Imagens das páginas
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Chap. 16.]

for Hiero, two centuries B. C.

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of different colors, (mosaics) representing scenes from Homer's Iliad. The doors, windows and ceilings were finished with wonderful art,' and embellished with every kind of ornament. The kitchen is mentioned as on this deck and next to the stern, also three large rooms for eating. In the third gallery were lodgings for the soldiers, and a gymnasium or place of exercise. There were also gardens in this vessel, in which various plants were arranged with taste; and among them walks, proportioned to the magnitude of the ship, and shaded by arbors of ivy and vines, whose roots were in large vessels filled with earth. Adjacent to these was a room, named the apartment of Venus,' the floor of which was paved with agate and other precious stones: the walls, roof and windows were of cypress wood, and adorned with vases, statues, paintings, and inlaid with ivory. Another room, the sides and windows of which were of box wood, contained a library; the ceilings represented the heavens, and on the top or outside was a sun dial. Another apartment was fitted up for bathing. The water was heated in three large copper cauldrons, and the bathing vessel was made of a single stone of variegated colors. It contained sixty gallons. There were also ten stables placed on both sides of the vessel, together with straw and corn for the horses, and conveniences for the horsemen and their servants. At certain distances, pieces of timber projected, upon which were piles of wood, ovens, mills, and other contrivances for the services of life.

At the ship's head was a large reservoir of fresh water, formed of plank and pitched. Near it was a conservatory for fish, lined with sheet lead, and containing salt water; although the well or hold was extremely deep, one man, Atheneus says, could pump out all the water that leaked into her, by a screw pump which Archimedes adapted to that purpose. There were probably other hydraulic machines on board, for the plants, bathing apparatus, and kitchen, &c. The upper decks were supplied with water by pipes of earthenware and of lead; the latter, most likely, extending from pumps or other engines that raised the liquid; for there is reason to believe that machines analogous to forcing pumps were at that time known.

The Syracusan' was laden with corn and sent as a present to the King of Egypt, upon which her name was changed to that of the 'Alexandria.' Magnificent as this vessel was, she appears to have been surpassed by one subsequently built by Ptolemy Philopater; a description of which is given by Montfaucon, in the fourth volume of his antiquities.

For the Spiral Pump of Wirtz, see the end of the 3d Book.

CHAPTER XVII.

THE CHAIN PUMP-Not mentioned by Vitruvius-Its supposed origin-Resemblance between it and the common pump-Not used by the Hindoos, Egyptians, Greeks or Romans-Derived from ChinaDescription of the Chinese Pump and the various modes of propelling it-Chain Pump from AgricolaPaternoster Pumps-Chain Pump of Besson-Old French Pump from Belidor-Superiority of the Chinese Pump-Carried by the Spaniards and Dutch to their Asiatic possessions-Best mode of making and using it—Wooden Chains-Chain Pump in British ships of war-Dampier-Modern improvements -Dutch Pump-Cole's Pump and experiments-Notice of Chain Pumps in the American Navy-Description of those in the United States Ship Independence-Chinese Pump introduced into America by Van Braam-Employed in South America-Recently introduced into Egypt-Used as a substitute for Water Wheels-Peculiar feature in Chinese ship building-Its advantages.

The chain pump, although not described by Vitruvius, is introduced at this place, because it seems to be the connecting link between the chain of pots and the machine of Ctesibius. Some writers suppose it to be derived from the former; nor is the supposition improbable. Numerous local circumstances would frequently prevent the chain of pots from being used in a vertical position, and when its direction deviated considerably from the perpendicular, some mode of protecting the loaded vessels while ascending rugged banks, &c. became necessary. An open trough or wooden gutter through which they might glide, was a simple and obvious device, and one that would occur to most people; but such a contrivance could not have been long in use before the idea must have been suggested, that pieces of plank or any solid substance which would occupy the entire width of the gutter, might be substituted for the pots, since they would obviously answer the same purpose by pushing the water before them when drawn up by the chain. If this was the process by which the transition of the chain of pots into the chain pump was effected, there can be little doubt, that old engineers soon perceived the advantages of covering the top of the gutter, and converting it into a tube; as the machine could then be used with equal facility, in a perpendicular, as in any other position.

