Chapter II: Part 2

As the water is first raised into the basin, by means of machinery propelled by horses or oxen within the chamber, it may be asked, how are these animals conveyed to that depth in this tremendous pit, and by what means do they ascend? A spiral passage-way is cut through the rock, from the surface of the ground to the chamber, independent of the well, round which it winds with so gentle a descent, that persons sometimes ride up or down upon asses or mules. It is six feet four inches wide, and seven feet two inches high. Between it and the interior of the well, a wall of rock is left, to prevent persons falling into, or even looking down it (which in some cases would be equally fatal), except through certain openings or windows, by means of which it is faintly lighted from the interior of the well. The animals descend by this passage to drive the machinery that raises the water from the lower shaft into the reservoir or basin, from which it is again elevated by similar machinery and other oxen on the surface of the ground. In the lower shaft a path is also cut down to the water, but as no partition is left between it and the well, it is extremely perilous for strangers to descend.

NOTE.—However old and numerous wells with stairs in them may be,
most of the ancient ones were constructed without them; hence the
necessity of some mode of raising the water. From the earliest ages,
a _vessel suspended by a cord_, has been used by all nations—a device
more simple and more extensively employed than any other, and one
which was undoubtedly the germ of the most useful hydraulic machine
of the ancients. The figures shown on this and a few succeeding pages
are from the collection made by Ewbank—to whom reference has been
made in another portion of this work.

The square openings represented on each side of the upper shaft are sections of the spiral passage, and the zig-zag lines indicate its direction. The wheels at the top carry endless ropes, the lower parts of which reach down into the water; to these, earthenware vases are secured by ligatures (see A A) at equal distances through the whole of their length, so that when the machinery moves these vessels ascend full of water on one side of the wheels, discharge it into troughs as they pass over them and descend in an inverted position on the other side.

This celebrated production of former times, as will be perceived, resembles an enormous hollow screw, the center of which forms the well and the threads a winding stair-case around it. To erect of granite, a flight of “geometrical” or “well stairs,” two or three hundred feet high, on the surface of the ground, would require extraordinary skill, although in its execution every aid from rules, measures, and the light of day, would guide the workmen at every step; but to begin such a work at the top, and construct it _downwards_ by excavation alone, in the dark bowels of the earth, is a more arduous undertaking, especially as deviations from the correct lines could not be remedied; yet in Joseph’s well, the partition of rock between the pit and the passage-way, and the uniform inclination of the latter, seem to have been ascertained with equal precision, as if the whole had been constructed of cut stone on the surface. Was the pit, or the passage, formed first; or were they simultaneously carried on, and the excavated masses from both borne up the passage, are unanswered questions.

The extreme thinness of the partition wall, excited the astonishment of M. Jomard, whose account of the well is inserted in the second volume of Memoirs in Napoleon’s great work on Egypt. It is, according to him, but sixteen centimetres thick, [about six inches!] He justly remarks that it must have required singular care to leave and preserve so small a portion while excavating the rock from both sides of it. It would seem no stronger in proportion, than sheets of paste-board placed on edge, to support one end of the stairs of a modern built house, for it should be borne in mind, that the massive roof of the spiral passage _next the well_, has nothing but this film of rock to support it, or to prevent from falling, such portions as are loosened by fissures, or such, as from changes in the direction of the strata, are not firmly united to the general mass. But this is not all: thin and insufficient as it may seem, the bold designer has pierced it through its whole extent with semi-circular openings, to admit light from the well: those on one side are shown in the engraving.

Aqueducts, fountains, cisterns and wells, are in numerous instances the only remains of some of the most celebrated cities of the ancient world. Of Heliopolis, Syene and Babylon in Egypt; of Tyre, Sidon, Palmyra, Nineveh, Carthage, Utica, Barca, and many others. “The features of nature,” says Dr. Clarke, “continue the same, though works of art may be done away: the ‘beautiful gate’ of the Jerusalem temple is no more, but Siloah’s fountain still flows, and Kedron still murmurs in the valley of Jehoshaphat.” According to Chateaubriand, the Pool of Bethesda, a reservoir, one hundred and fifty feet by forty, constructed of large stones cramped with iron, and lined with flints embedded in cement, is the only specimen remaining of the ancient architecture of that city.

NOTE.—Roman wells are found in every country which that people
conquered. Their armies had constant recourse to them when other
sources of water failed. Pompey and Cæsar often preserved their
troops from destruction by having provided them. It was Pompey’s
superior knowledge in thus obtaining water, which enabled him to
overthrow Mithridates, by retaining possession of an important post.

NOTE.—The operation of this primitive device may be thus
described—Near the well or tank, a piece of wood is fixed, forked at
the top; in this fork another piece of wood is fixed to form a swape,
which is formed by a peg, and steps cut out at the bottom, that the
person who works the machine may easily get up and down. Commonly,
the lower part of the swape is the trunk of a tree; to the upper end
is fixed a pole, at the end of which hangs a leather bucket. A man
gets up the steps to the top of the swape, and supports himself by
a bamboo screen erected by the sides of the machine. He plunges the
bucket into the water, and draws it up by his weight; while another
person stands ready to empty it.

