Chapter III: Part 3

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.

But supposing ten times this load were to be raised, the degree of exhaustion must be ten times as great, or about the fourth of a vacuum. And, as the greater the exhaustion, the less the expansive power, and, consequently the less the inertia and friction of the air inside the exhausted part of the tunnel, this “rope of air” as it has, derisively, been called, possesses the important advantage of decreasing as relates to the density, inertia, and friction, which _itself_ opposes, in proportion to the increase of the load drawn by it: while, as the valves I should place at every quarter, or half, or whole mile, to be opened by the carriages as they pass them, and admit air immediately behind said carriages, would prevent there being the inertia and friction of more than a few hundred yards of air of the _natural_ density behind the carriages to be overcome, the impediment which presents an insuperable obstacle in the opinion of the numbers who have condemned the proposition (because they deemed operating by exhaustion the same as operating per plenum) diminishes, in point of fact, to a far less important hindrance, than that which is occasioned by the old system of drawing loads by means of stationary engines and ropes; since, in the present instance, the inertia and friction would not be the one-hundred-and-sixtieth part of what it would be, to move an equal quantity by the stationary engine, and rope system.

And notwithstanding that the superiority which the tunnel possesses over the locomotive system is not so great at this, yet is it important.

In the instructions given to Mr. Walker by the Directors of the Liverpool and Manchester Railway (and which called from him the Report criticised by Messrs. R. Stephenson and Locke), it is stated that “the quantity of traffic for which it will be expedient to provide the power of conveyance” is about 4000 tons, from each to the other of those places, daily.

In his publication on the Liverpool and Manchester Railway, Dr. Lardner says, “In the experiments which I have detailed, it appears that a steam engine is capable of drawing 90 tons at the rate of about 20 miles an hour; and that it could transport that weight twice between Liverpool and Manchester in about three hours.” {38a} The weight of this engine alone being 8.1 tons, the whole weight of itself, and its tender, with the necessary supplies of fuel and water, will not be less than twelve tons. Therefore, the friction of the engines (and their tenders) requisite to carry these 4000 tons at the rate of 20 miles an hour, would be 4267 lbs.

The friction of one mile of air in a tunnel eight feet in diameter, when moved at the rate of 20 miles an hour by _exhaustion_ being 288lbs., the friction of it in a tunnel extending from Liverpool to Manchester, will be 8640lbs.: which, though double the friction of these locomotive engines, might be far cheaper for the following reason; and independent of the circumstance, that I could lay down a tunnel capable of carrying all these 4000 tons at one and the same time, from Liverpool to Manchester, for one-fourth of what that railway has cost; {38b} and also independent of the circumstance that the enormous expense now incurred for the repairs of the locomotives (as stated on page 11) would also be saved.

It is well known that the smaller a steam-engine is, the larger is the proportionate quantity of fuel it requires, and the greater the proportionate expense of working it; while it is equally well known that, owing to the imperative importance of lightness and efficiency over economy in locomotive engines, this disadvantage increases in a most rapid ratio with respect to them. In consequence of this, a quantity of fuel, which, in large stationary engines, such as I should use for exhausting air from the tunnel, would do a given quantity of work, would, in the best of the locomotives on the Liverpool and Manchester Railway, do only one-sixteenth as much work.

Therefore it results, that, notwithstanding the friction of the air in a tunnel 30 miles long would, at the rate of 20 miles an hour, be twice as much as the friction of the locomotive engines, yet, owing to the fuel consumed by the latter, to move themselves and their tenders, being sixteen times as great as large stationary engines, such as I should use, would require to do the same work, the tunnel would, supposing the whole quantity of goods were to be carried at once, be eight times the cheapest mean of conveyance, in point of current expenses only, and without reference to its first cost being only one-fourth that of the railway; and also without reference to the whole of the enormous expense now occasioned by the repairs of the locomotive engines being saved.

