Part 5

And notwithstanding that instances of velocities equal to ten miles an hour having been attained by locomotive engines, were not very common at the time the line of the Liverpool and Manchester Railway was laid out, yet do the under-quoted extracts from various publications of the period prove, both that they _had_ been attained, and that much higher velocities were confidently anticipated: while Mr. Treasurer Booth, at page 37 of his book, says, that “the earth work (comprising the cuttings and embankings along the whole line) was not commenced till January, 1827.” {29b}

Such statements being (as it were, officially) promulgated, and such opinions entertained relative to the velocities attainable by locomotive engines:—the question as to the employment of horses being, thus, an open one, not only during the survey for the second line, but also for two years and a half after the Act for the Liverpool and Manchester Railway was obtained; and it being equally well known as it is that the sun gives light, that for the gallop which coachmen push their horses to just before touching a hill, in order to give their vehicles the momentum which imparts the “swing that carries their horses up the hill”, rates of 15 or 16 miles an hour could be attained—it being thus known at the time the line of the Liverpool and Manchester Railway was laid out, that average velocities of 10, and occasional velocities of 15 miles an hour could be attained: and it being unquestionable that if friction be counteracted (as it is by the continuance of the operation of the moving power) the momenta imparted by those velocities will carry any vehicle up any inclined plane to the heights of 3⅓ and 7½ feet, it was necessary only to have laid out the railway in short levels, with sharp inclined planes rising a foot or two between them, to have avoided all deep cutting or high embanking.

It is true that owing to velocities of ten miles an hour, having at that time, been only occasionally attained by locomotive engines, it might have been proper to keep these ranges of levels, and inclined planes _within_ the limit prescribed by that rate. But as this limit is not within a vertical rise of 3 feet 4 inches, it would have been perfectly possible, by arranging short levels with sharp inclined planes of three feet in height between them, to have avoided the _whole_ of those deep cuttings and high embankments of the Liverpool and Manchester Railway, of which the under-quoted extract from Mr. Treasurer Booth’s book gives such glowing descriptions. {30}

Admitting, however, (for the question’s sake) that the “most eminent engineers” and their “assistants of undoubted talents,” by whom these “Pelion-upon-Ossa-like spoil banks, towering over the adjacent land” were ordered—and of which Mr. Booth says, in addition, “this aggregate mass has been removed to various distances, from a few furlongs to between three and four miles; and no inconsiderable portion of it has been hoisted up by machinery from a depth of 30 to 60 feet”—admitting that these gentlemen should have been warranted in expending the hundreds of thousands which were paid for making these mountains between Liverpool and Manchester, by the uncertainty then prevalent as to what velocities were attainable by locomotive engines, it cannot be said that the engineers of the London and Birmingham Railway have any similar justification to plead. That line was not, I believe, laid out till 1831, while the velocities attained on the Liverpool and Manchester Railway, and the short time within which London and Birmingham could, in consequence, be brought of each other, form the main features of the prospectus: rates of from 35 to 40 miles an hour having been (then) _long_ attained on the Liverpool and Manchester railway.

Yet does the “Estimate” laid before Parliament shew no less a sum than 429,286_l._ appropriated to “Excavations, Embankments, and Tunnelling,” which, with “the increase in the number of arches in the Wolverton viaduct,” will give an _estimated_ expenditure of nearly half a million to do that, which, taking _proper_ advantage of the law of motion I am adverting to, would entirely have saved; except where a hill as perpendicular as a wall, or a hollow as precipitous as a well, rendered tunnelling, deep cutting, or filling up, absolutely unavoidable.

At the time the Birmingham Railway was before Parliament last session, maps of it were issued from the office of that company, which gave the “Section of the line of railway; shewing the rises and falls.”

This section is on too small a scale to shew either the height of the embankments or the depth of the cuttings: and though it has not suited my convenience to spare the time necessary for examining the section deposited in Parliament, yet as the cubic yards of cuttings and embankments amount to nearly twenty-three millions: as the map and section I have just mentioned shew ten tunnels (some of which are a mile and upwards in length): and inclined planes, in _unbroken_ rises of 6, 8, 10, 11, 13, 20, and 25 miles, there can be no doubt but that _much_ deep cutting and high embanking is included in it. Now though I do not mean to imply that the expense of _all_ cutting and embanking could have been saved, by taking proper advantage of the power of ascending heights, which is imparted by the momenta of the velocities whereat locomotive engines now go, yet I do mean to state it as my full conviction, that had this railway been (as the second prospectus of the Liverpool and Manchester Railway, stated that line should be) “laid down and arranged with that skill and conformity with the rules of mechanical science, which will equally challenge approbation, whether considered as a national undertaking of great public utility, or as a magnificent specimen of art” the whole of the anticipated expenses of _deep_ cutting and _high_ embanking would have been expunged from the estimates; it being certain, that deep cuttings, high embankments, and _long_ inclined planes are no more evidences of engineering skill, than winning a battle by hard fighting is of generalship: while the expense of the numerous “very small cuttings varying from 8 to 10 feet,” which are spoken of in the “Minutes of Evidence taken before the Lords’ Committees,” might as certainly have been saved, and those rises passed over by the vehicles in consequence of their momentum; as a cricket ball will roll over a mole-hill.

