RA\ILWA.YS,
AND THE
WH EELS WHICH RUN UPON THEMI
BEING A BRIEF ENQUIRY  INTO THE RELATIVE COST in MATERIAL, OF
RAILS AND TIRES,
CAUSED BY MERE Abrasion, TOGETHER WITH THAT OF THE LATTER. CAUSED
BY waste IN TURNING, TO RESTORE THE stat' pu0o.
Also, some Remarks on the reduced TRACTIVE power required, consequent upon the introduction of
KRUPP'S CAST STEEL RAILS AND TIES.
By THOMAS PROSSER5, C. E.
NEW  YORK:
E. S. DODGE & CO., PRINTERS AND STATIONERS, 84 JOHN STREET.
1865.








WIHfI CH JRU FewN U PO 0N T T-IE~I:
BEING A BRIEF ENQUIRY  INTO THE REiLATIVE COST in2 MATERIAL, OF
RAILS AND TIRIES, CAUSED BY MEE Abrasion, TOGETHER
WITH THAT OF THE LA-TTER, CAUSED BY wasi8e IN
TURTNING. TO RESTORE THE Stlta(  quo.
Also, some Remarks on the reduced TRACTIVE power required, consequent
upon the introduction of
K ILTP9S  C AST  STEEL  R.AILS  ANDl TIRES.
BY THOMAS PROSSE-R, C. E.
TwNrTY years after the pioneer Railway had gone into operation, a
very clever itinerant Lecturer wrote thus:
"It was only lately, however, that the question was raised, whether
the rolling stock was really in the condition here described analagous to
the permanent way, and whether there is, in fact, incidental to it, the
insensible deterioration not made up by the regular annual repairs and
replacement of worn-out stock?" —Lardner's R~ailway Econonmy, London, p.
106. Done into plain English, this means, that railway engineers, just
before 1850, did not know for certain that a locomotive would ever wear
out, and require to be replaced by a new one.
It is very easy, and therefore common, for people who are typoyraphically inclined, to place practical men (who are not generally afflicted with
that complaint) in a false and ridiculous position, for the purpose of
showing off their own sagacity, by such silly remarks of a mere empiricist.




2
Of the same class are those who have been telling us, with the most
laughable superciliousness, during the last quarter of a century, that the
steacm engine is in its infancy: a vigorous young Hercules they admit, which
has, so far, strangled all the serpents, in the shape of gas and water
burners, and caloric engines, ad in.finitum, which were intended to destroy
it,-but still —an infant, and it don't appear to grow, but remains the same
as it was in the time of Watt, (if even that is not paying it too high a compliment,) when, a bushel of wheat, ground and dressed in an hour, with
eight pounds of coal, was one horse power.  And no improvement (so
called) has equalled that up to the present hour. A mere theoretical
compilation may be a very useful and valuable production, provided it
has practical experience for its foutndation, and as this can only be obtained from experts, an author does not improve his own claim to sagacity
by impugning that of such acute observers as our railway engineers must,
for the most part, necessarily be.
The significance of these prefatory remarks may better appear,
when, in after years, some empiricist makes the discovery, that' it was
only lately, however, that the question was raised, whether'steel was applicable for
the axles and tires of locomotives and for rails?'"  And, with the same selfcomplaisancy, we shall probably be informed, that "' its application to railroad purposes generally is' in its infancy /' "  But what are the facts?
Engineers and steel manufacturers well knew, many years ago, that steel
was applicable to all the purposes to which it is now applied, and to
many more, as is sufficiently attested by the innumerable patents which
have appeared in all parts of the world where they are known.
All the patented inventions, aiming at the making of steel suitable
for the purposes referred to, have been failures, for they have not produced that peculiar metal which we now know, and ought long ago to have
surmised (as some probably did) from the slightest reflection, is absolutely
essential to success.
