Weekly national intelligencer., 1851-08-09

inches and the latter Of 20 inches diaeerthe length Of
stroke in each case being ~ inches On the previous day
~ with eighteen cars 20s and 3a4 respectively, and
each drew its load up the grade without hang slipping its
wheels, and at speeds Of from dix eight miles per hour
The Of nsction Of the two engines with equal pres
ures steam. should be nine for No. n to for No.
(which numbers show the proportional Of their cy
inde which have the same roke-her wheels being also
OF the diameter Of foyhree inches For every nine
cars that No. III would draw there should then be
drawn BY No. ~. The adhesion however, Of the engines
is in different rao that Of No. III being represented the
number that Of No 70 will be- by the number 66-l00.
Engine No. ~ has therefore, the adhesion in proper
ton to Its scve power and II both are using ell their sd
heson, engine No. ~ will do With slightly less pressure
Of steam. lssSN a6 H@
per ton of 224O lbs, Of which 40 $40 L due gravity,
lbs to friction, and ITO lbs to curvature Of 1000 fee.
radiusthe shortest which upon the grade Of lie feet
per mile This 10 the maximum resistance met with any
where this grade Where Of 600 feet radius occur
the grade reduced coespondingy Engine III weighing
"a TONS lis tender about l6 TONS and It's load 2Os tons
making 24s In a-the tractve power required was
Is 60 bs, exclusive Of that necessary to overcome the
sstance Of the engine within itself The weight Of the engine
being 53 760 b the part Of its weight expressing the ad-
heson Of s wheels to the rails was therefore $685. BY
the principles Of calculation We make the ractvs power
Of engine ~ l6, $50 bs, It, weight being 25a TONS
its tender say l64 tons and s load 234 tonshe whole
equal 276 The weight Of the engine being 81 $50
lbs, the part expressing is adhesion would be 3-42.
These ratios show high degrees Of adhesion but they are
such may be expected prevail when the rails their
best condition although In the daily work Of the engines,
they would not be required 70 work up nearly the lim,
Of their power
In the calculations BY which the performance on these
grades estimated power and adhesion was assumed
but little exceeding onehaf Of those exhibited th
occasion. tf
Inasmuch by the uss Of nnd upon the rail when il
slippery from frost other cause adhesion Of 5 or
more, be commanded il win be concluded that in work
ing this grade practical difficulty will be found any
With adhesion Of l-6 only, engine II would draw
| l0s, and engine ~ ll8 tons behind the tender.
These loads would be 10 and loaded double cars the
ordinary weight Of about TONS and with them speed Of
least 10 miles per hour could easily bs maintained
Il is observed that the speed Of engine H. with the passen-
ger train, miles per hour the grade This with
load Of tons. equivalent weight about twice that Of
ordinary trains Of that descpon which do often exceed
go tons. a
There can be doubt them that engines Of that class
which will probably be used for passengers upon this gade
will ascend them, without assistance, with such trains.
It is deemed unnecessary to say respecting the per-
fomance Of the engines than that they and their trains de-
grade speed Of 10 TO Is miles per hour under
the control Of the brakes and might safely have run down
considerably faster had il been desired ss R3f