It may be deemed of little consequence to ascertain the circumstances which led to the invention of the chain pump; yet a knowledge of the period when this took place would be of more than usual interest, on account of the analogy between it and the ordinary pump, and of the relationship that appears to exist between them. The introduction of a tube through which water is raised by pallets or pistons, is so obvious an approach to the latter, that it becomes desirable to ascertain which of them bears the relation of parent to the other, or which of them preceded the other. But to what ancient people are we to look for its authors? Not to the Hindoos, or the Egyptians, for it is incredible that either of these people should have lost it, if it was ever in their possession. Its cheap and simple construction-its efficiency and extensive application, would certainly have induced them to retain it in preference to others of less value. Nor does it appear to have been known to the Greeks; for their navigators would never have employed the screw as a ship pump, (as Atheneus says they did,) if they had been acquainted with this machine. Of all hydraulic tube machines, the screw seems the most unsuitable for such a purpose. It requires to be inclined at an angle that is not only inconvenient but generally unattainable in ships. But if the Greeks had

Chap. 17.]

Chain Pump.

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the chain pump, the Romans would have received it from them; whereas, from the silence of Vitruvius, it is clear that his countrymen were not acquainted with it. As an engineer, he would have been sensible of its value, and would have preferred it in many cases, in raising water from coffer-dams, docks, &c. to the tympanum and noria, which he informs us were employed in such cases. Arch. Book v, Cap. 12. Moreover, if it was employed by the Romans, it would have been preserved in use, as well as other machines for the same purpose, either in Europe or in their African or Asiatic possessions; but we have no proof of its use at all in any of the latter, nor yet in the former, till comparatively modern times.

But if the origin and improvement of the chain pump is due to one nation more than another, to whom are we indebted for it? To a people as distinguished for their ingenuity and the originality of their inventions, as for their antiquity and the peculiarity of many of their customs; and who by their system of excluding all foreigners from entering the country have long concealed from the rest of the world many primitive contrivances, viz. the CHINESE. This singular people appear to have had little or no communication with the celebrated nations of antiquity, a circumstance to which their ignorance of the chain pump may be attributed. This machine has been used in China from time immemorial, and as connected with their agriculture, has undergone no change whatever. The great requisites in their husbandry are manure and water, and to obtain these, all their energies are devoted." Of such importance is this instrument to irrigate the soil, that every laborer is in possession of one; its use being as familiar as that of a hoe to every Chinese husbandman," "an implement to him not less useful than a spade to an European peasant." It is worthy of remark too, that they often use it, in what may be supposed to have been its original form, viz. as an open gutter; a circumstance which serves to strengthen the opinion of its origin and great antiquity among them. Like the peculiarity of their compass, which with them points to the south, it is a proof of their not having received it from other people. "The Chinese [observes Staunton] appear indeed to have strong claims to the credit of having been indebted only to themselves for the invention of the tools, necessary in the primary and necessary arts of life; these have something peculiar in their construction, some difference, often indeed slight; but always clearly indicating that, whether better or worse fitted for the same purposes as those in use in other countries, the one did not serve as a model for the other."b

66

But the general form of chain pumps in China is that of a square tube or trunk made of plank; and of various dimensions acccording to the power employed to work them. Those that are portable, with one of which every peasant is furnished, are commonly six or seven inches in diameter, and from eight to ten feet in length. Some are even longer, for Van Braam, who was several years in China, and who, as a native of Holland, was a close observer of every hydraulic device, when speaking of them, remarks, that "they use them to raise water to the height of ten or twelve feet; a single man works this machine, and even carries it wherever it is wanted, as I have had occasion to remark several times in the province of Quangtong near Vampou."e A small wheel or roller is attached to each end of the trunk, over which an endless chain is passed. Pallets, or

It was preferred by the architect of Black Friars Bridge, London, to raise the water from the Caissons.

Embassy to China. Lon. 1798. Vol. iii, 102.