Comparatively pure iron, as well as the mildest kind of steel cast
(not made by cementation) are equally unsuitable, on account of being
too soft, or at least wamtting in stability.  On the other hand, steel made
by cementation, if not hard is always comparatively brittle. These are
not new ideas, but such as should long ago have suggested the peculiarity required in the metal to make it suitable for these purposes, viz.:
the toughness of the softest steel, with the stability of the hardest qualities,
and combined with the most perfect homogeneousness.   Whatever
influence the price may have had in retarding its introduction, we are




3
quite sure, now, that doubling it will not prevent its use by those who
know its economic value. Besides this, the large masses of 40 tons of
cast steel in one ingot, were never dreamed of, or if they were, the
dreamer kept very quiet about it, probably thinking it too absurd to be
worth mentioning.
Nevertheless the public history of large ingots of cast steel commenced with the Great Exhibition in London, 1851, when Mr. Krupp
exhibited one weighing 4,500 lbs., the heaviest until then ever known,
and led the jury to award him the only Council Medal granted to that
class. In 1862, also, at the London Exhibition, he again exhibited an
ingot which astonished every one, and distanced all competitors. That
ingot weighed 20 tons, being limited only by the difficulties of transporta.
tion, time and space allotted. It will not do, therefore, to assign any
limits to the weight of these ingots in future, seeing that they are already
required and furnished of 40 tons weight, and probably may yet be
required of 100 tons, and will as surely be furnished.
The London T]imes says of Mr. Krupp's Exhibition of 1862:
" We now arrive at the consideration of one of the most extraordinary and most important collections in the Exhibition, the like of which
has never previously been witnessed; we allude to the truly magnificent
display of Krupp's cast steel. The special points of interest are the
wonderful soundness and the enormous size of the castings; and in these
respects he is so far in advance of all other producers of cast steel that it
will be extremely difficult to approach, much more to overtake him
"The largest casting exhibited by Krupp in 1851 weighed 2+ tons,
and the largest in the present exhibition weighs 21 tons. It is in the
form of a solid cylinder, about 9 ft. high, and 3 ft. 8 in. in diameter. It
has been broken across to show fracture. We have inspected the fractured surface over and over again, even under a good lens, and we have
failed to detect a single flaw.
"We notice drawings of locomotive axles supplied to some of our
largest railway companies, and crank axles of marine engines supplied
to some of our most celebrated marine engine makers. We congratulate
Krupp on the pre-emiient position which he occupies in the world as the
producer of the largest and soundest castings in steel."
REMARKS.- The "largest and soundest" without " a single flaw,"
is the ultima thule of the steel maker's hopes, and bearing upon thesepoints a very significant compliment is paid to the Krupp cast steel, in




4
several Patents, claiming to be for improvements in the manufacture of
all others, including Bessemer's, by which they are to be made "' homogeneous" and "free from flaws."
Manufacturers saw at once that it was no ordinary cast steel which
was then exhibited, but they did not know that the large cannon which
they saw  before them, possessed a greater specific gravity than is
recorded of any cast steel ever before produced
The consequences of this are not fully known, but there can be no doubt
that, the causes which produce it, are also mainly instrumental in producing the extraordinary stability and resilience of Krupp's peculiar cast
steel, which no other cast steel possesses.  "Resilience" is a term
first applied by Dr. Young, to represent "strength and toughness conjointly;" he also defines it as, "the power of overcoming the energy or
impetus of a body in motion."  The term is a very comprehensive one,
and is entitled to much more attention than it has usually received.
There are, however, many difficulties in the way of assigning the
modulus of resilience, so as to compare with metals so impure as cast
and wrought iron. It should seem that, the greatest possible " resilience"
is obtained, by any metal, when the modulus of elasticity is the same for
compression as for extension,-and it may be, therefore, that the
increased density of Zrupp's cast steel over all other, produces that equilibrium therein, which we have supposed to be essential to the highest
state of resilience (or perfection) of which it is capable.