But this is not the only proportion in which a tunnel might be cheaper. The 13th paragraph of the Russian Engineer Officer’s Report, states, that he is “convinced that exhaustion to a degree which should give a pressure of fifteen inches of mercury may be effected in the tunnel.” Now, notwithstanding that much more than this may be done in an iron tunnel, yet will I calculate on this only. Fifteen inches of mercury being 7.3 lbs. that pressure on the area of the tunnel, would move above twice the 4000 tons which the Directors of the Liverpool and Manchester Railway estimated would be carried from one to the other of those places every day; which, supposing that weight to be conveyed at one time, would reduce the expense (per ton of goods carried) of overcoming the friction of air moving in a tunnel from Liverpool to Manchester, at the rate of 20 miles an hour, to one-sixteenth of what the power required to overcome the friction of the locomotive engines required to draw the same weight would cost.

And though, owing to its being a received opinion that the power required to overcome the friction of fluids increases according to the square of the velocity, we are to suppose that at 40 miles an hour, the fuel required to overcome the friction of the air would be one-fourth that of the locomotive engines, while at 80 miles an hour it would be equal to that of the engines, still would a quadruple velocity be attained, by the expenditure of only an equal quantity of fuel.

The amount of the power required to overcome the friction of the locomotive engines (and their tenders) necessary to carry 4000 tons weight from Liverpool to Manchester daily, at the rate of 20 miles an hour, is, when expressed in “horse’ power” equal to the power of 225 horses working for an hour and a half. In other words, these locomotives must exert power to this amount, beyond what is required to draw the 4000 tons weight.

The power required to overcome the friction of air, which was moving (by exhaustion) at the rate of 20 miles an hour, in a tunnel of eight feet diameter, extending from Liverpool to Manchester, would be equal to that of 456 horses: which, though double the preceding, would yet be eight times cheaper, owing to large stationary engines, such as I should use, requiring only one-sixteenth part of the fuel required by locomotives to do equal work.

At 40 miles an hour (supposing locomotives could go so fast) the number of horses’ power required to overcome the friction of the air in the tunnel would (according to the received opinion of that friction increasing to the square of the velocity) be 3650: which, though sixteen times greater than that of the locomotive engines and their tenders, yet, in consequence of this power being exerted only for three-quarters of an hour, instead of an hour and a half, and of fuel doing sixteen times as much work in large stationary engines as in locomotives, would be only half so expensive as the locomotives and their tenders would prove.

At 80 miles an hour (which is twice as fast as locomotives can go) the power required to overcome the friction of the air in the tunnel, would (on the calculation that it increases according to the square of the velocity) be equal to that of 29,196 horses; which is nearly 130 times as much as the locomotive engines would require: though, owing to this power operating only 22½ minutes, instead of an hour and a half, and to fuel in large stationary engines doing sixteen times as much work as in locomotives, the expense would be only twice as great as in the locomotives, exclusive of the whole of the most enormous expense now incurred, by the repairs of the locomotives being saved (which would, alone, more than make up the difference) and also exclusive of the tunnel costing only one quarter of what the railway has cost, and of the rate of conveyance being four times as fast.

But it is not with respect to a tunnel only, that the resistance of the air opposes an impediment: this resistance being found so serious an obstacle to the progress of the locomotive engines and their loads, that in all trials of, or experiments with them, the state and direction of the wind is noted and allowed for. In the “Account of the Liverpool and Manchester Railway,” published by the Treasurer of that Company (H. Booth, Esq.), he says: “Moreover, at great velocities, the resistance of the air must not be left out of the calculation. At ten miles per hour, it has been found by experiment, that the resistance of the atmosphere is about half a pound weight on a square foot of flat surface; at fifteen miles, the resistance is 1lb. per square foot; and at twenty miles, about 2lbs. per square foot: the increased resistance being, nearly, as the squares of the velocities.” {40}

The surface opposed to the air by a steam-coach, the engines of which its proprietor told me were equal to ten horses power, I found to be 30 square feet. That, opposed by another, the engines of which were said to be equal to twenty horses power, I found to be above 50 square feet: while, when carrying four outsides on the front of the roof, this coach exposed nearly 70 square feet to the action of the air. The surface opposed to the air by the large locomotive engines now used on the Liverpool and Manchester Railway, I understand (when chimney, axle-tree, wheels, and every thing that cuts the air, is taken into account) to be about 40 feet square. Supposing it to be so, at 20 miles an hour, the air will oppose resistance equal to 80lbs. to the progress of the engine; which resistance having to be overcome at the rate of 1760 feet per minute, is equal to 4¼ horses power. At 40 miles an hour, this resistance would be 320lbs.; which resistance having to be overcome at the rate of 3526 feet per minute, would be equal to 34 horses power. At 80 miles an hour, the resistance of the air would be 1280lbs.; which resistance, having to be overcome at the rate of 7,040 feet per minute, would be equal to 270 horses power; while at 100, and 120 miles an hour, the power required would be, respectively, that of 528 and 912 horses.