But if these remarks are applicable to the Birmingham Railway—the line of which, was I believe, laid out in 1831—what must be said relative to the _now_ proposed London and Bristol Railway?

For nearly twelve months the principle of avoiding level, and constructing “undulating railways” has been discussed, in consequence of Mr. Badnall having taken out a patent for, and published a work, proposing such “undulating railways”: and though, owing to the fall on your line being wholly (as well as _greatly_) one way, it is not necessary to express any opinion here on a proposition, which appears to have for its object the construction of unlevel railways _in preference_ to level ones, and the labour of toiling up hill for the sake of the momentum to be obtained by running down hill, yet as, in consequence of it, the effect of momentum in carrying moving bodies up ascents, has been largely and widely adverted to for the last twelve months (nearly), it must have been within the expectation of every one, that, let the gentleman who has been employed to lay out the line of the Bristol Railway be anxious as he might, to avoid any “undulating” proposition, he would be equally anxious to call in the aid of all _known_ and _established_ principles, to diminish the expense of the line he was required to lay down. {32}

Now, nothing, I believe, is more certain, than that if a vehicle be moving along a level at the rate of 2¾ (2.7272) miles an hour, it will, on coming to an inclined plane, and provided the operation of the power which overcame friction on the level, be continued, so as to neutralise and (as relates to counteractive effect) annihilate friction during the ascent, “swing” itself up, and rise to the height of (that is, its momentum will cause it to rise to the height of) three inches perpendicular; let the angle of ascent, or rate of rise of the plane, be what it may.

Equally certain is it, that if the velocity of the vehicle be twice 2¾ miles an hour, that is 5.4544 miles, the momentum will (under similar circumstances as to counteraction of friction) then cause the vehicle to rise up said inclined plane to four times the height to which the former velocity raised it; or to the height of one foot. And it is equally certain, that the momenta imparted by increased velocities will, under the circumstance of the friction of the vehicle being overcome, neutralised, and (as relates to counteractive effect) annihilated, by the continued operation of the moving power during the ascent, cause the vehicle to rise up any inclined plane to the perpendicular heights stated in the following table:—

Carriages moving on levels, at the Have momenta, which (friction under-mentioned velocities, the being counteracted and motions of which are changed from neutralised) will cause them horizontal to ascending, by means, to rise to the either of circular or angular under-mentioned heights ascents. (perpendicular) above the level where those velocities were attained: let the rate of rise, or angle of ascent, be what it may. MILES. MILES PER HOUR. PERPENDICULAR. 2¾ or 2.7272 3 inches. 5½ or 5.4544 1.0 foot. 11 or 10.9088 4.0 feet. 22 or 21.8176 16.0 do. 44 or 43.6352 64.0 do. 88 or 87.2704 256.0 do. 176 or 174.5404 1024.0 do. 352 {33} or 349.0808 4096.0 do.

Now, let it have been proper as it may, that the gentleman whose name appears as “Engineer” to the Bristol Railway, should (in laying out that line) have avoided encumbering the subject with the “undulating” question, there can be no doubt that it was incumbent on him to diminish expense in every way which _established_ principles admitted. And as the usual railway rate is now 20 miles an hour, while that rate will give momentum enough to cause any vehicle to rise up any inclined plane to the height of 13⅓ feet (perpendicular) above the level on which it was running at the rate of 20 miles an hour, it is necessary only to lay out the line of this railway in levels, and rises of 10 feet each, to avoid (very nearly, if not _quite_) all necessity for cutting, or embanking; while _deep_ cutting, _high_ embanking, and tunnelling, might (except in _very_ peculiar cases) have been as certainly avoided, as erecting a suspension bridge will obviate the necessity for piers and arches over a river. Yet does not this gentleman appear to have any more called in the aid of this law of motion, than did those equally “_eminent_ engineers” who laid out the line of the Liverpool and Manchester Railway; or those who have laid out that of the Birmingham Railway: the “Report” of the public meeting held at Bristol, on the 30th July last, stating that “although the line of country (except for about 30 miles at the Bristol end) is _very advantageous_, yet the comparative levelness of the railway will be attained by a _great deal_ of deep cutting, and _several_ tunnels;” while the prospectus issued from the London office of the Company states, that “the construction of a road so nearly level, in the hilly country about Bath and Bristol, will, unavoidably, be a costly work.”