The distinction here made, between compression and, extension, is
too often ignored, and both are represented by one modulus, when we
know, that the ultimate disintegration of the molecular structure of all
the metals, is accomplished by very different amounts of force, according
as it is applied to compression or extension;-thus, copper is crushed by
a force equal to one-fifth of its ultimate cohesion, and wrought iron by
one-half; while cast iron requires about 6.5 times on the average, varying from about 4.5 to 8.5 times. According to the experiments of Eaton
Hiodgkinson, in the Blue Book/c-" Application of Iron to Railway Structures," 1849. The difference in the specific gravity of cast iron amounts
to 5 per cent., varying from 7.181 to 6,839, i. e. one cubic foot will vary
from another 342 oz.,=-271bs. 6oz. in weight,- (448.8125-427.4375) lbs
The crushing force varies from 120,493 to 55,298 lbs. per square inch;
while the tensile strength is from 25,775 to 11,059, and even in the same




cast iron from 25,775 to 20,150 lbs. per square inch. These facts are
commended to young Engineers, who put their trust in tables. The oldfashioned rule, therefore, of calculating the reliable strength of materials
from their ultimate disintegration, is evidently wrong, and scarcely fit
even for a rule of thtmb. The modern method of calculation by the
modulus of elasticity is doubtless better, but the imperfections of cast
and wrought iron, and their entire want of homogeneousness, renders
any calculation as to the amount of compression or extension which they
will bear with safety, altogether unreliable.
These remarks will be fully vindicated hereafter, when we come to
contrast the absolute homogeneousness and integrity of Krupp's cast steel tires,
viewed under the sagme circumstances as cause iron ones to exhibit an
entire want of both qualities, for, while the latter will sometimes almost
rival the former during a short period of their service, they invariably
give out long before them. And still more, it is no exaggeration to say,
that iron tires of the same make and performing the same service, will
sometimes run but one-fourth the distance which others will performsuch is the uncertainty of iron tires, as is well known to practical men.
That the rails are subject to the same uncertain durability is equally
notorious.  How, inde~ea ai] be otherwise?  So long as action and
re-action are equal, and cause and effect are equally reciprocal, there
must be a ratio between the abrasion of the tire and the rail.  Nevertheless, inasmuch as this ratio depends upon an almost innumerable variety
of circumstances, we may not expect any great amount of accuracy in our
endeavors to develop it; for instance, if the tire is very hard and not a
true circle (which is invariably the case with chilled wheels) we have a
hammer, perpetually at work upon the rail to destroy it. Wrought iron
tires, although equally untrue after a little wear, will hammer it less
destructively (because softer) whatever may be the effect upon itself.
At the same time it is self-evident, that perfect circularity in both kinds
of tires, must result alike in saving both tires and rails.
It has been said (however absurdly) that the wear of tires and that
of rails are complemental to each other; in other words, that the tire
which is worn the least will wear the rail the most, so that the aggregate
of the two will be equal. This dictum, which has not the shadow of
proof or reason to support it, appears to have been brought forward by
the iron men, to save the iron rail from following the inevitable doom of
iron tires into past history. Chilled wheels undoubtedly batter away the
rails more than wrought iron ones, for the reasons before given, none of




which apply to Krupps' cast steel ones.  Both tires and rails of Krupp's
cast steel long retain the shape originally given to them, in virtue of
their stability or resistance to a crushing force, while their toughness is
a guaranty against excessive grinding, and their molecular structure
against lamination. It will be shown, that an ordinary wrought iron tire
lost by wear 14 oz., while one of Krupp's cast steel lost but 4 oz., under
precisely the same circumstances. Does any one believe, that, while the
former actually ground the rail 86 oz., or 6~ times its own wear, the
latter could, by any possibility, have ground the rail 96 oz., for,
(14+86)=-(4-1-96), or 24 times as much as its own wear?  No; it is
impossible,-for, with tires maintaining their perfect circularity, and rails
equally with them perfectly homogeneous, the reaction of the tires upon
the rails and the road bed in one direction, and upon the rolling stock
(including the locomotive) in the other, must be reduced to a minimum;
and hence it cannot be too strongly insisted upon, as of the highest
importance, that all the wheels of a train shall have such tires, thereby
reducing also the tractive power required, and, of course, the weight
necessary upon the cdrivers.