Ephesus, too, is no more; and the temple of Diana, that according to Pliny was 220 years in building, and upon which was lavished the talent and treasure of the east; the pride of all Asia, also one of the wonders of the world, has vanished, while the fountains which furnished the citizens with water, remain as fresh and perfect as ever. Cisterns have been discovered in the oldest citadels in Greece. The _fountains of Bounarbashi_ are perhaps the _only_ objects remaining that can be relied on, in locating the palace of Priam and the site of ancient Troy. And the well near the outer walls of the temple of the sun at Palmyra, will, in all probability, furnish men with water, when other relics of Tadmor in the wilderness have disappeared; a great number of the wells of the ancient world still supply man with water, although their history generally, is lost in the night of time.

We are now to examine the modes practised by the ancients, in obtaining water from wells. In all cases of moderate depth, the most simple and efficient, was to form an inclined plane or passage, from the surface of the ground to the water; a method by which the principal advantages of an open spring on the surface were retained, and one by which domestic animals could procure water for themselves without the aid or attendance of man.

But when in process of time, these became too deep for exterior passages of this kind to be convenient or practicable, the wells themselves were enlarged, and stairs for descending to the water, constructed within them.

HISTORICAL NOTE.—One of the most appalling facts that is recorded
of suffering from thirst occurred in 1805. A caravan proceeding
from Timbuctoo to Talifet, was disappointed in not finding water
at the usual watering places; when, horrible to relate, all the
persons belonging to it, two thousand in number, besides eighteen
hundred camels _perished by thirst_! Occurrences like this, account
for the vast quantities of human and other bones, which are found
heaped together in various parts of the desert. While the crusaders
besieged Jerusalem, great numbers perished of thirst, for the Turks
had filled the wells in the vicinity. Memorials of their sufferings
may yet be found in the heraldic bearings of their descendants. The
charge of a foraging party “for water,” we are told, “was an office
of distinction;” hence, some of the commanders on these occasions,
subsequently adopted _water buckets_ in their coats of arms, as
emblems of their labors in Palestine.

Wells with stairs by which to descend to the water, are still common. The inhabitants of Arkeko in Abyssinia, are supplied with water from six wells, which are twenty feet deep and fifteen in diameter. The water is collected and carried up a broken ascent by men, women and children. Fryer in his Travels in India speaks of “deep wells many fathoms underground, with stately stone stairs.” Near the village of Futtehpore, is a large well, ninety feet in circumference, with a broad stone staircase which is about thirty feet deep to descend to the water. The fountain of Siloam is reached by a descent of thirty steps cut in the solid rock, and the inhabitants of Libya, where the wells often contain little water, “draw it out in little buckets, made of the shank bones of camels.”

Wells with stairs are not only of very remote origin, but they appear to have been used by all the nations of antiquity. They were common chiefly, among the Greeks and Romans.

As a matter of interest some six or eight representations of the early forms of wells, have been introduced; but little need to be written relating to them—the cuts with the titles speak for themselves and also indicate their manner of use. (See note.)

_In Syria and Palestine_ at the present time the antique bucket and rope, in modified form, is still used in raising water from wells for irrigation. The buckets are attached to the ropes at regular intervals and pass over large drums going down empty and rising full. They discharge at the top into a large open trough, which conveys the water to the irrigating ditches.

A method much used where rivers are available is the wheel and bucket, in which the buckets are mounted on the rim of a large wheel which is of a diameter equal to the height to which the water is to be raised. The processes although extremely crude are well adapted to countries where labor is inexpensive as the running expense of the devices is very small.

NOTE.—The source from which many of these have been derived is
“_Eubank’s Hydraulics_,” to which work credit is gladly given for
nearly all the historical data so far used in this volume. The author
of the book named gave many years of research into the early records
of all relating to hydraulics and water machines and kindred subjects.

WATER-LIFTING INVENTIONS.

_The raising of water is one of the early arts_; beginning in ancient times with devices of the crudest form it has followed the progress of civilization with ever-increasing importance. In the present era, it demands engineering ability of the highest order and the finest of machinery.

Important epochs in the gradual inventions relating to pumps and hydraulics are: (1) The “force pump,” due to Ctesibius 200 B. C.; (2) the “double-acting pump,” invented by La Hire in 1718; (3) the “hydraulic ram,” by Whitehurst in 1772; (4) the “hydraulic press,” introduced by Joseph Bramah in 1802.

Most of the machines hitherto noticed, raise water by means of flexible cords or chains, and are generally applicable to wells of great depth. We now enter upon the examination of another variety, which, with one exception (the chain of pots), are composed of inflexible materials, and raise water to limited heights only.

In preceding machines, the “mechanical powers” are distinct from the hydraulic apparatus, _i. e._, the wheels, pulleys, windlass, capstan, etc., form no essential part of the machines proper for raising the water, but are merely employed to transmit motion to them; whereas those we are now about to describe, are made in the form of levers, wheels, etc., and are propelled as such.

