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West, the best part of the spring travel would generally be over by the time lake Erie was free from ice. It is true, that in '38, the difference between the two routes would have been trifling; but in '37, the difference would have been more than two months! This extreme uncertainty of the route by Buffalo, is its worst feature. At the present time, (18th March,) the navigation has been open 2 weeks from Detroit to Cleavland, and, if westerly gales do not prevail, it may, in a few days, be free to Buffalo, otherwise it may, as in '37, be closed till June. In this state of things, many of the western traders would come to the city before the opening of lake Erie, (in ordinary years,) and not unfrequently return before that event, by means of the Great Western railway, and a considerable portion of the present spring travel by lake Erie would be over, before winter would permit the steamboats of the lake to enter into competition with the steam-car of the Great Western railway.

To form a perfect communication throughout the year, would require a railway 45 miles in length, from the falls to Hamilton, and from Chatham, or wherever the western terminus might be, to Detroit. When the roads are in their worst state, the navigation at Detroit is nearly always open, and steamboats can ply on Ontario nearly all winter. In the most possible event it would only delay the traveller a single day and he would reach New York in 3 days, instead of, as now, occupying from 10 to 14 days incessant travelling round lake Erie to Cleaveland, and thence through Philadelphia to New York. These two railways, connecting the termini of the Great Western railway with Buffalo and Detroit, would be used by a comparatively small number of travellers during the winter, and very little during the principal travelling season, hence it would be, in every point of view, injudicious in the Great Western railway to extend itself beyond what is absolutely necessary to give it a decided advantage over the route by ke Erie. Great thoroughfares, only, will justify the construction of large works in a new country, and the vast importance of reducing the length of a railway as much as possible, a subject which occupied some space in the original paper, has been, as already observed, published in this Journal. When there is no difference in distance, passengers may be carried in steamboats for much less than on railroads, and this would give a decided advantage to the boats from Chatham to Detroit, moving through smooth water, over a railway between the two points, for, at least, 9 months in the year, comprising, probably, more than nine tenths of the travel. The Camden and Amboy company, owning both railway and steamboats from Bordentown to Philadelphia, use the latter during the entire season of navigation, and as this company is eminently well managed, and as this practice still continues, after seven years experience, we must admit it to be very strong evidence of the superiority of steam navigation, on rivers, over railways-when the distances are nearly equal.

"It is an important object to know the minimum amount of income nenessary to repair and renew the road and pay interest on the capital."—

This subject was examined in detail, but now it will be sufficient to state that the cost of the Great Western railway may be assumed at $16,000 (4,00.. currency) per mile with everything requ site for an extensive passenger business and of course a single track. This is about the cost of the Utica and Schenectady railroad, deducting the cost of right of way, superstructure, and graduation of second track, and for 140 miles would amount to $2,240,000 (560,000) or in round numbers 600,000l. ($2,400,000.) The interest on this sum would be, at 5 per cent. $120,000, and is entirely independent of the amount of business, as will also be the repairs and renewals of roadway, to some extent. Estimating these latter at $400 per mile, and we have for repairs and renewals $56,000 and adding the interest $120,000, in all $176,000. The cost of engines, cars, buildings, etc., will be in proportion to the business, as well as the wear of the same, fuel oil and wages. To arrive at any definite statement of expenditure, it is necessary to assume a certain number of travelers, and supposing these to be 50,000 per annum, and that the cost of transportation, exclusive of interest and repairs of road, is one cent per passenger per mile, we have $70,000, which added to $176,000 gives $246,000 (61,5007.) per annum. as the minimum income required to pay interest and all expenses on the transportation of 50 000 passengers over a railroad 140 miles long, the entire capital expended being 600,000l.; or a gross income of very little more than 10 per cent. on the capital. Judging from the cost of other works in the Province, this estimate may be considered very low, but a railroad in the Lower Province has been built for much less and there can be no doubt that a railway through so easy a country, could be completed with the heavy iron rail for from $20,000 to $22,000 (5,000l. to 5,5007.) per mile, with all complete for an extensive business in passengers only.

The usual fare on railways is 4 cents per mile or $5,60 for 140 miles, but assuming only $5 as the charge and the income from 50,000 passengers would be $250,000. A though $250,000 be but a small part of the sum paid by passengers on lake Erie, some years will elapse before the country through which the road passes will furnish that amount of business, yet this is indispensable if the work be expected to support itself. That the western travel alone exists to a far greater extent than this is well known, and whether the reasons given in this paper for supposing that the Great Western railroad will be able to divert to itself a large proportion of the travel on like Erie, are sufficient to justify this assumption as well as to establish its claim to rank as the best route from New York to the country west of Sandusky, is respectfully and confidently submitted to the intelligent reader.

The ultimate, though not very distant prospects of this work are worthy of notice. An inspection of the map will show, that the navigable waters and artificial communications from the East convirge towards Ontario, those from the West towards lake Erie. Thus we have the St. Lawrence, the Hudson and the railway from Boston to Albany to bring the traffic of the