The length of the Birmingham Railway is 112½ miles; that of the Bristol Railway “from 115 to 118 or 120 miles,” average 117½. The estimated expense of the cuttings, embankments, and tunnels, of the Birmingham Railway is 429,286_l._ or 3,185_l._ per mile. The same expense on the Bristol Railway is (835,300_l._ + 15,000_l._=) 850,300_l._ or 7,236_l._ per mile; that is, above twice as much: and this too, notwithstanding that the Report states that “this expensive part of the work, fortunately, lies principally in two of the most favourable materials—the chalk and the freestone;” and also notwithstanding that the estimate of the Birmingham Railway has undergone two years’ scrutiny, and the most rigid investigation, by several Parliamentary Committees; while that for the Bristol Railway is the result of only a “_preliminary_ survey,” directed by a “Provisional Committee:” so that were it to be increased as the estimate for the Birmingham Railway has been increased, it would be _many_ times as much as the similar work on that railway. Indeed, the parties themselves have made a considerable increase already: 10 per cent. being added to the above amount of 850,300 by the Bristol Committee, and 7 per cent. by the London Committee; {34a} so that 978,494_l._ is the _whole_ amount at present allowed for works, which taking proper advantage of the momentum of the vehicles would have saved.

Yet, with well-known laws of motion thus set at nought and neglected, and with expense thus unnecessarily as well as most enormously added to, are the Committee—gentlemen who were, unavoidably, as entirely dependant on the opinion of their engineers, as the Ministry of 1789 were upon that of the “Insanity Doctors,” relative to the mental affliction of George III.; or as those of 1830 were on that of the physicians who attended George IV. during his long illness—under circumstances of such entire dependence on the opinion of their engineers, are the “Provisional Committee” of the Bristol Railway led into the following expressions of approbation in their Report: “The Committee think it but justice to say, that the zeal, the diligence, the _ability and other valuable qualities_ manifested by these gentlemen, have given them ample reason to congratulate themselves on their choice”!; and “The Committee, in conclusion, _repeat_ that they have carefully availed themselves of the resources of _skill and experience_ in investigating the probable cost of the railway.” {34b}

Now as, were I to presume to manifest “skill, experience, ability, and other valuable qualities,” _such as these_, with respect to your line, or thus to throw away, not only hundreds of thousands, but also half millions, on any other, I should be sure to experience the truth of that proverb, which says that merely looking over the hedge shall subject one man to the operations of “the _finisher_ of the law,” while another man may steal the horse with impunity, I must avail myself of this law of motion, which “skill, ability, experience, and other valuable qualities” so neglect and despise, to get loads up the rise which you wish to surmount, without resorting to deep cutting or high embanking.

Sixty feet of the rise to be surmounted, occurring in the last half-mile of your line, I shall have nearly two miles to acquire the necessary velocity in: and as the continuation of the action of the power which overcame friction on the level, will neutralise, and, as relates to counteractive effect, annihilate the friction of the carriages while ascending these sixty feet, I have only to cause them to attain a velocity somewhat greater than has yet been attained on railways, that is, 42½ miles an hour during the two miles, to enable them to “swing” themselves up these sixty feet, in consequence of the momentum which that velocity will impart: while, let the height of Rodway Hill (which is adverted to as so desirable to avoid, in the Report of the Provisional Committee of the Bristol Railway) be what it may, all that would be requisite to obviate the necessity for the “inclined plane and stationary engine” spoken of as unavoidable there, would be to attain the velocity due to the altitude of said hill, to enable my vehicles to surmount it from their momentum.

Nor would the ascending power imparted by the vertical operation of the pressure of the atmosphere, be much less important with respect to diminishing the expense of bridging, on the line of this Bristol Railway, than would “momentum” as relates to the expense of cutting and embanking. From the map issued from the London office of that Company, it appears that that railway is to be carried five times across the Avon; twice across the Kennet and Avon Canal; three times across the Wilts and Berks Canal; and four times across the Thames. These various crossings are not for the sake of approaching places of magnitude, or commercial importance; but solely because the _principle_ of railway transmission compels the level to be servilely adhered to: while, though the right line distance between London and Bristol is only 108 miles, yet is the line of railway there laid down, shewn as being 120 miles long; the 12 additional miles being added by the curves taken in thus crossing these waters for the sake of the level.

Now though I do not mean to say that it would be possible, by laying down a tunnel instead of this railway, to avoid all bridging whatsoever, yet owing to hills and rises being no impediment to the operation of this principle, the line for a tunnel might be several miles shorter than this line of the railway, and yet the whole of these bridges be saved, excepting one over the Avon; while not a quarter of the expense would be incurred for carrying a tunnel over the waters which _its_ course must cross, which will be incurred in bridging the railway over those other waters that intersect its course, which are not laid down in the map shewing its line.

The estimated expense of bridging for the railway is 474,800_l._; which, when increased by the per centages allowed by the Committees, amounts to 556,194_l._ as the whole _estimated_ expense of bridging. What proportion of this amount is for bridging over waters, and what for bridging over roads, is not stated. On the Liverpool and Manchester Railway 108,565_l._ 11_s._ 9_d._ was expended on 63 bridges; of which only five were over waters: the other 58 being over roads, or to carry roads over the railway. On the Birmingham Railway the number of bridges is 300; of which only nine _are stated_ to be over waters, the others being for roads. The estimated amount of them is 350,574_l._ One bridge alone (the Sankey viaduct) on the Liverpool and Manchester line, cost nearly 50,000_l._

Now as the power of going up or down, imparted by the vertical operation of the pressure of the atmosphere, would render it wholly immaterial whether the level was preserved in the line of a tunnel; as burying it under ground, in the manner proposed at page 27, would equally do away with any occasion for the _many_ hundreds of bridges, which, on the three lines I have mentioned, must be provided to carry those railways clear of roads, as it would save bridging over the roads on your line; and as a tunnel could have been carried _under_ the Sankey, for almost one-tenth of the expense it cost to construct the viaduct by which the Liverpool and Manchester Railway is carried over that canal—as my principle offers facilities of this kind for obviating the necessity of bridging—I do not hesitate to say, that, on the whole three lines, and considering how much the actual, will exceed the estimated amounts, above one million sterling might be saved in the item of bridging alone, by substituting tunnels for railways; which, when added to, as it would be, by the almost equal amount that would be saved in the expense of the land, in consequence of my plan requiring a width of only ten or a dozen feet _under_ ground, instead of from 60 to 300 on the surface, will admit of my saying that (in round numbers) nearly two millions might be saved by my plan, in these two items of bridging and land, on the lines of the Liverpool and Manchester, the London and Birmingham, and the London and Bristol Railways: while, if what my plan would save of the 398,286_l._ allowed for the cost of land, and of the 261,928_l._ allowed for that of the entrances to London, Bath, and Bristol, be added to the savings I have stated it would effect in bridging, cutting, embanking, and tunnelling, I may say that it would also save nearly two millions (of the _present_ estimated expense) on the Bristol Railway alone.

The ten times greater heights than I have yet specified, which may be surmounted by combining the operation of the momentum of the _air itself_ with that of the vehicles, it is not necessary for me to trouble you with, owing to the shortness of your line, and the small height to be ascended: though it may be permitted me to observe, that as attaining only equal velocities to those which have been spoken of as attainable by locomotive engines and steam-coaches, will enable my vehicles, of themselves, to surmount hills of many hundred feet in height; while combining with their momentum, the momentum of the air itself (that which is _before_ the vehicles; the friction whereof will be overcome, and neutralised by the operation of the exhausting apparatus) in tunnels of proper length, and loads of corresponding weight, will enable me to ascend more thousands of feet, than the momentum of the vehicles alone will carry them up hundreds, I may be able to extend Louis le Grand’s exclamation, “Il n’y a plus des Pyrennées,” to “il n’y a plus des montagnes sur la terre,” so far as relates to their longer preventing intercourse between countries; and consequently render the whole earth level to us, in point of effect.

In reference to the force required to overcome the friction of the medium by which the moving power operated to impel the carriages, would a tunnel be also superior to a railway. From Messrs. R. Stephenson and Locke’s reply to Mr. Walker’s Report to the Directors of the Liverpool and Manchester Railway, it appears that the friction of the ropes by which stationary engines draw waggons up inclined planes, is one-twelfth of their weight: while, as the latter part of your line gives a sharper rise than that of the Liverpool tunnel, the weight of the rope you must use should not be less than 7lbs. per yard; the friction and gravitation of which would be 0.73231b. per yard, or 1289lbs. per mile. The line in the plan for the railway, which was laid before your meeting, being 2½ miles long, the whole resistance of friction and gravitation upon it would be 3222 lbs.

From experiments on the friction of air in tubes, I am enabled to state that both the inertia and friction of the air against the inside of an equal length of the tunnel I propose to you to lay down would not, when said air was moved _by exhaustion_, and conveying 50 tons at the same rate at which the same quantity is drawn up the tunnel of the Liverpool and Manchester Railway (i.e. ten miles an hour), be so much as one sixteenth part of this; while it would have this important advantage, that the heavier the load was, the less would be both the inertia and friction of the air. For instance: the degree of exhaustion requisite to admit of an equal load to what is drawn up the Liverpool tunnel (i.e. 50 tons) being moved up a tunnel of the same size as that I constructed at Brighton, and rising at the same rate your’s must rise (1 in 47) by the pressure of the atmosphere, would be about the 40th part of a vacuum.