The loss, by wear, of rails and tires, by mere abrasion, is very small,
as compared with the mass. A track of1 -— Iawll require 1,000 tons
of iron, with rails of 63 lbs. to the yard; 400 tons passing over this track
60,000 times will abrade from the rails 17 tons, or 1.7 per cent. of the
mass, but the rail will be used up, or at least require to be replaced,
from some cause or other. That cause is not the mere abrasion, but the
disintegration of the mass, caused by the severity of the service, and the
increase of that mass affords no remedy to the evil, which is want of
stability; the material is overtaxed.  An iron wheel, carrying 100 lbs.,
may be run upon an iron rail for a long time without any perceptible
wear to either, but, place 100 tons upon the wheel, and the destruction
of both rail and wheel tire in a very short time, is inevitable.
Theoretically, the whole weight rests upon a point, but, practically,
we know that there is compression, and if that compression is in the least
degree permanent, deterioration has set in, and the substitution of a
material having greater stability is the only remedy. The data for carrying out this part of the subject is very meagre, but that is no excuse for
not using such as we have to the best advantage, and the more so,
because of its immense importance to life and property. In doing this
we shall develope some curious anomalies, while laying the foundation
or more correct investigation hereafter.




7
The Belgium Engineer, M. Belpaire, has determined the life of the
rail to be 120 years, with 3,000 trains passing over it per annum, or
360,000 trains altogether.-" Lardner's Railway Econonmy," London, page 49.
Capt. fuish, of England, makes it 20 years, with 18,250 trains per annum,
or 365,000 trains altogether.-Ibid, p. 51. As the calculations were
made on totally different principles, they are singularly confirmatory of
each other, apparently it may be, for we are not informed of the weight of
the trains. The Belgium rails were of English manufacture, 55.5 lbs. to
the yard, while the English rails were 70 lbs. to the yard on the average.
The velocities and weights of the trains is assumed to have been proportionately greater on the English than on the Belgium lines, " so that the
coincidence of the conclusions is not disturbed by this difference," says
our author.-Ibid, p. 52. It must be admitted that this is rather loose
generalization; however, we have to make the best of it, and hope to have
better information hereafter, when the want of it is known and properly
appreciated. It appears, furthermore, from  the experiments of M.
Belpaire — Ibid, pp. 49, 50,-that a 25 ton engine passing over nearly 61
miles, abrades from the rails 2.2 lbs., or 36 lbs. per thousand miles.
The average life of the best iron tires may be 60,000 miles, during
which time four of them will grind up one ton of rails. The tires themselves will lose on the average about half as much as the rails, or half-aton, when they will be worn out, supposing them to have been turned
twice and run three times. Of this half ton, not more than 7.217 lbs.
per thousand miles is calculated to be due to mere abrasion, or about
one-fifth as much as that from the rails. This, however, is but an
approximation, for the uncertainty inherent in the nature of the material,
as well as the service it is subjected to, renders anything like accuracy
impossible.
]Mr. Adams, of the North London Railway, calculates the average
life of Krupp's tires, on that severe line, at 189,539 miles, and of Low
Moor at 30,531 miles; or, as 6.2 to 1, on coupled driving wheels. But
Krupp's had lost but 2// of metal on the average of 21 engines, while the
Low Moor had lost "//. In other words,  rupp'8s cast steel tires ran
94,770 miles, and the Low Moor 8,723 miles for each 4 "of metal lost;
or, as 10,864 to 1, and there is no reason known why Krupp'z s tire should
not be reduced, the same as the iron ones, by -," or even more.