Now, as the force required at 80 miles an hour, is a _few_ times more than the whole power of those engines, and as Dr. Hutton found that giving the moving body the form of a cone, the height of which equalled the diameter of its base, diminished the resistance of the air only half, it may serve to shew that the statements of those who have given currency to the opinion that we may be conveyed at _any_ velocity on railways, are promulgated by persons who pronounce upon questions without examining them: since, in addition to this resistance of the _air_ to the locomotive engines themselves, would be its resistance to the tenders, and coaches or waggons they drew; and that, too, independent of, and additional to, the resistance opposed by the _railway_ friction of the engines, tenders, and loads, behind them.

That something of this kind prevents _very_ high velocities from being attained on railways, is evident. At the locomotive engine competition on the Liverpool and Manchester Railway four years ago, velocities of from 35 to 40 miles an hour, were attained by engines which were not one-tenth the power of some of those now used; while, at the opening of that railway, three years ago, the engine by which the surgeon was brought to Mr. Huskisson, after his deplorable accident, went 15 miles in 25 minutes, which is at the rate of 36 miles an hour. Yet do not the so much more powerful locomotives now used on that road, go faster than this: a circumstance which may prove that the limit to the velocity of railway conveyance, will arise from a source not calculated on.

“But,” it may be observed, “this objection to the possibility of very high velocities on railways, is counterbalanced by the dilemma in which you place yourself, by supposing it to be possible that any such power as that of 29,196 horses, can, at one time, be made to operate on a tunnel; since, as relates to practical application, it would prove ‘an impossible quantity.’”

The inference I deny; and, when necessary, will disprove. {41} But the term I accept; and will avail myself of, to shew that it is equally “an impossible quantity” that even if a tunnel were ten times as long as one between Manchester and Liverpool, the friction of air which is caused to move in it, in consequence of exhaustion taking place at the opposite end, can ever oppose an impediment such as is here adverted to.

According to the opinion that the friction of the air would increase as the square of the velocity, the friction of the column of air, which, when moved by exhaustion at the rate of 20 miles an hour, in a tunnel eight feet diameter and a mile long, was 288lbs., would, when moved at the rate of 80 miles an hour, be 4608lbs.; which, on the whole area of the tunnel, would be equal to 1.3 inches of mercury. Therefore, supposing that at every mile of a tunnel extending from Liverpool to Manchester, barometer tubes were to be inserted, the bottoms (or basin ends) of which should be open to the atmosphere, and the tops open to the inside of the tunnel, the mercury in each successive tube would (reckoning _towards_ the end at which the exhaustion took place) rise 1.3 inches higher than that in the preceding.

Now as 1.3×23 gives 30, while 1.3×30 gives 39, it appears that at 23 miles from that end of the tunnel at which the atmosphere was admitted, and seven from that where the exhaustion took place, there would be such a vacuum as would raise mercury the _whole_ height of the barometric column; while, at the end of the 30 miles there would be—or rather _ought_ to be, according to this calculation—39 inches of mercury; or a vacuum and a third; which, in addition to its being “an impossible quantity,” places those who contend that the resistance of the friction of air which is caused to move through a tunnel by the pressure of the atmosphere in consequence of exhaustion taking place at the opposite end, increases according to the square of the velocity, in the dilemma of assuming that there is a certain place in a tunnel 30 miles long, where, notwithstanding that a man, a horse, or even an elephant, might walk as freely and unobstructedly along, as a mouse could through a rat-hole, that subtle, permeating, and all-pervading element which we breathe, would, like the stream of the Jordan when under the influence of the miracle by which the Israelites passed over that river, stop, stick fast, and be unable to move farther; a position, which necessarily throws us for an escape from this dilemma, on the conclusion that, though it is certain that the friction of air against the inside of the tunnel will be an impediment, and though it is probable that this impediment will be of some importance, yet must it be equally certain that it will not be the serious impediment which it is _supposed_ it will prove: and it may therefore, safely be assumed, that the objection which presents an insuperable obstacle in the minds of the many who have condemned the method of operation by exhaustion which I propose (because they deemed it analogous to operating per plenum) becomes removed, and is found to be what all the other “insuperable objections” which have been arrayed against the proposition are found to be when grappled with; i.e. baseless and unreal: it being necessary only to put a valve at every half, or quarter of a mile, which should be opened by the carriages as they passed, to render the length of the column of air of the natural density, which _must_ be behind the carriages to drive them along, only a few hundred yards, and its friction consequently unimportant; said valves being (as can easily be done) so arranged, as to close themselves again the moment the carriage had arrived at, opened, and passed by, the next succeeding one.