The Roman Screw delineated upon the opposite page, if not the earliest hydraulic engine that was composed of _tubes_, or in the construction of which they were introduced, is certainly the oldest one known of that description; in its mode of operation it differs essentially from all other ancient tube machines; in the latter the tubes merely serve as conduits for the ascending water, and as such are at rest; while in the screw it is the tubes themselves in motion that raises the liquid.

Fig. 73 represents one of the earliest forms of _a double gutter_, placed across a trough or reservoir designed to receive the water. A partition is formed in the center, and two openings made through the bottom on each of its sides, through which the water that is raised escapes. The machine is worked by one or more men, who alternately plunge the ends into the water, and thus produce a continuous discharge.

Sometimes, openings are made in the bottom next the laborers, and covered by flaps, to admit the water without the necessity of wholly immersing those ends; machines of this kind probably date from remote antiquity; they are obviously modifications of the _Jantu_ of Hindostan and other parts of Asia. The jantu is a machine extensively used in parts of India, to raise water for the irrigation of land, and is thus described: “It consists of a hollow trough of wood, about fifteen feet long, six inches wide, and ten inches deep, and is placed on a horizontal beam lying on bamboos fixed in the bank of a pond or river.

One end of the trough as shown in the figure rests upon the bank where a gutter is prepared to carry off the water, and the other end is dipped in the water, by a man standing on a stage, plunging it in with his foot. A long bamboo with a large weight of earth at the farther end of it, is fastened to the end of the jantu near the river, and passing over the gallows, poises up the jantu full of water, and causes it to empty itself into the gutter. This machine raises water three feet, but by placing a series of them one above another, it may be raised to any height, the water being discharged into small reservoirs, sufficiently deep to admit the jantu above, to be plunged low enough to fill it;” water is thus conveyed over rising ground to the distance of a mile and more. In some parts of Bengal, they have different methods of raising water, but the principle is the same.

_The Tympanum._ This is a water raising current wheel originally made in the form of a drum, hence the name. It is now a circular open frame wheel, fitted with radial partitions as shown in Fig. 74, so curved as to point upward on the rising side of the wheel and downward on the descending side. The wheel is so suspended that its lower edge is just submerged and is turned by the current (or by other power), the partitions scooping up a quantity of water which, as the wheel revolves, runs back to the axis of the wheel where it is discharged; or it may discharge at some point of the periphery; while one of the most ancient forms of water lifting machines it is still used in drawing works.

A little study of the figure (74) will explain its operation.

S, is the shaft; G G, the gutters; A, a trough to take away the water. The arrow indicates the direction in which the wheel turns; each gutter, as it revolves scoops up a portion of water and elevates it, till by the inclination to the axle, it flows towards the latter, and is discharged through one end of it.

The prominent defect of the tympanum arises from the water being always at the extremity of a radius of the wheel, by which its resistance increases as it ascends to a level with the axis, being raised at the end of levers which virtually lengthen till the water is discharged from them; this has been remedied by making the arms curving as shown in the _Scoop Wheel_ (Fig. 75.) As this revolves in the direction of the arrow the extremities of the partitions dip into the water and scoop it up and as they ascend discharge it into a trough placed under one end of the shaft which is hollowed into as many compartments as there are partitions or scoops.

Fig. 76 represents a sectional view of _an improved tympanum_; this was invented by De La Faye; the illustration will be readily understood. As shown in Figs. 74 and 75 the wheel is driven by the current of a stream impinging upon what in later times came to be known as boards or floats on the circumference of the wheel.

Within the enclosure are arranged four scrolls of suitable proportions, dipping the water, at one end, and emptying it out at the center of the wheel as more clearly shown in Figs. 74 and 75.

_The Noria or Egyptian Wheel._ The tympanum has been described as an assemblage of gutters, and the _Noria_ may be considered as a number of revolving swapes. It consists of a series of poles united like the arms of a wheel to a horizontal shaft. To the extremity of each, a vessel is attached which fills as it dips into the water, and is discharged into a reservoir or gutter at the upper part of the circle which it describes. Hence, the former raises water only through half a diameter, while this elevates it through a whole one. (Fig. 77.)

The Chinese make the noria, in what would seem to have been its primitive form, and with an admirable degree of economy, simplicity, and skill. With the exception of the axle and two posts to support it, the whole is of bamboo, and not a nail used in its construction. Even the vessels, are often joints of the same, being generally about four feet long and two or three inches in diameter. They are attached to the poles by ligatures at such an angle, as to fill nearly when in the water, and to discharge their contents when at, or near the top.

The periphery of the wheel is composed of three rings of unequal diameter and so arranged as to form a frustrum of a cone. The smallest one, to which the open ends of the tubes are attached, being next the bank over which the water is conveyed. By this arrangement their contents are necessarily discharged into the gutter as they pass the end of it. When employed to raise water from running streams they are propelled by the current in the usual way—the paddles being formed of woven bamboo. The sizes of these wheels, vary from twenty to seventy feet in diameter; some raise over three hundred tons of water in twenty-four hours. A writer mentions others which raise a hundred and fifty tons to the height of forty feet during the same time.