On the Chemin de fer de Luxembourg (France) Krrupj's tires ran
65,774 kilometres (40,871 miles,) with but 6ths the loss by abrasion
alone, of a puddled, or semi-steel one, which ran but 18,640 kilomftres




8
(11,582 miles) or, as 1 to 4.117.  And I am permitted to say, on
authority second to none, that 4 of an inch of a Krupp's east steel tire,
will outwear any thickness of iron tire.
The great defect of puddled steel, is the uncertainty of its quality,
equally with iron, the interior of which latter is usually soft and does:
not wear as well after turning as before, and hence has arisen the vicious
practice of using them without turning at all; this gives a fictitious value
in their early use, for which the rails, the rail bed and the rolling stock
has to suffer, in consequence of the imperfect circularity of the tires, which
also absorbs the power of the engine to overcome it. Jrupp's cast steel
tires, on the contrary, suffer no deterioration whatever in the quality of
the metal exposed to wear by turning away, while iron ones are usually
considered to be half worn out, whatever their thickness, when they
require turning after the first running.
The obsolete idea of flexible tires, has recently again been revived,.
but somewhat moderated in its ramifications, still, in any form, it must
be a rail-pounding power-devouring device, which is about as rational as
any other contrivance to be always going u p-hill, when a level road is
equally available. Still, if there be any economy in their use, it must at
least apply, pro rata, to steel as well as to iron tires. It is one of those
contrivances which, like hollow axles, reappears about every decade as
an epidemic.
The most perfect rigidity is required in the beds of all running
machines, and it would be strange indeed if railways formed an exception. Rails have been laid with a continuous support on granite blockse
but as the wheels were subject to flat places, at every one of which the
superincumbent weight came down upon it like a hammer; it was the
same as setting an anvil upon granite instead of wood, the effect of which
reacts upon the smith's arm, and soon compels him to desist from working upon it. Let us go back to first principles, by removing the wheels
of a car and running it as a sled upon the rails; the parts in contact.
shall be perfectly hard, straight, level and smooth, and, moreover, be
well lubricated;-do you not want everything as rigid as possible under
the rail, just the same as under the ways of a planing machine? Now,
what are wheels for, but to transfer these hard and smooth surfaces to
their centres, or nearly so, to a circular form, which is easily made
almost perfect, while the oiling can be done effectually and all dirt and
grit be excluded, all of which are impracticable with a sled. Stop the
hammering of the wheels upon the rails and a rigid road bed becomes




9
truly economical, by reducing the power required in the locomotive to
draw the load, and, of course, the weight required upon the wheels, as
well as the wear and tear of everything connected with the rolling stock,
rails and road bed'
It is not at all wonderful that chilled wheels hammer the life
out of a rail in 3 or 4 years, which should last at least 20 under fair
treatment. We learn from  Mr. Winslow  (ML. M. of the ilousatonic
Railway,) that the " Reindeer," weighing 45,054 lbs., ran 72,483 miles,
with an average wear by abrasion of -136/, on a set of 4 of Xrupp's east
steel tires. These wheel tires, which were 57.75 in diameter when they
commenced running, were 57.375 in. diameter when they had run these
72,483 miles; the average width of the wear of each tire was 2-, which
gives 871bs.== —1.49 lb. per thousand miles for a 25 ton engine, as the
amount of wear by abrasiyn only. The wear by abrasion of the puddled
steel tires on the Luxemburg, we have seen, was 4.117 times as much as
KrupAp's cast steel ones, and we are quite certain that iron ones wear
much more. HIence we assign 358 lbs. for loss of metal by mere abrasion
of puddled steel tires in running 60,000 miles,=6.14 lbs. per 1,000 miles
with a 25 ton 4-wheel locomotive, while a former statement makes the
loss of iron tires=7.21 7 lbs. for the same service. The amount of metal,
however, which is abraded, is of little importance compared with the
actual life of the rail and tire. But, we must now abandon the idea of
there being any assignable ratio between them, at least in this country,
for the thickness of tires is everywhere being increased, to such an extent
as probably to double the life of the Krteup's tires on the heavy working
roads, without prolonging that of iron tires at all, for, on some lines,
where iron tires have been used 3 inches thick, they-are not considered
safe when reduced to 2 inches. We can arrive at no other conclusion
than this; the life of the rail is prolonged inversely as the abrasion of the tire.