But though I freely admit that the friction of the air against the inside of the tunnel may waste power to a degree which shall prove not unimportant, yet may it be doubted whether it will be more important than the waste of power occasioned by the present method of railway transmission by locomotive engines.

In the documents laid before the Lords’ Committees on the London and Birmingham Railway, by the Treasurer of the Liverpool and Manchester Railway, on the 28th June, 1832, it is stated that the “number of trips of thirty miles” performed (or travelled) by the locomotive engines between Liverpool and Manchester, in the half year ending the 31st December, 1831, was “5392”: which, as the same document shews that the _whole_ amount of profitable weight conveyed over those 30 miles during that half year was less than 91,000 tons, gives an average of only 17 tons as the profitable weight carried each “trip.” The weight of the engines by which these loads were drawn it may be difficult to fix upon: though, as the locomotives now used on that railway, are, some of them, above six tons, others above eight, and others above ten tons in weight, it may, perhaps, be fair to take eight tons as the average weight. The weight of the tenders with fuel and water, appears to be rather a delicate subject. The weight of the tender of the Rocket, with its load of fuel and water, at the grand locomotive engine competition in October, 1829, was three-fourths that of the engine itself. There have since been many accounts of immense loads drawn on the railway, of which those by Dr. Lardner, in his “Lectures on the Steam Engine,” are considered as “by authority.” But though we find the weights of the engines, as well as of the loads, and various other particulars (even to the state of the wind) given, yet does it happen that the weights of the tenders, with their supplies of fuel and water, are “unascertained” and omitted, throughout. Under these circumstances, I can do no other than act on the best information I have obtained, and suppose the weight of the engines and tenders with their cargoes of fuel and water to be twelve tons for each “trip.”

Assuming it to be so, the weight of the moving power will be above two-thirds of the profitable weight conveyed; while, supposing the same proportion to obtain as to the 4000 tons just mentioned, the amount of the effect of the friction of the power by which they were conveyed at the rate of 20 miles an hour, would be twice and a half as much as the friction of the air would be in a tunnel when twice the tonnage was conveyed from Liverpool to Manchester in it, at the same rate; which, for equal quantities, is five times the friction while, as relates to the fuel consumed, it would be _very_ many more times than this, dearer.

There is one class, who, above all others, might derive benefit from properly considering what I thus submit, relative to the friction of the air.

When what was termed “the railway mania” was at its height, it was calculated that no body of men would be so much benefited by it as the iron trade; in proof of which the following statement was circulated:—

“We are authorised to state, that the rail-roads already projected,
will require considerably more than two millions of tons of iron.
Now, as iron has recently advanced from 7_l._ to 14_l._ per ton, it
appears that the iron masters (by the way, the originators of, or
principals in, many of these schemes) will receive from the
subscribers twenty-eight millions sterling.”

But, instead of the iron trade having been benefited by the principal portion of what is expended on railways being for their article, scarcely more than one-twentieth-part has been expended for iron; the remainder having gone for labour in “cutting and embanking,” &c. &c.

In the account in Mr. Treasurer Booth’s book, of the expenses of the Liverpool and Manchester Railway, the line which, in the statement, runs “Iron rail account,” gives only 66,830_l._ as paid to the iron masters: the other hundreds, which make up the aggregate of 67,912_l._ there mentioned, being for “oak plugs, freights, und cartages;” which is little more than one-twentieth part of the whole that has been expended on this railway.

