The Chickasha daily express. (Chickasha, Indian Territory [Okla.]) 1899-current, 1901-04-26
GOOD Roads R5tss


factors tndl nave 10 do win the
advance of a community ia wealth 1t
is extravagant 20 build road with a
surface costly enough for heavy haul-
ing, but with grades too steep for any
but me fighter fUaJfs. O. iifsir11ioH4asss-
70 economize. So il is worth while 10
seek Tor harmony between the grade
and surface Of a road In this inquiry /
hair-splitting accuracy, which interests |
nobody bur the theorist. viii be avoid /
ed. And. as becomes serious men in 4
considering an important subject. no /
greater accuracy viii be INDUCED In /
than has 20 do with dollars and cents. |
How hard a pull a horse should deliver |
to his traces depends on the horse him
self. on the speed. and on the length Of
time he works For heavy hauling the
speed must, Of course. be a moderate
walk. The average horse in this south
ern country cannot deliver a pull Of
more than ninety pounds to his traces
for any considerable time even at a
walk without hurtful over exertion
Thus $50 pounds is quite as much Of a
pun as should regularly be required
OF an ordinary pair Of horses in the
South. But it must be noticed that
this is the pull on the traces and not
the weight Of the load
Next it must be observed that the
pun needed to draw a given load de-
pends on the grade and on the road
way: for we shall tacltly ascribe TO the
Ha 4sel
sources. The roadway always opposes
the motion. whether up hill. down nil
or on a level. with force Of so many
pounds per ton Of gross load hauled
The amount of pun thus exacted de-
pends on the character and condition
Of the roadway. Practically it is not
affected by any ordinary grades. While
ascending the horses must exert the
pulls called for by both roadway and
grade. Thus. a sand roadway calls for
400 pounds per ton, while steel calls
for ten. 4 twenty per cent grade
calls for 392 pounds. Hence the pull
needed to draw one ton up such
grade is 1872 bounds on sand but 402
on steel. In the same way it may be
seen that pulls of AGO and seventy
pounds. respectively. are needed in as
cending a three per cent grade on
sand and steel
Now notice what these figures mean
On level a horse can draw forty
times as much on steel as on sand; on
a three per cent grade less thar seven
times as much; on a nine per cent.
grade about three times: while on n
twenty per cent grade barely two
times as much. If we compare steel
with macadam we shall see that on a
level horse can draw six times as
much on steel as on macadam: on a
three per cent grade one and three
fourth times as much. while on nine
per cent grade only one and one
fourth as much. Thus a road Of high
class has little advantage over one OF
lower class II the grades are heavy.
AS already pointed out the pull Of the
team. while ascending. is divided into
two distinct parts. The part spent in
overcoming the resistance Of the road
way is entirely lost But the part that
overcomes the downward pull OF the
grade is not lost. but Is simply spent
in accumulating work for future use
p The amount Of this last per ton OF
load is a definite quantity for any
given vertical ascent. and cannot b'
increased or diminished IN any way
whatever Every bit Of It is recovered
on the descent. as we shall see. If no
e recovered too fast it an goes to reliev
! ing the team III recovered too fas
the excess is wasted by the brake. o
the team has to undo it by the add
tl0nal work Of holding back. In thu
5 descent the grade pulls forward an'
i the roadway holds back with tn
/. amounts per ton Of load already point
ed out SO long as the pull Of tn
grade does not exceed the reslstanc
: Of the roadway there is no waste. Tn
:. team pulls with a force equal 70 tn
e difference and gets more or less OF re
!, lief at every step. But when tn
grade pulls harder than just enough {
overcome the resistance Of the road
E way the brake must be used or th
+ team must hold back and waste r'
J. suits. This shows that there shoul
be a definite limit. different for eac
kind Of roadway. 20 the steepness Of
grade. Thus for sand. which offers
resistance Of 400 pounds per ton,
twenty per cent grade which pull
l- with 392 pounds. is somewhat belo'
Is the limit. But such a grade on stee
which only opposes ten pounds, woul
give an excess Of 32s pounds 70 !
y wasted by the brake. One-half Of on
$ per cent. is the limit for the grade @
d. steel. Extending the examination
,i the other roadways we see that
avoid waste on the descent no grad
should be sleeper than twenty laboui
o. nine. three on one-half per cent. r
De- spectively. on sand. dirt macadam
- steel roadway. Itnow remains TO 81
whether conditions connected with q
70 ascent demand the lowering Of thei
r. limits In the frst inquiry we had 4
IN guidance the well-kDown facts fro
Il mechanics and figures from the dyn
a.. 4NIa annnwa fnr4rfl