If, now, we substitute for the iron rails, a quality of steel ones equal to
the steel tires, is it not clear that the tires will be worn less in consequence thereof? If both were infinitely hard, they would not wear away
at all. In pulverizing a hard substance with pestle and mortar, the
latter will be abraded the same by the same service, of whatever substance the pestle may be.
The grinding of rails and tires is greatly increased by the dirt and
grit which gets in between the lamina and into the pores of iron, but
which cannot penetrate into ATrupp's cast steel, for it is ground by it to
an impalpable powder, with but little injury to itself.




10
It has been said by some of the iron men, that the adhesion, or bite of
the tire upon the rail will be greatly reduced by substituting steel for iron.
Surely it required no " spirits from the vasty deep" to tell us that.  If
there is no grist in the mill, there will be no grinding done. Regarding
the weight on the driving wheels of a locomotive, and their consequent
adhesion to the rail as a point d'appui, it does not necessarily follow, that,
because we reduce the grinding propensity we reduce the usefcl adhesion
pro rata; but it does necessaril, follow, that we save all the motive power
necessary to perform the extra grinding. There, in fact, lies the whole
gist of the thing. Reduce the grinding, and you reduce the tractive power
necessary to perform it and in the same ratio, and you save, too, the
machinery, rolling stock, rails and road bed; and if the rails are perfectly level, the wheel tires perfectly cylindrical, and both infinitely hard,
with no friction on the journals of the axles, a bird may fly away with a
train after the vis inertia is overcome, but for the resistance of the atmosphere. A-propos of axles; let any one examine the journals of iron
ones, and then those of Krupp's cast steel, with a powerful lens, and the
cause of the reduced friction of the latter, as well as the lesser quantity
of oil required for lubrication will be apparent enough.  An iron axle,
running 70,000 miles in 2 years, is unsafe for further use; but one of
Klrupp's may be run for 50 years, or even more, according to present
experience, for not one has ever been known to wear out. They have
indeed run 80,000 miles without showing any appreciable wear, and the
oil required is reduced to one-half of that required for iron.  The best
test is the fracture, which at once discloses the cause-of the greater
density of Iurzpp's over all other cast steels, viz.: the fineness of the
grain, or crystalization, and also that of its unapproachable toughness,
and hence its greater resilience and immutability to fracture, which any
tire, and particularly cast steel ones, are subject to after being worn
thin.
The following table [No. 1.] comprises the most important features
of the foregoing observations, in regard to the cost in material, caused
by the running of a 25 ton 4-wheel locomotive 1,000 miles.




11
TABLE No. 1.
i |.           Total loss by
COST IN WEIGHT OF METAL BY ABRAL'ION.               abrasion and
turning.
Rails & Tires Rails. Tires.  Tires.
To run a 2b ton Four Wheel Locomotive one
thousand miles.              Ratios.
ii                              4~~~~~~~~~Ratios.     Lbs   Lbs.   Lbs.
Iron Rails and Iron Tires..............  100. to 20.  36.  7.217   18.3
Iron Rails and Krupp's Cast Steel Tires..... 100. to 41.  36.  1.49  2.65
The rails are put down for " abrasion" the same, whether iron or
cast steel tires are used, because there is really no data on that subject.
