Chap. 6.]

A fine specimen of Hydraulic Machinery.

301

sent year (1840) to visit Fair Mount. Six breast wheels (15 feet long and 16 feet in diameter) were in operation; each, by a crank on one end of its axle, communicating motion to the piston rod of a single pump. The pumps are double acting, the same as figured and described at page 271. They are placed a little below the axles of the wheels and in nearly a horizontal position. The cylinders are 16 inches diameter; and, that the water may not be pinched in its passage into and escape from them, the induction and eduction pipes are of the same bore; and all angles or abrupt changes in their direction and those of the mains are avoided. The stroke of two or three of the pumps was four feet, and their wheels made fourteen revolutions per minute: the others had a stroke of five feet ten inches, and the wheels performed eleven revolutions in a minute, consequently the contents of the cylinders of the latter were emptied into the reservoirs twenty-two times in the same period, and those of the former twenty-eight times. The cylinders are fed under a head of water from the forebays and they force it to an elevation of 96 feet, through a distance of 290. An air chamber is adapted to each.

It is impossible to examine these works without paying homage to the science and skill displayed in their design and execution; in these respects no hydraulic works in the Union can compete, nor do we believe they are excelled by any in the world. Not the smallest leak in any of the joints was discovered; and, with the exception of the water rushing on the wheels, the whole operation of forcing up daily millions of gallons into the reservoirs on the mount, and thus furnishing in abundance one of the first necessaries of life to an immense population-was performed with less noise than is ordinarily made in working a smith's bellows! The picturesque location, the neatness that reigns in the buildings, the walks around the reservoirs and the grounds at large, with the beauty of the surrounding scenery, render the name of this place singularly appropriate.

Dr. T. P. Jones, the talented editor of the Journal of the Franklin Institute, promised his readers " A history of the origin, progress and present state of the Water-works at Fair Mount," some years ago, but which has not yet been published. His familiarity with the subject in general, and with those works in particular, would make the history highly interesting to the present generation, and a source of valuable information to future ones. See Journal of the Franklin Institute, vol. iii, first series; which contains a plan and section of one of the wheels and one of the pumps.

What a contrast with the old works at London bridge, where one wheel worked sixteen small pumps; the friction of the numerous pistons and the apparatus for moving them consuming a great portion of the power employed.

302

Fire Engines.

[Book III.

CHAPTER VII.

FIRE-ENGINES: Probably used in Babylon and Tyre-Employed by ancient warriors-Other devices of theirs-Fire-engines referred to by Apollodorus-These probably equal in effect to ours: Spiritalia of Heron: Fire-engine described in it-Pumps used to promote conflagrations-Greek fire, a liquid projected by pumps-Fires and wars commonly united-Generals, the greatest incendiaries-Saying of Crates respecting them-Fire pumps the forerunners of guns-Use of engines in Rome-Mentioned in a letter of Pliny to Trajan, and by Seneca, Hesychius and Isidore. Roman firemen-Frequency of fires noticed by Juvenal-Detestable practice of Crassus-Portable engines in Roman houses-Modern engines derived from the Spiritalia-Forgotten in the middle ages-Superstitions with regard to fires-Fires attributed to demons-Consecrated bells employed as substitutes for water and fire-engines-Extracts from the Paris Ritual, Wynken de Worde, Barnaby Googe and Peter Martyr respecting them-Emble matic device of an old duke of Milan-Firemen's apparatus from Agricola-Syringes used in London to quench fires in the 17th century-Still employed in Constantinople—Anecdote of the Capudan PachaSyringe engine from Besson-German engines of the 16th century-Pump engine from Decaus-Pump engines in London-Extracts from the minutes of the London Common Council respecting engines and squirts in 1667-Experiment of Maurice mentioned by Stow the historian-Extract from 'a history of the first inventers.'

Or the machines described in the 1st and 2d books some are employed in raising water for the irrigation of land, and for numerous purposes of rural and domestic economy; others in various operations of engineering and the arts, but with the exception of the centrifugal pumps, (Nos. 95, 6, and 7,) the liquid falls inertly from them all. e. it is not forcibly ejected as from a forcing pump or syringe: whether it be poured from a bucket, drawn from a gutter, escape from a noria, or from the orifice of a screw, or the spout of an atmospheric pump, it flows from each by the influence of gravity and consequently descends as it flows-such machines are therefore inapplicable for projecting water on fires, because for this purpose the liquid is required to ascend after leaving the apertures of discharge and with a velocity sufficient to carry it high into the air; and also when conveyed to a distance through flexible or other tubes, to be delivered from them at elevations far above the machine itself. As these effects are produced by the pumps described in the present division of the subject, most of them have at different times been adopted as fire-engines; some account of these important machines may therefore be inserted here.