The rails of the London and Birmingham Railway are to be half as heavy again as those of the Liverpool and Manchester Railway. Yet does the expense of the “rails, chairs, keys, and pins,” in the estimate of that railway laid before Parliament, amount to only 212,940: one twelfth, that is, of the two millions and a half, which form the aggregate of the estimate there given in.

One of the inducements which railway advocates have held out to the landed proprietors of the Houses of Parliament, in order to lead them to support railway bills, has been the degree to which poor rates, &c. would be diminished, in consequence of the labourers there would be employed in digging out the earth for the cuttings and embankments, in the different parishes through which the lines of railway would run; and in the papers of the end of June and the beginning of July (1832) is a _very_ long advertisement of the London and Birmingham Railway Company, one part of which states that “The _landed interest_ will be benefitted by the expenditure of _upwards_ of two millions of the capital of the Company in labour.”

According to their own shewing, therefore, the expenditure for the benefit of the landed interest will be “_upwards_ of two millions,” while the cost of the iron rails, &c. will be only upwards of two hundred thousand pounds. And as both this, and other advertisements, and the evidence before Parliament, announce the extension of the railway from Birmingham to Liverpool, when this first half of it from London to Birmingham is done—which extension will be about the same length as this first half—the statements of the railway advocates themselves, give the iron masters to see, that the result of the time, trouble, and expense, which they (the iron masters) have devoted to bring forward railways, is, to put more than a shilling into the pockets of the agricultural interest (by the degree to which they will save parish rates, &c. &c.) for every farthing they put into the pockets of the iron masters themselves; all that is saved to country parishes, being actual gain to the agricultural interest; while the 12th or 16th paid to the iron trade is for value in iron; out of which the usual trade profit is all that the iron masters will gain. In other words, about four millions sterling will be paid _for_ the parishes between London and Liverpool, in the shape of wages for labourers, while only about four hundred thousand pounds will be paid _to_ the iron masters for the iron rails, &c.; out of which the iron masters will have to pay the wages of their men who smelt &c. the iron, and the royalties (or rent) for the ore, coal, &c. &c. used in making it.

The difference there is in the specific gravities of ore, coal, and limestone, in different places, will render any estimate _not_ correct for every place; though, generally speaking, I believe it may be received that the quantity of iron stone, coal, and lime stone, which it is necessary to raise to produce a ton of pig iron, will be about 6½ cubic yards.

In the evidence laid before the Lords’ Committees upon the London and Birmingham Railway, it is stated that the whole amount of “earth work” required for that railway, amounts to 22,779,431 cubic yards; of which a detailed statement is given in the minutes of evidence.

Dividing the twenty-three (nearly) millions of cubic yards of “earth work” which are to be excavated and embanked on the Birmingham Railway, by the number of cubic yards of ore, &c. which it is necessary to dig to make a ton of iron, will show, that if the wages which will be paid for levelling on that railway, were to be expended in digging iron ore, &c. the nation would be benefitted by having three millions and a half tons of iron more than it now possesses; while the labour expended on the railway will be not only worth nothing to the nation, but also worse; insomuch as it appears by the evidence before the Lords’ Committees that it will render 1250 acres of land, which are now cultivated and productive, sterile as a turnpike road.

It is supposed by Mr. Treasurer Booth, in his book on the Liverpool and Manchester Railway, that three thousand miles of rail-road, will, eventually, be laid down in England.

Supposing these 3000 miles to require “earth work” (cuttings and embankments, i.e.) in the same proportion that the London and Birmingham Railway will do so, and also supposing that the wages which will be paid to the Irish, &c. labourers, who do the digging for this “earth work,” were, instead, to be paid to the workmen of the iron masters for raising ore, &c. &c. and converting it into iron, the nation would be richer by nearly one hundred million tons of iron, than it will be if these said wages are paid merely for “cutting and embanking” for railways.

Now though I do not mean to insinuate that this hundred million tons of metallic worth, would increase what is now termed the “monetary wealth” of the nation, yet, as surely as their ignorance (and consequent want) of iron, rendered Mexico and Peru such easy conquests to the iron of the Spaniards, as to make them most striking examples of the truth of Solon’s warning to Crœsus, “He who has more iron, will soon be master of all this gold,” so surely would the possession of this hundred million tons of iron, be enormously more advantageous to the nation, than the cuttings and embankments required for these 3000 miles of railway will be.