• Embassy of the Dutch E. I. Company. Lon. 1798. Vol. i, 75.

square pieces of plank, fitted so as to fill (like the piston of a common pump) the bore of the tube, are secured to the chain. When the machine is to be used, one end of the trunk is placed in the water, and the other rests on the bank over which it is to be raised. The upper wheel or roller is put in motion by a crank applied to its axle, and the pallets as they ascend the trunk, push the water that enters it before them, till it is discharged above. In machines of this description one half of the chain is always outside of the tube and exposed to view, but in others the trunk is divided by a plank, so as to form two separate tubes, one above another, and hence the chain rises in the lower one and returns down the upper. These pumps are represented as exceedingly effective, delivering a volume of water equal to the bore of the trunk. Whenever a breach occurs in one of their canals, or repairs are to be made, hundreds of the neighboring peasants are summoned to the work, and in a few hours will empty a large section of it by these machines.

When a pump is intended to raise a great quantity of water at once, it is made proportionably larger, and is moved by a very simple tread wheel; or rather by a series of wooden arms projecting from various parts of a lengthened axle, which imparts motion to the chain, as represented in the figure.

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These arms are shaped like the letter T, and the upper side of each is made smooth for the foot to rest on. The axle turns upon two upright pieces of wood, kept steady by a pole stretched across them. The machine being fixed, men treading upon the projecting arms, and supporting themselves upon the beam across the uprights, communicate a rotary motion to the chain, the pallets attached to which draw up a constant and copious stream of water. Another mode of working them, which Staunton observed only at Chu-san, was by yoking a buffalo, or other animal, to a large horizontal cog wheel, working into a vertical one, fixed on the

Chap. 17.]

Paternoster Pumps.

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same shaft with the wheel that imparts motion to the chain, as represented in figures 49 and 54. The description of this machine by Staunton is similar to that previously given by the missionaries, and they enumerate the various modes of propelling it which he has mentioned. But Nieuhoff, with the characteristic sagacity of his countrymen, noticed either these, or some other machines for the same purpose, propelled by wind. When

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speaking of the populous city of Caoyeu, and its environs, he observes, they boast likewise of store of windmills, whose sails are made of mats. The great product of the country consists of rice, which the peasant stands obliged to look after very narrowly, lest it perish upon the ground by too much moisture, or too much heat and drought. The windmills, therefore, are to draw out the water in a moist season, and to let it in as they think fit." That part of the country, he continues, is "full of such mills." Several of them are represented in a plate, but without showing the pumps moved by them.

These were very likely to elicit the notice of a Dutchman; for draining mills, worked by horses and wind, have been used in Holland since the 14th century. They consisted however principally of the noria and chain of pots.

It is uncertain when the chain pump was first employed in Europe; whether it was made known by Marco Paulo, Ibn Batuta, or subsequent travelers in China, or was previously developed and introduced into use, independently of any information from abroad. An imperfect machine is described by several old authors. This was a common pump log, or wooden cylinder placed perpendicularly in a well; its upper end reaching above the level to which the water was to be raised, and having a lateral spout, as in ordinary pumps, for the discharge. A pulley was secured to one side of the log near the lower orifice, and a drum or wheel above the upper one. One end of a rope was let down the cylinder, and after being passed over the pulley was drawn up on the outside, and both ends were then spliced or united over the drum. To this rope, a number of leathern bags or stuffed globular cushions were secured at regular disThe diameter of each was equal to the bore of the cylinder. Ribs were nailed across the periphery of the drum, and between these, the cushions were so arranged as to fall, in order to prevent the rope from slipping. When the drum was put in motion, the cushions entered in succession the lower orifice of the pump, (which was two or three feet below the surface of the water,) and pushed up the liquid before them, till it escaped through the spout.

tances.

Machines of this description were formerly employed in mines; chains of iron being substituted for the ropes, and sometimes globes of metal in place of the cushions. The latter are figured by Kircher in his Mundus Subterraneus, Tom. ii, 194. Among the earliest of modern authors who have described these pumps is Agricola. He has given five different figures of them, but they differ merely in the apparatus for working them, according to the power employed, whether of men, animals, or water. The following cut, No. 65 is from his De Re Metallica.' It exhibits two separate views of the lower end of the pump, showing the mode of attaching the pulley, and the passage of the rope and cushions over it. From the resemblance of the chains or ropes and cushions, to the rosary, or string of beads on which Roman catholics count their prayers, these machines

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Staunton, Vol. iii, 315. b Duhalde's China. Paris, 1735. Tom. ii, 66, 67.

Ogilvy's Translation. Lon. 1673, pp. 34, 85-and Histoire Générale. Amsterdam, 1749. Tom. viii, 81, 82.

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