Water is the grand agent that nature has provided for the extinguishment of flames, and contrivances for applying it with effect have, in every civilized country, been assiduously sought for. In the absence of more suitable implements, buckets and other portable vessels of capacity, at hand, have always been seized to convey and throw water on fires; and when used with celerity and presence of mind at the commencement of one have often been sufficient; but when a conflagration extends beyond their reach, the fate of the burning pile too often resembles that of the ships of Eneas: Nor buckets poured, nor strength of human hand Can the victorious element withstand. Eneid, v.

The necessity of some device by which a stream of water might be forced from a distance on flames must have been early perceived, and if we were to judge from the frequency and extent of ancient conflagrations, the prodigious amount of property destroyed, and of human misery induced by them, we should conclude that ingenious men of former times were stimulated in an unusual degree to invent machines for the purpose. That this was the case cannot well be questioned, although no account of their la

Chap. 7.]

Fire-engines employed in Ancient Wars.

303

bors has reached our times. It seems exceedingly probable that some kind of fire-engines were used in the celebrated cities of remote antiquity -in Nineveh, Tyre, Babylon and others. It is scarcely possible that the Tyrian and Babylonian mechanicians, whose inventive talents and skill were proverbial, should have left their splendid cities destitute of such means for preserving them from the ravages of fire. If the great extent of Babylon, for example, be considered, its location, (on an extensive plain,) the length of its streets, (fifteen miles,) the height of its buildings, (three and four stories,) and its unrivaled wealth, together with the heat and dryness of the climate; the necessity of such machines will be apparent, and what appears necessary to us, we may rest assured, appeared equally so to its mechanicians, and that they were quite as capable of providing by their ingenuity for the emergency. Nor are we left wholly to conjecture respecting their knowledge of hydraulic or pneumatic machinery, since the most memorable machine for raising water in the ancient world was made and used at Babylon, and one which, as has been elsewhere observed, greatly exceeded in the elevation to which it raised it, all, or nearly all the water-works of modern days. Had they engines like ours then? We dare not say they had, although we see nothing improbable in the opinion: the antiquity of the syringe is unquestionable; and its application to project water on flames must have been as obvious in remote as in present times; and people would as naturally be led then as now, to construct large ones for that purpose.

There are other reasons for believing that syringes or pumps for squirting water on fires were in use previous to the time they are first mentioned in history. Fire was one of the most common and most destructive agents employed in ancient wars. When a city was besieged or assaulted, it was the first object with the assailants to protect the moving towers, in which their battering engines, &c. approached the walls, from being consumed by fire, oil and pitch, &c. thrown upon them from the ramparts. Every source was examined that ingenuity could unfold, for materials and devices to protect them; and as not only the lives and property of the inhabitants, but often the destinies of armies and even of nations were on such occasions at stake, it is reasonable to conclude that the most perfect apparatus which could then be procured, were employed both for destroying buildings by fire, and also for preserving them from it. We know that men were specially trained to fire buildings, and that they were expert in their profession, especially in shooting lighted arrows and darts into and upon structures that could not be approached; hence the necessity of devices for throwing water upon these missiles and the places inflamed by them. There is an allusion to both practices in the Epistle to the Ephesians, vi, 16. Such a system of warfare could never have been carried to the extent that it was, and for so many ages too, among the celebrated nations of old, without forcing pumps or something like them being used to squirt water on such parts as could not be reached by it when thrown from the hand. We cannot conceive how the constant repetition of one army applying its energies to the destruction of another by means of fire, and the latter equally intent on devising and applying means to extinguish it, without the application of the syringe and of machines on the principle of the bellows occurring to them-an application so obvious (even then) that the slightest mental effort to produce a contrivance for the purpose could not have overlooked it, even if the occasions were of little moment, much less, when the inventive powers of armies, and of military engineers in particular, were engaged in the research, and the fate of nations depended upon the result. From a remark in one of Pliny's

304

Fire Engines mentioned by Apollodorus.

[Book III. letters, to which we shall presently refer, it appears that among the Romans individuals were brought up to the profession of extinguishing fires.