Although iron be not, at the present day, either with ourselves, or in any other part of the world, the symbol of value, medium of exchange, and _money_, which Lycurgus made it in Sparta, when that state was in her glory, yet has it, as a commodity which will obtain us the gold and silver of Mexico and Peru in exchange for it, a value, which will procure us the amount of its worth in those metals, as certainly as any other commodity that we export. In whatever proportion, therefore, this hundred million tons of iron would procure us either the gold or silver, the corn and flour, the silks and cottons, the wines and wools, the tea and coffee, the sugar and spices, &c. &c. of other countries, would devoting the wages which will be expended in cutting and embanking for these 3000 miles of railway, to the raising and smelting of iron ore, be more valuable to the nation at large, than if so employed.

Nor is this all; since the substitute I propose for railways, would give us food for one hundred thousand people, which these railways will deprive us of.

The documents laid before the Lords’ Committees, state, that this Birmingham railway will cover and throw out of cultivation, 1250 acres of land. Supposing the proportion thrown out by the 3000 miles of railway to be the same, the whole amount will be 33,333 acres. Allowing these acres to produce three quarters of corn each, is no very excessive allowance. {45} And each individual of the kingdom being estimated to consume a quarter of corn every year, here is land that would produce bread for one hundred thousand people thrown out of cultivation by the railway system.

Now as, in addition to its being perfectly _practicable_ for my tunnels to be buried underground, it would be decidedly best for themselves, and for the operation of the principle, that they should be so; and as ploughing, sowing, reaping, mowing, and all other operations of agriculture, may go on over them, as over any drain, or water-pipe, there is, in addition to the _metallic_ difference which my plan would make to the riches of the nation, the circumstance, that, besides providing this exchangeable metallic wealth, or exportable value, it would also provide us, every year, with food for one hundred thousand more people, than the railway system can provide for.

The _metallic_ part of the question being, however, that which concerns the iron trade, I will keep to that.

One of my early views of this method of conveyance, was, that it _might_ prove important to the iron trade, from the much greater quantity of their production which it would consume, than railways require: and it has, for these seven years, been an object with me, to awaken the attention of the iron masters to (as I conceived) its importance to them, and to endeavour to convince them of the propriety of giving to a plan, which would consume _tons_ of their article, where railways consume only hundred weights, the same fostering and support which they gave to bringing forward railways.

But it has not pleased the iron masters to see the case in the same light in which it presented itself to me.

It is well known to them, that in the year 1810 we had neither a steam-vessel nor a gas-work in the kingdom: the propositions to adopt both those important inventions being _then_ termed and treated, just as this proposition of mine is now termed and treated, i.e. as “impossible, absurd, and madness to think of.” Yet have they seen that a sum of (roundly speaking) ten millions, has, since that period, been sunk in the construction of gas-works and steam-vessels.

With proofs such as these before them (and which have led to the consumption of so much of their production as gas-works and mains require), that, what they, a few years ago, deemed utterly impossible, may, nevertheless, be quite the reverse—it might have been supposed that the iron masters would not prove, either incredulous to, or bigoted against, the belief that a still more important extension of the use of their article was about to open to them.

But, to my great surprise, I have found, that of all unbelievers, the iron masters have proved the most unbelieving.

Other people doubted only because the want of knowledge on the subject, which they openly avowed, left them no alternative. But, in the iron masters, I have had “to contend with the pride of false knowledge.” The world at large said, “We cannot believe, because we cannot understand.” But the iron masters say, “We do not believe, because _we_ know better.”