NOTE.—The mode of constructing and moving the noria by the Romans,
is thus described by Vitruvius, who lived about the beginning of
the Christian Era. “When water is to be raised higher than by the
tympanum, a wheel is made round on axis of such a magnitude as the
height to which the water is to be raised requires. Around the
extremity of the side of the wheel, square buckets cemented with
pitch and wax are fixed; so that when the wheel is turned by the
walking of men, the filled buckets being raised to the top and
turning again toward the bottom, discharge of themselves what they
have brought into the reservoir.”

_The Persian Wheel._ Two prominent defects exist in the noria. First, part of the water escapes after being raised nearly to the required elevation. Second, a large portion is raised _higher_ than the reservoir placed to receive it, into which it is discharged after the vessels begin to descend; to obviate this _the Persian wheel_ was devised.

The vessels in which the water is raised, instead of being fastened to the rim, or forming part of it, as in the preceding figures, are suspended from pins, on which they turn, and thereby retain a vertical position through their entire ascent; and when at the top are inverted by their lower part coming in contact with a pin or roller attached to the edge of the gutter or reservoir, as represented in the figure. By this arrangement no water escapes in rising, nor is it elevated any higher than the edge of the reservoir; hence, the defects in the noria are avoided. It is believed, to have been used in Europe ever since the time of the Romans.

GAINING AND LOSING BUCKETS.

In the latter part of the Sixteenth, or beginning of the Seventeenth Century a machine which is entitled to particular notice on account of its being, as claimed, the first one of the kind to be _self-acting_, for raising water was in use in Italy. It is ascribed to Gironimo Finugio who put one in operation at Rome in 1616.

Between the illustration and the following description its operation may be clearly understood. On a pulley S, are suspended by a rope two buckets A and B, of unequal dimensions. The smaller one B, is made heavier than A when both are empty, but lighter when they are filled. It is required to raise by them part of the water from the spring or reservoir E, into the cistern Z. As the smaller Bucket B, by its superior gravity, descends into E, (a flap valve in its bottom admitting the water), it consequently raises A into the position represented in the figure. A pipe F, then conveys water from the reservoir into A, the orifice or bore of which pipe is so proportioned, that both vessels are filled _simultaneously_. The larger bucket then preponderates, descending to O, and B at the same time rising to the upper edge of Z, when the projecting pins O O, catch against others on the lower sides of the buckets, and overturn them at the same moment. The bails or handles are attached by swivels to the sides, a little above their center of gravity. As soon as both buckets are emptied, B again preponderates, and the operation is repeated without any attendance, so long as there is water in E and the apparatus continues in order.

In Moxon’s machine, the buckets were filled by two separate tubes of unequal bore; the orifices being covered by valves to prevent the escape of water while the buckets were in motion; these valves were opened and closed by means of cords attached to the buckets. The efflux through F in the figure, may easily be stopped as soon as A begins to descend, by the action of either bucket on the end of a lever attached to a valve, or by other obvious contrivances. The water discharged from A, runs to waste through a channel provided for that purpose. These machines are of limited application, since they require a fall for the descent of A, equal to the elevation to which the liquid is raised in B. They may however be modified to suit locations where a less descent only can be obtained. Thus, by connecting the rope of B to the periphery of a large wheel, while that of A is united to a smaller one on the same axis, water may be raised higher than the larger bucket falls, but the quantity raised will of course be proportionally diminished. In the face of these securing advantages it has fallen into disuse; it was much too complex and cumbersome, and of too limited application.

The principle of self-action in all these machines is no modern discovery, for it was described by Hero of Alexandria, who applied it to the opening and closing the doors of a temple, and to other purposes.

THE PULLEY AND WINDLASS.

In those vast periods preceding the dawn of history, water was _as heavy and as necessary_ for the use of mankind and animals as it is to-day; the toil and labor in securing it must indeed have been hard. Doubtless, the first inventions of the primitive man were first made—perhaps, after weapons of defence—to relieve himself of the painful endeavor of supplying the precious liquid.

There are reasons which render it probable that the _single pulley_ was devised to raise water and earth from wells; the latter are not only of the highest antiquity but they are the only known works of man in early times in which the pulley could have been required or applied. That it preceded the invention of ships and the erection of lofty buildings of stone, is all but certain; but for what purpose, save for raising of water, the pulley could have been previously required it would be difficult to divine; it seems to have been the first addition made to those primitive implements, the cord and the bucket.

By it _the friction of the rope_ in rubbing against the curb and the consequent loss of a portion of the power expended in raising the water, were avoided, and by it also a beneficial _change in the direction of the power_ was attained; instead of being exerted in an ascending direction, it is applied more conveniently and efficiently in a descending motion as shown in the various figures and illustrations in the preceding pages.

But the grand advantage of the pulley in the early ages was this:—by it the vertical direction in which men exerted their strength, could be directly changed into a horizontal line, by which change _animals could be employed_.

The wells of Asia, frequently varying from two to three, and even four hundred feet in depth, obviously required more than one person to raise the contents of an ordinary sized vessel; and where numbers of people depended on such wells, not merely to supply their domestic wants, but for the purposes of irrigation, the substitution of animals in place of men to raise water, became a matter almost of necessity, and was certainly adopted at a very early period. In employing an ox for this purpose, the simplest way and one which deviated the least from their accustomed method, was merely to attach the end of the rope to the yoke, after passing it over a pulley fixed sufficiently high above the mouth of the well, and then driving the animal a distance equal to its depth, in a direct line from it, when the bucket charged with the liquid would be raised from the bottom.

Although it may never be known to whom the world is indebted for the _windlass_, there are circumstances which point to the construction of wells and raising of water from them, as among the first uses to which it as well as the pulley, was applied. The windlass possesses an important advantage over the single pulley in lifting weights, or overcoming any resistance since the intensity of the force transmitted through it can be modified, either by varying the length of the crank, or the circumference of the roller on which the rope is coiled. Sometimes a single vessel and rope, but frequently two, are employed as shown in several of the preceding illustrations; one of these is the _Chinese Windlass_. This furnishes the means of increasing mechanical energy to almost any extent, and as it is used to raise water from some of those prodigiously deep wells already noticed, a figure of it, page 47, has been inserted. The roller consists of two parts of unequal diameters, to the extremities of which the ends of the rope are fastened on opposite sides, so as to wind round both parts in different directions. As the load to be raised is suspended to a pulley, every turn of the roller raises a portion of the rope equal to the circumference of the thicker part, but at the same time lets down a portion equal to that of the smaller; consequently the weight is raised at each turn, through a space equal only to half the difference between the circumferences of the two parts of the roller. The action of this machine is therefore slow, but the mechanical advantages are proportionately great.

The _fusee windlass_ is shown in Fig. 79. This is an early invention designed to overcome in a mechanical method the greater weight which the rope hung at its extremity has, as compared to what it is when nearly wound up. At the bottom of the well the rope then being at its heaviest period is wound upon the small end of the fusee; and as the length diminishes it coils round the larger part. (See Fig. 79), which is however inaccurately drawn—as the bucket is at the top of the well; it should have been represented as suspended from the large end of the fusee.

The value of a device like this will be appreciated when the great depth of some wells is considered and the consequent additional weight of the chains. In the fortress of Dresden is a well eighteen hundred feet deep; at Augustburgh is a well in which half an hour is required to raise the bucket; and at Nuremburgh another, sixteen hundred feet deep. In all these, the water is raised by chains, and the weight of the one used in the latter is stated to be upwards of a ton.

_The tympanum and noria_ in all their modifications have been considered as originating in the gutter or _jantu_, and _the swape_; while the machine we are now to examine is evidently derived from the primitive _cord and bucket_. The first improvement of the latter was the introduction of a pulley or sheave over which the cord was directed—the next was the addition of another vessel, so as to have one at each end of the rope, and the last and most important consisted in uniting the ends of the rope, and securing to it a number of vessels at equal distances through the whole of its length—and the _chain of pots_ was the result. (See Fig. 80.)

The general construction of this machine will appear from an examination of those which are employed to raise water from Joseph’s well at Cairo, represented on page 45. Above the mouth of each shaft a vertical wheel is placed, over which two endless ropes pass and are suspended from it. These are kept parallel to, and at a short distance from each other, by rungs secured to them at regular intervals, so that when thus united, they form an endless ladder of ropes. The rungs are sometimes of wood, but more frequently of cord like the shrouds of a ship, and the whole is of such a length that the lowest part hangs two or three feet below the surface of the water that is to be raised. Between the rungs, earthenware vases (of the design shown at A A) are secured by cords round the neck, and also round a knob formed on the bottom for that purpose.

WHEEL AND AXLE.

In all the preceding machines the roller is used in a _horizontal_ position; but at some unknown period of past ages, another modification was devised, one by which the power could be applied at any distance from the center. Instead of placing the roller as before, over the well’s mouth, it was removed a short distance from it, and secured in a vertical position, by which it was converted into the wheel or capstan. One or more horizontal bars were attached to it, of a length adapted to the power employed, whether of men or animals; and an alternating rotary movement imparted to it, as in the common wheel or capstan, represented in the figure. It appears that machines of this kind, and worked by _men_ were common in Europe previous to, and at the time he wrote. Sometimes the shaft was placed in the edge of the well, so that the person who moved it walked round the latter, and thus occupied less space.

SUCCESSIVE INVENTIONS.

With the wide acceptance in practical use of the Duplex steam pump, may be dated the beginning of the modern inventive period of pumping machinery; this introduction of the Duplex pump was only one of five successive advances which it were well for the student to memorize:

1. The Cornish,

2. The Rotative,

3. The Direct Acting,

4. The Duplex, and

5. The Compounded Steam Pump.

The Cornish engines have been alluded to in connection with the Newcomen engine. Probably no large pumping engines in the past have held, and deservedly so, as high repute as have the Cornish engines when used for deep mine pumping. Their construction, with the rude appliances at hand, is not only a marvel but as well a high tribute to the ingenuity of those who designed them and to the skill of the workmen who built them. A rather full illustrated description of this almost unexcelled machine will be found later on in the book.

_The next class of large steam pumping-engines which have played an important part in the history of hydraulic engineering may be grouped together as “rotative engines.”_ What is here meant by the term “rotative” is engines in which there are parts which make complete and continuous rotary motion and in which are used, in some way or another, shafts, cranks and fly-wheels.

These engines vary greatly in their design and in the details of their construction. They are of varying sizes, including some of the largest and most expensive in the world. As a general thing they are employed in supplying towns and cities with water, and in some cases freeing shallow mines of water. The application of the power of the steam used in the steam cylinders in this class of engines to drive the plungers or pistons in the pumps, varies greatly, both as to the general design upon which they are built, and in the detail of their construction. In some instances it is through the use of long or short beams or bell cranks, sometimes through gearing, and occasionally through the plunger or piston of the pump direct; but in all cases the limit of the stroke of the steam piston, and of the pump plunger, is governed by a crank on a revolving shaft.

Attached to the revolving shaft is _a fly-wheel_ of greater or less diameter and weight, which, in addition to assisting the crank to pass the center at each end of its stroke, _is employed to store up at the beginning of each stroke of the steam piston, whatever excess of power or impulse there may be imparted to it, beyond that required to steadily move the water column, and to give out again, toward the latter part of the stroke, when the power of the steam is of itself below that required to move the water column, the power previously stored in it_. In this respect the function of a revolving fly-wheel on a rotative engine is the same as is the weighted plunger in the Cornish engine; both being used for the purpose of permitting the steam to be cut off at a portion of its stroke in the steam cylinder, and expanded during the rest of the stroke.

In short, these devices, as employed in both the classes of pumping engines described, were used in order that the best economy in the consumption of steam by means of early cutoff and a high grade of expansion, might be attained.

The succeeding class of pumps to be described, driven by steam are _direct acting steam-pumps_.

What is here meant as “direct-acting,” is a steam-driven pump in which there are no revolving parts, such as shafts, cranks and fly-wheels; _pumps in which the power of the steam in the steam cylinder is transferred to the piston or plunger in the pump in a direct line_, and through the use of a continuous rod or connection. (Fig. 82.)

_The introduction of the direct-acting steam-pump marked a point of deviation_, and it entered the field almost without a rival, and at a time when economy was overshadowed by its convenience.

In the brief description given of these three most prominent classes of pumping engines, no attempt has been made to describe any of the peculiarities of their general construction, beyond what was necessary to describe their action and the principles upon which they operate.

In pumps of this construction there are no weights in the moving parts other than that required to produce sufficient strength in such part for the work they are expected to perform, and, as there is consequently no opportunity to store up power in one part of the stroke, to be given out at another, it is impossible to cut off the steam in the steam cylinder during any part of its stroke. The uniform and steady action of the direct-acting steam-pump is dependent alone on the use of a steady uniform pressure of steam through the entire stroke of the piston against a steady, uniform resistance of water pressure in the pump; the difference between the power exerted in the steam cylinders over the resistance in the pump governing the rate of speed at which the piston or plunger of the pump will move. The length of the stroke of the steam piston, within the steam cylinders of this class of pumps, is limited and controlled alone by the admission, suppression and release of the steam used in the cylinders.

NOTE.—Up to the introduction of the direct-acting steam pump, all
the other pumping machinery of the world then in use was the outcome
of evolution. It had been developed by slow stages, in which one
engineer after another aided by the experience of others and of
his own, supplemented by his inventive faculties, added here and
there slight improvements to which other engineers, with increased
experience, were enabled to add still other improvements, so that
each new engine constructed under more favorable circumstances, and
with increasing expenditures, was supposed to excel all previously
built; until at this time we have, as it is fair to suppose, pumping
engines which combine all the wisdom of the past, and which leave
little or no room for further improvements in their respective
classes.

The history of the _Direct-Acting Steam Pump_ differs from all others from the fact that it was the invention of one man, and was in the main perfected during his lifetime. It was so strikingly different from all that had preceded it, that there was nothing in the way of precedent, either in ancient or modern practice, of which the inventor could avail himself by which to aid or guide him to success.

The date of the first patent on these pumps was September 7, 1841. It was issued on a small pump used for supplying feed water to a steam boiler, and consisted of one steam cylinder connected to a force pump, and so arranged that by the use of levers, trips, springs, and other connections between the piston rod and the slide valve, the movement of the piston rod controlled the movements of the slide valve to an extent that not only regulated the length of the stroke of the piston, but reversed its motion. This pump was placed alongside of the steam boiler, and was so connected by means of pipes and levers and floats within the boiler, that when the water fell below the proper level in the boiler, it would start the pump, and stop it when the water rose too high.

NOTE.—At the head of a list consisting of two names only, who, on the
foremost pages of “The American Society of Mechanical Engineers,”
are recorded as the “Honorary Members in Perpetuity” of that large
society, and standing as well at the head of that long and increasing
list of members who have accomplished their work on earth, may be
seen the name of _Henry Rossiter Worthington_, the inventor and
original builder of the “direct-acting steam pump.”

Feeling how incomplete was an invention which did not provide against the intermittent action of the pump, Mr. Worthington devoted much time and study to correct this trouble, and a few years later he brought out an improved pump which, in its simplicity of parts, certainty of action, and cheapness of construction more than rivaled the original invention itself. This pump is now universally known as the “_Direct-Acting Duplex Steam Pump_.”

In the main, the construction of the steam ends and the water ends of the duplex pump differs but slightly from those of the single-acting pump, but the mechanism which operates the steam valves is different, and the effect on the water column was marvelously different; the principle upon which it operates is this:

Two pumps of similar construction are placed side by side, a lever attached to the piston rod of each pump connects to the slide valve of the opposite steam cylinder; thus the movement of each piston, instead of operating its own slide valve as in the single pump, operates the slide valve of the opposite cylinder. The effect of this arrangement is, that as the piston or plunger of one pump arrives near the end of its stroke, the plunger or piston of the other begins its movement, thus alternately taking up the load of the water column, producing a regular, steady, onward flow of water, without the unusual strains induced by such a column when suddenly arrested or started in motion.

While the “duplex steam pump” overcame one of the greatest objections to the former single pump, there still remained in this class of pumping machinery one other difficulty. It did not use steam expansively.

This not only debarred it from competing with other engines where a large quantity of water was required to be raised, and where the cost of fuel was an item of importance, but as well prevented the pump from taking rank among the hydraulic appliances required in supplying towns and cities.

This objection was one which seemed insurmountable, steam in them could not be used economically. Applied to the propulsion of the plunger or piston of this pump it must be of sufficient quantity, and pressure, to overcome the height of the column of water on the pump, together with its friction through the pump and its connections, _at the very beginning of the stroke_; and it must be maintained, both as to its volume, and its pressure up to the very last part of the stroke. Any diminution, either of volume or pressure, during any part of the stroke would simply bring the pump to a stop. This apparent inability to cut off the steam in the steam cylinder, and to complete the stroke of the pump by the aid of the steam remaining in the cylinder, and by its expansive force, had debarred this pump from coming into general use for large water works. How this, the only remaining objection to their use for such purposes, was overcome, forms an interesting chapter in the history of the “_Direct-Acting Steam Pump_.”

It was when this question had assumed a most formidable, importance, that the principle of _using steam in compound steam engines_ had engaged the careful consideration of the most eminent engineers of this and other countries; _its adjustment to the Duplex pumps was made_, and while it was easily done, owing to their peculiar construction, its application produced a most wonderful result in their working, and their speedy introduction for water works use.

NOTE.—At this time the man who had invented and built the little
steam pump for the canal boat, who had watched its growth and
development, supplemented one device after another to help it on
through the trial period of its existence, had merged it at last
into the dual or duplex stage of its advancement, had added to it
the compound feature, had seen it expanding in size and importance
until, growing up and out of the day of small things, it had come to
take its well-earned place alongside those old and massive machines
whose invention and origin was lost amid the musty records of the
past—it was, at this time, and of which any man might well have been
proud, that his lifelong labors came to an end Dec. 18., 1880, at the
Everett House, New York City.

ELEMENTARY
HYDRAULICS

ELEMENTARY HYDRAULICS.

There are three physical states or conditions of matter, which are the _solid_, _liquid_ and _gaseous_, which in this connection apply to Ice, Water and Steam. _A solid_ offers resistance both to change of shape and to change of bulk.

_A Fluid_ offers no resistance to change of shape. Again fluids can be divided into _liquids_ and vapors or gases. Water is the most familiar example of a liquid. A liquid can be poured out in drops while a gas or vapor flows in a stream or streams.

_Gas_ is a term at first used as meaning the same as the name _air_, but is now restricted to fluids supposed to be permanently elastic, as oxygen, hydrogen, etc., in distinction from vapor such as steam which become liquid upon a reduction of temperature.

It is important to note that experiment proves that every vapor becomes a gas at a sufficiently high temperature or low pressure, while, on the other hand, every gas becomes a vapor at sufficiently low and high pressures. In present popular usage the term gas applies to any substance in the aeriform elastic condition.

_Hydraulics_ is that branch of science or of engineering which treats of the motion of liquids, especially of water and of the laws by which it is regulated.

As a science, hydraulics includes _hydrodynamics_ or the principles of mechanics applicable to the motion of water.

As a branch of engineering, hydraulics consists in the practical application of the mechanics of fluids, to the control and management of water, with reference to the wants of man, including water works, hydraulic machines, pumps, water wheels, etc.

The term hydraulics, so familiar in daily use, is formed from two Greek words meaning: 1, water; 2, a pipe; hence, it will be observed with interest how close the original meaning follows the development of the science in its practical adaptation; there is always the “pipe” or holding vessel and the “water” or its equivalent.

From the same elementary word meaning water, in the Greek language, has been formed very many other words in common use, for example hydrophobia, hydrogen, hydrant, hygrometer, etc., as well as the following:

_Hydromechanics_ is that branch of natural philosophy which treats of the mechanics of liquid bodies, or in other words, of their laws of equilibrium and motion. Hydromechanics comprises properly those phenomena of liquids by which these bodies differ from solids or from bodies at large; hence, its foundation is laid in the properties that distinguish the liquid from other states of bodies, viz.: the presence of cohesion, with great mobility of parts, and perfect elasticity.

_Hydrostatics_ is that branch of science which relates to the pressure and equilibrium of non-elastic fluids, as water, mercury, etc.; thus, the hydrostatic press is a machine in which great force with slow motion is action communicated to a large plunger by means of water forced into the cylinder in which it moves, by a forcing pump. _Statics_ treats of forces that keep bodies at rest or in equilibrium, the water through which the force operates in the hydrostatic press always remaining at rest serves as a good illustration.

_Pneumatics_ is that branch of science, which relates to air, or gases in general or their properties; also of employing (compressed) air or other gas as a motive power. The use of pneumatic pumping machinery is constantly increasing, especially of the direct pressure types; under the section of this work relating to Air Pumps additional data will be presented.

_Hydropneumatics_ is defined as involving the combined action of water and air, or gas, as shown, for example, in the hydropneumatic accumulator. The word is a compound formed of the Greek words meaning water and air.

_Semi-liquids._ All the results stated in reference to water are further modified in those semi-liquids which have greater or less viscidity, as pitch, syrup, fixed oils, etc. Viscosity may be defined as the quality of flowing slowly, thus the viscosity of such liquids as have been named is very great as compared with that of a mobile liquid like alcohol.

HYDRODYNAMICS.

_Water, considered from a chemical standpoint_, is a compound substance consisting of hydrogen and oxygen, in the proportion of two _volumes_ of the former gas to one volume of the latter; or _by weight_ it is composed of two parts of hydrogen united with sixteen parts of oxygen. It should be noted that the union of these two gases is effected by _chemical action_ and not by _mechanical mixture_. Pure water is transparent, inodorous and tasteless.

Under ordinary conditions water passes the liquid form only at temperatures lying between 32° F. and 212° F.; it assumes a solid form, that of ice or snow at 32° F., and it takes the form of vapor or steam at 212° F.

_There are four notable temperatures for water_, namely:

32° F., or 0° C. = the freezing point under one atmosphere.
39°·1 or 4° = the point of maximum density.
62° or 16°·66 = the standard temperature.
212° or 100° = the boiling point, under one atmosphere.

The temperature 62° F. is the temperature of water used in calculating the specific gravity of bodies, with respect to the gravity or density of water as a basis, or as unity.

_Weight of one cubic foot of Pure Water._

At 32° F. = 62·418 pounds.
At 39°·1. = 62·425 „
At 62° (Standard temperature) = 62·355 „
At 212° = 59·640 „

The weight of a cubic foot of water is, it may be added, about 1000 ounces (exactly 998·8 ounces), at the temperature of maximum density.

The weight of a cylindrical foot of water at 62° F. is 48·973 pounds.

_Weight of one cubic inch of Pure Water._

At 32° F. = ·03612 pound, or 0·5779 ounce.
At 37°·1 = ·036125 „ „ 0·5780 „
At 62° = ·03608 „ „ 0·5773 „ or 252·595 grains.
At 212° = ·03451 „ „ 0·5522 „

The weight of one cylindrical inch of pure water at 62° F. is ·02833 pounds, or 0·4533 ounce.

_Volume of one pound of Pure Water._

At 32° F. = ·016021 cubic foot, or 27·684 cubic inches.
At 39°·1 = ·016019 „ „ 27·680 „
At 62° = ·016037 „ „ 27·712 „
At 212° = ·016770 „ „ 28·978 „

The volume of one ounce of pure water at 62° F. is 1·732 cubic inches.

The weight of water is usually taken in round numbers, for ordinary calculations, at 62·4 lbs. per cubic foot, which is the weight at 52°·3 F.; or it is taken at 62-1/2 lbs. per cubic foot.

Salt water boils at a higher temperature than fresh water owing to its greater density, and because the boiling point of water is increased by any substance that enters into chemical combination with it. The density of water decreases as the temperature increases, since heat destroys cohesion and expands the particles, causing them to occupy greater space, where precision is not required; the pressure on a square foot at different ocean depths are approximate, in the following

TABLE.

Depth in feet. | Pressure on sq. foot.
===============+======================
8 | 500 lbs.
16 | 1000 „
24 | 1500 „
32 | 2000 „
40 | 2500 „
48 | 3000 „
56 | 3500 „
64 | 4000 „
72 | 4500 „
80 | 5000 „
88 | 5500 „
96 | 6000 „
---------------+----------------------

1 mile, or 5,280 feet, 330,000 lbs.
5 miles, 1,650,000 „

This table is based upon an allowance of 62-1/2 lbs. of water to the cubic foot, thus 8 feet × 62-1/2 = 500, etc.

HYDRAULIC DATA.

_Water is practically non-elastic._ A pressure of 30,000 lbs. to the square inch has been applied and its contraction has been found to be less than one-twelfth. Experiment appears to show that for each atmosphere of pressure it is condensed 47-1/2 millionth of its bulk.