country bounded by the St. Lawrance, the ocean and the State of New York to Ontario, and on the other side, the Maumee canal and the Detroit, and St. Joseph's railroad both point to the western end of lake Erie. The completion of these two works may be lo skel forward to as not very far off, now that the grind "systems" have explo led, and the construction of the Great Western railroal would do much towards hurrying on the Detroit and St. Joseph's railroal which will eventually be its most important tributary, for it will necessarily command the travel of Michigan, part of Indiana, the best part of Illinois, all Wisconsin and lowa, forming with the Can idian Peninsula, the most valuable agricultural district in N. America. Other topics, which would be uninteresting here were alluded to;— among the rest, the implicy of commencing active operations until it is certain that the amount required to pnt the road into efficient operation can be commanded, and the still worse policy of opening, in part, a road which depends principally on "through passengers" for its success; to which causes may be principally attributed the insignificant progress of the Baltimore and Ohio railroad for the last 5 or 6 years. The propriety of adopting this as a Provincial work was suggested, but, although the most important work which could be projected in either Province, the experience of Pennsylvania held out little encoragement to the cause of Government railways, even at that time, and, after the union of the Provinces, the case will be hopeless, for the French paaty will go "en masse" against the system of government works from their general dislike to innovation, and many of the other party, incluling so ne of the most influential, are strongly opposed to it oa constitutional grounds; besides which, the, with one exception, complete failure to meet their ordinary expenses, and interest-of all the State works in the Union. would, of itself, be sufficient to cause men of sound judgement to move with the utmost caution. Whether the experience of Upper Cina la proves, that the very large sums expended on internal improvements in that Province have been laid out on these works which the wants of the community most and soonest reqnire and which the means of the Province are adequate to carry through, is a question which, if answered in the affirmative, would show a state of things the reverse of what exists here, and would constitute one honest argument in favor of a policy which, its best friends must adinit, is utterly at variance with British institutions.

It is impossible, at the present time, to form any idea of the effects to be produced by the great political change about to take place in the Canadas but, whether ever completed or not, the route of the Great Western railroad offers a vantages which can never be found in any communication between New York and the West by way of like Erie. It is impossible to point out, on this continent, a work of equal magnitude, requiring only an expen liture of from 2 to 3 millions of dollars, the completion of which will be attended with such important results to the Eastern States, New York and the best part of the Western country.

The Great Western railway will offer the cheapest and quickest route, because it will be shorter than any other-the easiest, because the night will be passed in steamboats, and the earliest, because Ontario and the western part of Erie open long before the eastern. However long its completion may be delayed, it will, when completed, become, at once, the great western thoroughfare, for its advantages over any other route which can be projected, are owing to natural causes which no competition can affect, and it is not unreasonable to infer, that the opening of this very properly styled "Great Western railway," will produce as great a change in the "travel," as the opening of the Erie canal did in the "trade" of the West.

CRANK MOTION AS CONNECTED WITH DE PAMBOUR'S EXPRESSION OF THE POWERS OF LOCOMOTIVE ENGINES.-By W. McClelland Cushman, Civil Engineer.

Attempts have been made on many occasions, by different individuals, to account for the failure of de Pambour's formula by attributing the errors to loss of effect from crank motion; and this suggestion is in some degree plausible, as that gentlemen does not notice, in direct terms, the effect of the crank in modifying the force actuating the piston. It may, however, without any trouble be shown to be inadequate to account for the well established deviations of this formula. It has not indeed any degree of pertinance to such an inquiry.

These positions are easily made out. But in the first place, I will il lustrate briefly the operation of the crank in transferring the power from the piston to its working point upon the wheel, which will best be done through the medium of a diagram.

P

b

B

In the annexed sketch, B represents the piston, C the wheel worked by the crank, r the connecting rod, and d the arm or throw of the crank. The expansive force of the steam is of course exerted, reciprocally, in the direction ab. Now this force in passing from this its primitive direction to its final direction in the tangent to the rotary circle of the crank, must evidently lose two proportions-one determined by the sine of the angle included between r and ab, the other by the sine of the angle included between r and its final direction. It would be easy to express generally, in terms of these angles and of r and d the amount of power actually oper

ative upon the end of the crank at any point of its revolution; and by means of the calculas to suin the to al amount of force expended during a complete revolution. This compared with the amount of expansive force exerted upon the piston (after allowing for virtual velocity) during the same period that is a double stroke of the piston-would exhibit precisely the proportion of power lost through the intervention of the crank and its gearing. A procedure like this is conceived to be the only means of arriving, mathematically, at a true result. A theoretic investigation of this point, is, however, quite unnecessary to relieve the main question of all embarrassinent-for these reasons.

1. Because the loss of effect from crank motion will not account for the errors of the formula.

A decisive circumstance is entirely overlooked by those who rely upon this principle for this purpose. It is quite evident, that whatever may be the absolute loss from the crank, that it will be on some constant relation to the power expended on the total resistance. Unfortunately, however, the results of experience and those deduced from de Pambour's formula bear no such relation to each other. On the contrary, the two results are sometimes nearly coincident, and then deviate very widely, &c. For instance, (Railroad Journal, vol. IX, p. 45,) we have deviations from experiments of 10, 31, 18, 11, 26, 57 per cent. in one set of trials; and 35, 30. 38, 19, 5, 10, 18, &c., in others. Those, therefore, who refer the errors of the formula to the intervention of crank motion, are reduced to the dilema of explaining results which differ in every assignable degree from experience, without order or rule, upon the principle of an invariably proportionate loss; and if the formula had been constructed without any reference to crank motion, its deviations from experience would, for this reason, require some very different cause to explain them. But,

2. The suggestion is not in any degree pertinent, inasmuch as the loss of effect from crank motion is already provided for in de Pambour's formula!

This last is a palpable paradox, but a glance will suffice to render it intelligible. For let it be observed that this resistance of an unloaded engine is incorrectly named, when designated friction. It is indeed a compound result, including within it the effect of the crank and is, in fact, the friction proper to all the rubbing parts of an engine increased in the ratio of the loss from crank motion. So when an engine is tracking a train of cars, the total tractive force is made up of the friction proper to the cars and of the resistance of the engine, now still greater than when unloaded, in proportion to the degree of pressure thrown upon its rubbing parts by the train in convoy; which resistance includes, as before, the effect of crank motion.

When, then, the value of the total resistance of the engine, per ton* of

The actual loss of power from crank motion in engines of this class is always less than 6 per cent. For the friction per ton of load upon a level being 8 pounds, and the in

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