the trouble is and
oblige a constant reader Of your paper.
If am not asking too much Of a favor,
kindly drop a line or two giving a
key to the trouble and you may print
this and the answer any time for the
benefit of the readers OF Motorists
Problems, emitting my Nance. J. B.
The dry cells should certainly give
you better service. Would suggest that
you use five cells instead Of four. 1t
is possible that you have these dry {
cells installed in a metal box. If so. |
any one Of the terminals may short !
circuit and cause the trouble. Like /
wise, if there are any tools or other I
metal parts in the box, care should be /
81 T--H 4. r.T-- % Tn
stalatiOn of the cells and short circuit I
them. The box in which the cells are ]
placed should be absolutely dry and !
free from moisture. If the covers OF |
the cells become damp they. viii short |
circuit A careful inspection should 1
also be made of the two lead wires I
which go out of the box. 1t is pos !
sible that one of these wires is 4
grounding at some point. There is /
also a possibility Of trouble in the 1
switch on the coil box If the switch !
lever is loose or if there is much Iost 1
motion at this point, the lever will be /
in the off position apparently but /
will not have opened the circuit. A 1
careful inspection Of all these parts OF /
the wiring should be made, since it 4
is evident that there is a short circuit /
somewhere.
Motoring Department, The Herald
In looking over several makes Of cars
with a view possibly Of purchasing
certain salesman laid emphasis on the I
fact that his car was equipped I
with roller bearings He
laid particular emphasis on this point,
and since a. number of other cars sell
ing at higher prices are not equipped
with these roller bearings am curious
TO know wherein the advantage lies.
Would like very. much to have you
answer this in the next issue Of your Z
cOlumn.-Student
Opinions Of prominent mechanical /
engineers differ as to which type of
bearing is best for use in the automo- (
bile. The make bearing used, together
with its proper design for the work
It is to do determines its efficiency.