The Helepoles, or 'town takers' of Demetrius, although proofs of his mechanical genius, would have availed him little at the siege of Rhodes, nor the movable towers of Hannibal at Saguntum, if these warriors had not been in possession of means to prevent them from being consumed by the fire of the besieged-of materials to resist its effects, and apparatus to extinguish it. That the resources of the ancients in these respects were not inferior to ours, may be inferred from several historical facts respecting their modes of securing these towers. They were generally covered with raw hides, leather soaked in water, or cloth made of hair, and sometimes, although seldom, they were plated with metal. Such were some of those employed by Titus at the siege of Jerusalem. They were seventy-five feet high and were covered all over with sheets of iron; perhaps nothing else could have resisted the incessant torrents of fire which the infuriated Jews showered upon them. But a singular proof of the sagacity and researches of the ancients is, that the modern application of alum to render wood incombustible was also known; for Archelaus, one of the generals of Mithridates in a war with the Romans, washed over a wooden tower with a solution of it and thereby defeated all the attempts of Sylla to set the structure on fire. Thus we see that when mechanical means failed them, or were not at hand, they had recourse to chemical ones. But that water and machines for dispersing it, were extensively employed on such occasions appears from a remark of Vitruvius. He observes that the lower stories of the towers contained large quantities of water for the purpose of extinguishing fire thrown upon them. Of course they had means of projecting it wherever required, but of these unfortunately he is silent. Montfaucon has engraved a figure of a species of wheel for the purpose, but its representation is too imperfect to indicate the nature of the machine of which it seems to have formed a part.

man.

That machines of the pump kind were used on these occasions is evident from the temporary contrivance of Apollodorus, mentioned in the remains of a work of his On War Machines, and quoted by Professor BeckWe have noticed, at page 235, one of his plans for extinguishing fire in the upper parts of a building, and that to which we now refer is from the same passage. Water, he observes, may be conveyed to elevated places when exposed to fiery darts, by means of the entrails of an ox: these natural tubes being connected to a bag filled with water; by compressing the bag the liquid will be forced through them to its place of destination. This device, he says, may be adopted when the machine called SIPHO is not at hand. Now if we had not known that the term sipho was anciently used to designate syringes and other tubular instruments, the substitute which Apollodorus here proposes sufficiently proves that it was a forcing pump to which he refers, and one too that, like our fire-engines, was furnished with leathern hose through which the water was conveyed to the "elevated places" he mentions. The importance of flexible pipes accompanying the pump or sipho, when employed in war, is obvious; for one of the objects of those who threw "fiery darts" on the towers and other structures, was to fire them, if possible, at places inaccessible to water for the most difficult to be reached-hence the necessity not only of engines, to project streams of that liquid, but also of such tubes to direct it to the places inflamed: and hence the suggestion of the tubes mentioned by Apollodorus when artificial ones were not to be procured : an ox was always within the reach of an army.

As these engines would of course be similar to such as were used to

Chap. 7.]

Fire-Engine described by Heron.

305

extinguish fires in cities in times of peace, it is to be regretted that neither Apollodorus nor Vitruvius has described them: perhaps they were too common to have been thought worthy of particular notice. In the design and execution of their essential parts, they were probably equal to our best engines. Some persons may doubt this, but it should be remembered that the nature of ancient wars naturally led to the best construction of all military machinery; and of defensive apparatus, engines to extinguish fire could not have been the least important, when that element was universally employed. The contests of the ancients were often those of mechanical skill rather than of fighting-conflicts of talent in engineering than in generalship; hence the ingenuity displayed in their machinery and the wonders wrought by it. Archimedes, by superior machines, protected Syracuse for eight months against all the efforts of the legions of Marcellus and the Roman engineers. The successes of Demetrius and Hannibal were often due to the novelty of their engines: the Carthagenian machinists were indeed proverbially skilful, so much so, that in Rome itself any curious piece of mechanism was, by way of eminence, named punic. Ancient armies were also often employed in obtaining, raising and cutting off water; the hydraulic engines of Ganymede nearly ruined Cæsar and his army in Alexandria, Cyrus took Babylon by diverting the course of the Euphrates, &c. The frequent use of hydraulic engines in war either to extinguish fires or for other purposes, would naturally lead to skill in making as well as in using them.

No. 141. Egyptian Fire-Engine of the 2d century before Christ, from Heron's Spiritalia.

That the idea of employing forcing pumps as fire-engines was not new in the time of Apollodorus or Vitruvius, we have conclusive evidence. Among the small number of ancient writings that escaped destruction in those dark and turbulent ages that intervened between the decline of the Roman power and the introduction of printing into Europe, was a Greek manuscript, containing an account of various devices for the application of water, and among them an engine for extinguishing fires. This small work was illustrated with figures, like the original work of Vitruvius. Several Latin translations were made and published in the 16th and 17th