On asking them how and why they “knew better,” I found that it was not, as some might suppose, from any doubt or difficulty as to the tunnel itself; which they admitted could be cast and laid down, of any size or dimensions that might be required. Neither was it from any doubt as to steam-engines or air-pumps being large and powerful enough to do what was necessary;—the tens of thousands of gallons of air ejected per minute, from the air-pumps which they use to blow the fires of their smelting-furnaces, and the hundreds of horses power they know steam-engines are made equal to, removing all question on these points. {46} But their incredulity arose from a difficulty which one of them had met with, in forcing air through a pipe; and of which they supposed me ignorant; but to which I had adverted, in a publication years before, in the following words:

“It is too well known, to be at all affected in point of veracity, by
an inability to mention either the exact time or place, that the
proprietor of an iron work in Wales had, some years ago, occasion to
erect an additional furnace, at the distance (recollection states) of
about three-quarters of a mile from his old ones. The blast
apparatus of these old works being large enough to supply this new
furnace in addition to the old ones, he conceived it would prove much
cheaper, if, instead of having power and blast cylinders erected at
the new work, he were to lay a pipe from the old ones, to convey to
the new one the superfluous blast. This he accordingly did; and as
soon as the pipe was completed, set the apparatus going, to ascertain
the strength of the blast he could thus apply to the new furnace. To
his great surprise, however, no blast was produced; a gentle current,
which would hardly blow a candle out, being all that was perceptible.
For a result so adverse to his expectation, he could account in no
way but by supposing that, from accident or design, the pipe was
stopped up. As the readiest way to ascertain whether it was so, he
put a cat in at one end, and blocked it up, leaving her to find her
way to the other.

“Thus situated, puss had no alternative but that of seeking an exit
at the other end: this she accordingly did, and, contrary to his
expectations, soon made her appearance there. Convinced by this that
the pipe was not stopped up, he concluded that the disappointment he
had experienced arose from the friction of the air against it; and
finding that he could in no way obviate this difficulty, he was
obliged to abandon the design, and be at the additional expense of
blast apparatus for his new furnace.

“Now, had the proposition this treatise submits, been, that we should
convey ourselves through a tunnel such as has been adverted to, by
employing apparatus on the principle of blast furnaces, to blow us
through, by _forcing_ air in behind us, the circumstance which has
just been stated would be fatal to that proposition. But when,
instead of being blown through, by air _forced_ in behind us, it is
proposed to cause the air which is behind the vehicle to operate to
push it forward, in consequence of some being taken from before it,
the case is widely different. Air which is forced to move in a pipe,
in consequence of other air being driven into that pipe behind it,
operates (in degree) as a wedge, and opposes to the power which moves
it, resistance, arising from becoming, as it were, wedged against the
pipe, through its whole length. But air which, instead of being
_forced_ to move by an impulse from behind, that, as it were, wedges
it against even the very end of the pipe it enters at, is _allowed_
to move, owing to some being taken out from before it instead of
being forced in behind it, becomes affected as any thing from which a
wedge is _withdrawn_ is affected; that is, freedom of motion is
allowed, and its parts play so much more freely, that friction is
diminished instead of increased. The impediment would prove,
therefore, less important in this case than in the other, even were
there no method of altogether obviating it; happily, however, the
means of doing this are in our power. Between driving a vehicle
through the proposed tunnel by forcing air in behind it, and
according to the method which has been stated, there is this
difference,—that in the former case the impulse can be given only
from the end where the moving power operates; while, in the latter,
arranging valves, which should be opened by the vehicle as it passed
over them, would admit of that impulse being renewed at every hundred
yards, could it be necessary to do it so frequently. Let the
friction of the air against the pipe be what it may, therefore, a
valve at every mile, or at every half or quarter of a mile, which (as
may be done) should be opened by the vehicle as it passed along, and
caused to remain open till it (the vehicle) had arrived at the next
valve, would prevent any diminution of the velocity at which we might
be conveyed, that would prove important.

“This reasoning may be illustrated by a figure relating to an
experiment. Air was forced through a pipe 56 feet long, at the rate
of 20 miles an hour, under a pressure which is equal to 2.2 inches of
water; and as it required a pressure which is equal to 0.6 inches of
water to make air move at that rate through a hole in the side of a
vessel, there was consequently 1.6 inches greater pressure at that
end of the pipe at which the air entered, than at the end from whence
it issued.

“Now if the length of the pipe—the tenths of pressure at the
entering—and those at the issuing end, be expressed by two lines
approximating each other, as shewn below, it may be conceived how
‘air which is forced to move in a pipe in consequence of other air
being driven into that pipe behind it, operates as a wedge; and
opposes to the power which moves it, resistance, arising from
becoming as it were wedged against the pipe, through its whole
length.’”