It is however impossible that such should be the case, for there is no
doubt that at least half the destruction of iron rails and tires is due to
the hammering force in the inequalities in the iron tires. This matter
has been considered before in answer to the statement recently put forth,
that the aggregate wear of the rails and tires is a constant quantity, and
it was shown that inasmuch as 14 oz. of iron tires had ground up  86 oz.
of iron rails, the 4 oz. of cast steel tires which had been abraded off by
the same service, must have ground up 96 oz. of iron rails, or 24 times
its own wear.  If we apply this principle to the table [No. 1,] we shall
have to make the cast steel tire grind up 29 times its own wear of the
iron rails, for 29  ((31-42 ).  Instead of this result, it is confidently
predicted, that the ratio of wear by abrasion between steel and steel, will
be restored to the same as is obtained between iron and iron, for the
difference in material has no effect upon the immutable law, that action
and reaction are eaqual.  If, therefore, the life of the tire is prolonged
4.84O6- -727) times, by the substitution of cast steel for iron, there
seems no good reason to doubt, that the same result will be obtained in
regard to the life of the rail being increased in the same proportion by
the same means, and therefore, if both are of cast steel, we may safely
presume that the life of both will be increased by at least the half of the
square of the previous increase, for, although we have assumed that there
is perfect reciprocity in the cases, whether of rails or tires, as to the substitution of cast steel for iron, it does not apply to the substitution of cast
steel rails, so far as to benefit the iron tires, because half the cause of the
deterioration of both arises from the hammering of the tire upon the
rail, which is not effected thereby, we therefore derive but half the
benefit.  Thus, 11.73= —(i, 4.84262) represents the increased life of the




12
rail and tires by substituting cast steel for iron.  When, however, the
rails are supported on granite blocks not more than 20 inches from
centre to centre, and going down into the earth to a good foundation,
below the penetrability of- frost, with perfect drainage, and the ways as
rigid as those of a planing machine, I have no doubt that both rails and
tires of cast steel will wear quite 20 times as long as iron ones now do,
that is to say, they will do 20 times the effective work with the same
wear.  The effective work done is the passengers and merchandize
carried, the weight of which is fixed, but the vehicles for performing that
service, including the locomotive may be greatly reduced: and so also of
the tractive power required, and therefore the weight on the driving
wheels, and consequently that of the rails.  Under all the circumstances
of the case, this estimate is a very moderate one, and will doubtless some
day be fully realized, as defined by Era, 4, in table [No. 2]; Era, 3, is
in course of development, while Era, 2, is present, and Era, 1, belongs to
the past.
TABLE No. 2.
_........                _
COST IN WEIGHT OF METAL BY ABRASION.
lKails and Tires,.  Bails.   Tires.
I.     To run a 25 ton Four Wheel Locomotive
one thousand miles.
Ratios.  i Lbs.    Lbs.
i / ---  0-    _ __ ------- ~ —-------    [,- --------    - _____________
Era 1, Iron Rails and Iron Tires.....       100 to 20   36.      7.217
"2,' "    Krupp's C. S. Tires...........................49
" 3.  S. Rails, and''~ now..  100 to 20    3.068     607
i" 4,  "'  ". ". hereafterl   "  "               1.8.36
4,l Ratio to Era...............               100   1.8       36
3.............. now. 8.5 "100  3.068 i.607
The conclusion arrived at by table No 1 is, that one of Arupp's
ca'st steel ftires, will outwear seven iron ones, upon an iron rail, with the
same loss of metal by abrasion and turning, [18.3-:-2.65].  But, if both
are of the same thickness when new, the cast steel tire may be turned
down, so much thinner than the iron one, as to outwear at the least ten
iron ones.  While, by table ANo. 2, upon steel rails, with all the running
tires of Ilrzyp's cast steel, the life of both may be calculated upon being
prolonged 20 times,=[3S-:-1.8]-=7.2 17-:-.36], as compared with iron
rails and iron tires.  And finally, Krupp's cast steel, when it has yielded
all the service it is capable of as rail, tire or axle, requires only to be
drawn out under the steam hammer to become again as available and
as valuable for other purposes, weight for weight, as it was originally.
NEW YORK, October 20, 1865.