[Picture: Two lines illustrating the above point]

“Since the length of these two lines bears the same proportion in
hundredths of an inch to 56 feet, as the spaces between the ends of
them bear (in tenths of an inch) to 2.2 inches of water, and 0.6
inches of water; {48a} and if we conceive that forcing air to move in
this way, is, in some degree, analogous to drawing an elastic endless
rope, the size of which should be equal to the larger end of the
pipe, through it, and out at the smaller end, we may form some idea
of the degree to which power would be absorbed in operating by a
plenum. And not only this; since, reversing the operation, and
supposing the rope to be drawn from the smaller to the larger end,
will also give us some idea of the effect of operating by exhaustion,
or vacuum; and enable us to conceive that ‘air which is allowed to
move, owing to some being taken out from before it, instead of being
forced in behind it, becomes affected, as any thing from which a
wedge is withdrawn is affected; that is, freedom of motion is
allowed, and its parts play so much more freely, that friction is
diminished instead of increased.’”

Unconvinced, however, by arguments of this kind, the iron masters persist in maintaining what I propose to be impossible, because one of them found that the _exactly reverse_ process is so. In other words, they act just as those “impossibleists” did, who, in their ignorance that high steam would admit of the vacuum, air-pump, ponderous condensing chest, and ton of cold water per horse power per hour, which are inseparable from low-pressure engines, being dispensed with in high-pressure engines, pronounced it to be utterly impossible ever to make steam-engines capable of running upon roads, because such engines could neither carry the ponderous apparatus inseparable from the condenser, nor the immense quantity of cold water required to produce the vacuum which, alone, renders low-pressure engines efficient.

In vain did I point out to them, not only that I had not overlooked their objection, but that my earliest views of the subject, had adverted to, and expressly guarded against it. It was of no use: for no “Demetrius” or other “craftsman” of that day ever vociferated, “Great is Diana of the Ephesians!” more perseveringly, than the principal iron masters of the present day have exclaimed in honour of the idol “Impossible,” whom it pleased them to set up and worship, in opposition to the (as they deemed it) heresy I presumed to attempt to teach them.

Had they done me the honour to _prove_ me heretical, and that theirs was the _true_ faith, I should have been importantly benefitted, as well as convinced: insomuch as it would have prevented me from devoting at least seven additional years of time, and all the means in my power during that period, to the subject. But when they would not trouble themselves to _examine_, and condemned, solely because they proclaimed “impossible,” a method of operation, which I not only did _not_ advocate, but which my publications proved I had long and openly disclaimed, I could not but feel, first, the truth of Dr. Robertson’s observation, “As in Genoa ignorance had opposed and disappointed Columbus, in Lisbon he had to combat with prejudice, an enemy no less formidable;” and, secondly, that just as the reasoning of the pilot who was chosen to execute the treachery planned against Columbus, failed, because he had courage only to go half-way, so did the reasoning of these gentlemen fail, because they have done only _half_ what is necessary to disprove the practicability of what I propose. {48b}

In publications, besides that just quoted, I have not only stated my conviction that the method of operation which the iron masters condemn would be impracticable, but also have endeavoured to analyse the question, and show _why_ it would be so. But as I do not, like them, stop there, and (in effect) say that it must ever be impossible to discover a “North-West Passage,” or reach the _North_ Pole, because Captain Cook could not get within 30° of the South Pole, these gentlemen are pleased to act the part of “Alexander the coppersmith,” against me, rather than to give themselves the trouble of examining whether the part of another Alexander might not prove more honourable, as well as more advantageous to them.

The quotation given a few pages back, states that the price of iron was raised from 7_l._ to 14_l._ in 1825, in consequence of what was then called “the railway mania.” But, so far from maintaining this price, the following extract from a Memorial, which was agreed to at a meeting of the Staffordshire Iron Trade, held at Dudley, on the 4th October, 1831, shews, that in six years the price of iron had fallen lower than ever before was known.

“Memorial to the Right Honourable Earl Grey, First Lord of His
Majesty’s Treasury.

“We, the undersigned Iron Masters, of the Staffordshire Iron and Coal
district, think it our duty respectfully to represent to His
Majesty’s Government the following facts: