PUMPS AND PUMPING MACHINERY fits closely in the air cylinder. Therefore, the pressure per square inch on the accumulatorram and also in the compensating cylinders is equal to the pressure of the air in the air cylinder per square inch multiplied by the difference between the area of the air piston and that of the accumulator-ram. It is a matter of calculation and construction, which varies according to the particular service for which a pumping engine is designed; while the pressure in the air cylinder is controlled by the pressure in the main delivery pipe with which the air chamber is connected. The effect of this attachment on the successful operation of high duty pumping engines may be briefly described as follows: At the beginning of the outward stroke of the pump plunger-rod, the compensating cylinders point inward toward the pump, with their rams at an acute angle with the plunger-rod, and op 11 For the sake of economy in floor space most high-duty pumps are built in the upright or vertical form, the steam sylinders at the top, and the pump cylinders below. With the exception of the Worthington, which still remains of tandem design, the high, intermediate and low pressure steam cylinders are set side by side in a rank. With the same exception also, most of the high-duty pumps are built to work on a crank shaft carrying fly-wheels, some of which are enormously heavy; weighing, for instance, in the Holly waterworks pumps up to 32 tons each, and each pump carrying two such fly-wheels. The term "duty represents the work done by a steam pumping engine expressed in millions of pounds of water lifted to the height of one foot by the consumption of 100 pounds of coal, 1,000 pounds of dry steam, or by posing its advance with the full pressure of the accumulator load. As the plunger-rod advances outward, the angle between itself and the ram is increased gradually to 90 degrees. The rams recede into their cylinders, and their pressure against the rod is decreased until the pump plunger-rod has reached the halfway point of its stroke, when the rams will be at right angles to it-a position in which they neither retard nor advance its movement. As the pump plunger-rod continues on its outward stroke, the angle between itself and the rams :s again decreased, but now the rams, pointing in the opposite direction, emerge from their cylinders, and exert their power to push the plunger onward to the termination of its outward stroke. It is obvious that similar conditions obtain during the return stroke of the plunger, the effect of the action being to store up power during the early part of the stroke, either forward or backward, when the steam is under its greatest pressure, and to release it at the end of the stroke, when the pressure in the steam cylinder has fallen away to its lowest point, that is, below the amount necessary to move the plunger against the pressure of the water column. The Worthington pumps with this attachment and the use of multiple expansion steam engines operate with absolute freedom from the noise and shock so characteristic of the crank and fly-wheel machines. 1,000,000 British thermal units (B. T. U.). On account of the variable quality of coal, the two last-named constants give the more correct results, and are the values now employed in determining the comparative efficiencies of pumping engines, which range from 20.6 per cent for the high-duty engines, to about 0.13 per cent for jet pumps. During the last 100 years, the development of pumping engines has increased their duty from about 5,000,000 foot-pounds for the Newcomen atmospheric engines, to over 170,000,000 foot-pounds for the crank and fly-wheel, or duplex triple expansion pumping engines of the latest construction. Somewhat of an idea of the difference between the first duplex Worthington pumping engines and those of their latest construction may be obtained by comparing that of the Charlestown, Mass., waterworks, with its ca pacity of 5,000,000 gallons per day, with the installation at the Baltimore, Md., waterworks high service pumping station, which delivers 18,000,000 gallons per day. The former gave a duty of 70,000,000 foot-pounds, while the duty of the latter exceeded 140,000,000 foot-pounds per 1,000 pounds of dry steam. Hydraulic pressure pumps are designed as a rule for driving water into an accumulator, whence it may be drawn for power service in mains, or for use in hydraulic presses (q.v.), hydraulic cranes (q.v.), and similar machines. The pumps which do this exceptionally heavy work are of the plunger type of direct-acting pumps, the plungers being very small-about one and one-quarter inches in diameter and of six-inch stroke, while the steam cylinders are of the usual size. The high and low pressure cylinders are commonly placed side by side and work upon a crank-shaft which carries a heavy fly-wheel. These pumps work up to 4,000 or 5,000 pounds per square inch. In all reciprocating pumps, valves play an essential part. In the simplest forms the valves are made of leather or rubber, and are fixed in position by a hinge on the edge, generally, for the larger sizes, having a metal form which prevents too great relaxing. They are made in a great variety of forms and operate in response to certain pressure, or, as in the case of the Reidler valve, by mechanical means. They consist essentially of a "valve seat," to which the "disc" or valve proper is attached, the "stem" which controls the lift of the disc and prevents its displacement from the seat, the "cover plate," and the "valve spring," introduced in some forms to take up slacks. When a valve is required only to prevent the back pressure or a reverse flow, a single flap or check valve is used. In large pumps a number of small valves are employed, equal in aggregate area to a single large valve of sufficient size to allow the passage of the whole flow, thus preventing injurious shocks when the valves are opened and closed suddenly, as all of the smaller valves do not close simultaneously but each as its critical pressure supervenes. Excepting the discs, all the other parts of a valve are made of bronze, while metallic ball and cone valves are extensively used in deep well pumps. A detailed description of the more commonly used valves will be found in the special article under the title VALVE. History. The raising of water for economical purposes dates back to the remotest periods. It is not easy to determine just when mechanical appliances worthy to be classed as pumps first made their appearance, and it has been the custom of some writers to dignify the common water-pail by the name of pump if only it were lifted by mechanical means- - as, for example, with the old-time well-sweep. In this connection mention has been made of the "shadoof," of Egypt, authentically recorded as having been in use over 1,500 years B.C., in the time of the Pharaohs, a period antedating the Exodus. It is still used extensively in that region, myriads of them lining the banks of the Nile, where they are worked unceasingly by relays of men, without intermission, day and night. It is also used extensively all over Hindustan, where it is called the "picotah." In fact, the "sweep" in some form is used extensively in all of the Oriental countries from Asia Minor to China and Japan and also in Mexico and South America, for domestic purposes and for the irrigation of land. For the latter purpose, however, it was superseded in India by the "jantu," an oscillating wooden trough involving the same principle, that of the lever, and worked by hand. The "windlass and bucket" arrangements operated by cranks or by tread-wheels, the latter worked by men or animals, appear to have followed the "sweep," first among the Chinese, and later among the earliest Greeks and Romans. About the beginning of the Christian Era, Vitruvius, a Roman engineer, described a number of pumping machines involving a rotary principle -the "tympanum," "noria," "chain of buckets or pots,' the "screw" and the "pump." The tympanum consisted of a series of gutters with their open ends joined to a shaft hollow at one end and placed above the surface of the water at the height to which the water was to be elevated. The gutters thus arranged radially extended to a short distance below the surface of the water which they scooped up successively when the shaft was rotated. Each gutter as it passed above the horizontal position delivered its water to the shaft to be subsequently discharged through a trough at the desired point. This primitive device continued in use from the remote ages of antiquity up to the 18th century without any change of construction, when La Faye, a member of the Royal Academy of Sciences of France, improved it by substituting a series of curved canals for the original straight gutters, thus developing the progenitor of the "scoop wheel," which, propelled by streams, are extensively used for draining purposes. La Faye's improvement and the geometrical reasoning which developed it are exhaustively described by Belidor (Tom. ii, 385, 387). While the tympanum consisted of a series of revolving gutters, the noria may be described as a number of "sweeps" arranged around a central shaft like the spokes of a wheel, each carrying on its outer end a vessel which fills as the rotary motion of the shaft plunges it beneath the surface of the water, and subsequently discharges its liquid freight into a reservoir placed at the upper part of the circle. It is commonly known as the Persian wheel. The "chain of buckets or pots" was an elaboration of the simple bucket and cord arrangement, by the introduction of a pulley operating an endless rope or chain, to which several buckets or pots were attached. It was employed by all the foremost nations of antiquity, and is yet used in many parts of Europe and Asia. Among half-civilized nations it was the highest type of hydraulic machines. Sometimes, when the source of supply was a river, as in the case of the Persian wheels on the Orontes, the driving wheels of the arrangement were placed in the river and propelled by its current. About the middle of the 17th century, European mechanics recognized that when the water was admitted into the receiving vessels of a noria or a chain of pots at the upper part of the circumference, it was converted into an overshot wheel, thus affording a means of power transmission to other machines, and in cases where the water supply was limited, but descended from a considerable elevation, it was substituted for the overshot wheel as a prime mover in operating mining pumps, dredging, threshing and other machines of a similar character; while as a conveyor, originally used exclusively as a water elevator, it has also been employed to raise mortar in the construction of buildings, city walls and fortifications, and for carrying grain and flour to the different floors of a mill. In its original form, that of the "sakia" of Egypt, it was unquestionably the pump introduced into Greece by Danaus when he dug the wells of Argos, 1485 B.C., about a PUMPS AND PUMPING MACHINERY thousand years before the building of Babylon by the Persians. Danaus was a brother of the Pharaoh Rameses, who resigned during the period the Israelites were in Egypt. He was compelled to leave that country on account of domestic troubles, and accompanied by his family and friends sailed for Greece. They landed on the coast of Peloponessus, and settled at Argos. According to Pliny (vii, 56), previous to the arrival of these Egyptians, the Greeks were unacquainted with wells and pumps; therefore, it is natural to conclude that the wells of Argos dug by Danaus were equipped with the Egyptian pumping devices most adaptable to wells, which was the chain of pots, and not a form of atmospheric or force pump, the pioneer of which is described in Hero's Spiritalia' as invented by Ctesibius of Alexandria, one of the most eminent mathematicians and mechanicians of that period, in the year 224 B.C. The most modern refinement of the chain of pots is the "chain pump," while Vera's "rope pump" and the hydraulic belt are applications of the same idea, and consist of endless double bands of rope or woolen cloth passing over two rollers, one placed below the surface of the water, the other at the point of delivery. The rollers are driven at a velocity ranging from one to two thousand feet per minute, and as the bands pass over the upper roller, the water held between them by capillarity is forced out by the pressure and discharged into a receiving chamber connected with the delivery spout. Water-raising machines embodying the principles of the screw, stated by some authorities as invented by Archimedes, the Greek geometrician and greatest mathematician of antiquity, and by others credited to the genius of Canon of Samos, a contemporary of Archimedes, about the year 242 B.C., are described by Vitruvius as of Egyptian origin, and were, according to other authentic records, employed in Egypt, for draining and irrigating land, many centuries before Archimedes visited that country. It consists of one or more flexible tubes of lead or leather, wound spirally around a solid cylinder of wood or iron, the ends of which are pivoted to supports, so that the whole arrangement may be revolved upon its axis, which is generally placed at an angle of 45 degrees to the horizontal. The lower end of the tube is placed below the surface of the water, and the upper end over a receiving trough at the desired elevation. When the machine is rotated the water entering the, lowest bend of the spiral is forced upward by each succeeding revolution into the other bends, and finally discharged out of the uppermost into the trough. The Roman screws were made with plank grooves arranged spirally around a solid cylinder, and the grooved cylinder thus structed was fitted into and revolved within a hollow cylinder of the same length. Thus foreshadowing the turbine pump of the present day. con The connecting link between the various more or less elementary forms of water elevators or "lifts already described, and the group of hydraulic machines designated as "displacement pumps," is the modern chain pump, consisting of a tube through which the water is raised by a series of pallets or pistons. The pump of Ctesibius appears to have been of this 18 character, although it consisted of only two single-acting pistons working in a cylinder, the water being raised by the up-stroke and expelled by the down-stroke, into a common receiving chamber. In this machine the atmospheric pressure was not taken into consideration, and its capabilities as a water-lifter remained unrecognized until 1643, when Torricelli, the great Italian physicist, announced that water could be raised in a tube by the pressure of air. In 1641, Galileo, when consulted by a Florentine pump-maker, had failed to demonstrate why water failed to rise in a closed tube above a height of 33 feet under the action of a suction pump. A year or two later, after the death of Galileo, Torricelli undertook the explanation of that fact, his experiments finally resulting in establishing the law that the heights attained by liquids in a closed tube, the upper end of which was a vacuum, under the pressure of the atmosphere, was proportional to their specific gravities. For example, under these conditions, the height of a column of mercury would be about 28 inches, while that of a column of water would be about 33 feet at the level of the sea. The direct result of this experiment was the invention of the siphon barometer, in which the empty space above the column of mercury is known as the Torricellian vacuum; but the further experiments of Pascal, a French mathematician and divine, in 1646, followed by those of Otto Guericke, a philosopher and mathematician of Magdeburg, Prussia, and of Candido del Buono, a member of the Academie del Cimento of Florence, led to the invention of the "air pump," an apparatus which is described under that title, and which must not be confounded with the atmospheric or displacement pump used for pumping water, which was not unknown to the ancients, and was probably used in some of its innumerable forms, long before the days of Ctesibius. The expansive energy of compressed air, hot air and steam, was probably employed by the ancients as the motive power of pressure engines to raise water many centuries before the Christian era. There are extant numerous authentic descriptions of devices equipped with piston bellows, employed for this purpose by the ancient Egyptians, Hindus, Chinese, Peruvians and the Aztecs. Also descriptions of hotair devices and pressure machines operated by steam, the majority of which were contrived by the members of the ancient priesthoods. A great many of these machines are described in the 'Spiritalia,' written by Heron, or Hero of Alexandria, a celebrated Egyptian mathematician and physicist, who lived in the 1st century A.D. The water-jet apparatus known as Hero's Fountain, although asserted to have been invented by him, was probably an old device at the time he described it. In either case, it is the oldest pressure engine ever described accurately in which a volume of air was used instead of a piston. In 1560 Baptista Porta, an Italian, published a work entitled 'Natural Magic, in which he described a method of producing a vacuum by the condensation of steam, and its application to devices for raising water. Similar descriptions are given in the writings of Jerome Cardan, also an Italian, published some time between 1515 and 1570. Therefore, although nothing new was discovered by De caus, whose writings were published in Frankfort in 1615 and in Paris in 1624, or by Fludd, Worcester, Savery and Papin, whose investigations and writings extended over the period from 1663 to 1698, the suggestions afforded by their experiments (subsequently elaborated by Freiburg in 1797 and Shone, Callon, Frizell and Pohlé in the period extending from 1870 to 1900) have led to the development of the various forms of modern air-lift pumps operated by compressed air and pulsometers operated by steam. Although pressure engines operated by air compressed under a head of water, as suggested by Papin in 1695, had been employed successfully to drain mines as early as 1755, when Hoel employed one in the mines of Chemnitz, Hungary, the application of steam for that purpose did not become an accomplisheed fact until a much later period. It is, however, interesting to note that the idea was suggested by Lord Bacon prior to 1679, in connection with the English mines, and probably was practically applied to a limited extent about that time. The history of the modern pumping engine, however, more properly begins with the construction of the Cornish engine. Up to the close of the 18th century, the only practical use of steam engines was in connection with pumping devices, and many notable steam pumping engines had been erected and successfully operated in the mines of Cornwall, England. The various improvements made in this engine from 1800 to 1840 finally culminated in the evolution of one_superior type which is now known as the "Cornish.» This engine gave highly satisfactory service for the particular purpose for which it was designed the raising of water out of deep mines where the constantly increasing depth of the shafts necessitated the adaptation of the same engine to the consequent increasing and changing loads. It is constructed upon the principle that the steam within the steam cylinder is used to lift a weighted pump plunger which after being raised upward to the limit of its stroke, descends slowly by its own weight and forces upward a column of water equal to that weight. The economy produced by the expansion of the steam in the steam cylinder when the steam is cut off during the descent of the plunger is due to the fact that the pressure and power of the steam first admitted is greatly in excess of what is necessary to lift the weighted plunger. This excess of power is taken up by the weights of the plunger at the beginning of its stroke and given out at the end when the power of the exhausted steam in the cylinder has fallen below the amount necessary to move the plunger, unless assisted by the power previously stored in it. The length of the stroke of the piston and of the plunger being determined solely by the operation of its steam, equilibrium and exhaust valves, it is absolutely necessary to maintain the steam pressure at a uniform rate, while the water raised must be received under a uniform head. In mine pumps the steam cylinder is placed at the top of the shaft, and the pump at the bottom, near the surface of the water. The steam piston is connected to the pump plunger by a beam made of heavy timbers, the weight of which, together with that of the weight of the plunger, forms the weight which, after being lifted by the steam cylinder, raises an equal weight of water when the plunger descends. In order to preserve the proper relation between the weight of the pump rods and plunger, and that of the water columns, and also keep the engine and pump at the proper speed, by maintaining the proper difference in the weight of the pump rods so as to overcome the friction of their guides, and that of the water in the delivery pipes, a large box, called the "balance bob," in which the adjusting weights in the shape of stones or pieces of iron are placed, is attached to the upper end of the pump rods. When the shafts become deeper and require the lengthening of the pump rods, the additional weight of the new timbers is counterbalanced by a readjustment of the weights in the "balance bob," thus adapting the engine to the new conditions. In its particular field of application, requiring only a slow action with no demand for continuous flow, it is safe to state that it has never been excelled by any other engine; but, its inordinate size, its action which requires the constant watchfulness of the engineer, its great first cost and expensive repairs, makes it unfit for waterworks, where the water has to be discharged through a long main to a great height above the pump, with a continuous and uniform delivery. The shortcomings of the Cornish engine, named above, led finally to its complete abandonment for waterworks, and called for a pumping engine that would fulfill the new requirements. This demand was met by the development of the "rotative" engine which, by employing revolving instead of reciprocating pistons, gave a positive motion. The steam power in the cylinder is applied to the pump piston in various ways through the medium of long or short beams, bell cranks or gearing, and in some instances directly through the pistons themselves; in all cases, however, the limit of the stroke of the steam piston and of the pump plunger being governed by a crank on a revolving shaft. Attached to this shaft is a fly-wheel which is designed to assist the crank to pass the centre at each end of its stroke and also to give up at the beginning of each stroke of the steam piston the excess of power imparted to it beyond that required to move the column of water. The function of the fly-wheel of a rotative engine is exactly similar to that of of the devices being applied to their respective the weighted plunger in a Cornish engine; both classes of engines to obtain the best economy in the consumption of steam, the early cut-off resulting in a high grade of expansion, much higher than it was possible to obtain by any other means at the time. They vary greatly in design and in the details of construction, and are made in sizes ranging from those used for supplying water to small towns, up to some of the largest and most expensive machines in the world, and operate either vertically or horizontally. They produce great economy in the use of steam at the expense of intricate machinery, but require expensive and massive foundations to absorb the shocks produced by their operation, while the momentum of the flywheel greatly increases the percentage of possible accidents. To follow further the progress of pumpingengine construction up to the invention and development of the "direct-acting steam pumps," which now represent the highest type of pump PUN-PUNCH ing machinery, it is necessary to take up the historical thread in the United States. Although steam pumping engines of the directacting type, beginning with the device invented by Thomas Newcomen and John Cawley, of Dartmouth, England (which was subsequently improved by Watt, who developed it into an engine of the double-acting type), were in great use for many years; the greatest improvement in this class of pumping engines was made by Henry R. Worthington of New York in 1840. His invention was the outcome of a long series of experiments on the application of steam to the propulsion of canal boats. It was a single direct-acting steam pump and was employed to feed the boilers of his propelling engine, and was patented for the first time in 1841. Although steam pumps of this type came immediately into extensive use for feeding boilers and for supplying moderate quantities of water under medium pressure, the intermittent action of their pump pistons and consequent irregular flow of water prevented them from being used in waterworks and for other purposes where large quantities of water had to be forced through long lines of pipes. To overcome this serious defect the same inventor produced the improved pump which is now generally known by his name. Bibliography. Butler, E., Modern Pumping and Hydraulic Machinery' (London 1913); Davey, H., Principles, Construction and Application of Pumping Machinery) (London 1905); Greene, A. M., Pumping Machinery' (New York 1911); Hague, C. A., Pumping Engines for Waterworks (New York 1907); Kelley, H. H., Pumps: Including the Air-Lift Pump (Atlanta, Ga., 1915); Nickel, F. F., 'Direct-Acting Steam Pumps' (New York 1915). Revised by RICHARD FERRIS. PUN, a play upon words alike or similar as to sound, but different as to sense. The pun has been familiar to all literatures, and in ancient times was used even in serious context. This was true also in England of the 17th and 18th centuries. Puns are met with in the tragedies of Shakespeare; in the works of the quaint Fuller; in the discourses of Bishop Andrews. The divines of colonial America did not lack for them. Mathey Byles won his reputation for wit chiefly through the appositeness and felicity of his puns. Thus, being a sturdy loyalist, he was for a time kept under surveillance by a sentinel whom he called his "observe-a-Tory." A parishioner called upon him and Byles, noting his ulcerated jaw, sent him to Copley, the artist, to have his tooth drawn. Among famous English punsters may be cited Sydney Smith, Lamb, Theodore Hook, Wilberforce and, above all, "Tom" Hood, most inveterate and happy of the coterie, who even remarked of a certain undertaker that he appeared anxious to "win a lively Hood." The pun has frequently been derided as an unworthy form of wit. John Donne is reported to have said that "He who would make a pun would pick a pocket"; and Holmes, in the Autocrat,' after denouncing verbicide, gives a pyrotechnic display of excellent puns. It is true, however, that the pun has found advocates in divines, philosophers, statesmen and literati. Many puns convey a weight of meaning which could hardly be secured by sentences of paraphrase. 15 PUNCH, a well-known English comic weekly, the most famous journal of the kind. The success of Philipon's Paris Charivari induced a staff of several Englishmen - some, as Douglas, Jerrold, Thackeray and John Leech, since famous to organize for the publication of a London Charivari, of which whole pages of text had been set up, when the scheme collapsed. This undertaking had, however, some indirect influence on the subsequent Punch. The idea of Punch appears to have been due originally to Ebenezer Landells, a Northumbrian wood engraver and draughtsman, and to have been developed by Henry Mayhew, a brilliant humorist of the time. "Mr. Punch" was the traditional jester of the puppet-show transformed into "the laughing philosopher and man of letters; the essence of all wit, the concentration of all wisdom." As finally agreed, Mayhew, Mark Lemon and Stirling Coyne were to be coeditors, Landells was to find drawings and engraving, and Douglas Jerrold and Gilbert à Beckett were to be among the outside contributors. The first number appeared on 17 July 1841. In two days two editions, each of 5,000 copies, were sold out. After some early vicissitudes, Punch became an English institution. A list of its writers and artists includes many famous names besides the jovial Lemon and the caustic Jerrold; Thackeray, "Tom" Hood, Charles Lever, "Tom" Taylor, Cuthbert Bede, Horace Smith, Shirley Brooks, F. C. Burnand, Artemas Ward, G. A. Sala, H. W. Lucy, John Leech, H. K. Browne ("Phiz”), Sir John Tenniel, George Du Maurier, Stacy Marks, Sir John Millais, Linley Sambourne and others. The editors have been Mark Lemon, 1841-70; Shirley Brooks 1870-74; "Tom" Taylor, 1874-80; Sir F. C. Burnand, 1880-1906; and Owen Seaman, 1906. Punch has done much to laugh out of court various shams, fads, affectations and forms of ostentation. In British politics it has remained wholly free from party bias. The present application of the word "cartoon" originated with Punch, the occasion being the first great exhibition of cartoons for the Houses of Parliament (July 1843), when Mr. Punch appeared with a rival series of sarcastic designs. Consult Spielmann, The History of "Punch" (1895); 'An Evening with Punch) (1895), selections from the first 50 years; à Beckett, A. W., 'The à Becketts of Punch' (1903). PUNCH, a beverage, commonly composed of wine or spirits, water, lemon juice and sugar, with occasionally an addition of some spice, as nutmeg or cinnamon. These are usually mixed in any desired proportions in a large bowl made for the purpose hence called the punchbowl. The beverage may be compounded as follows: Squeeze the juice out of three or four lemons, adding thereto the peel of one lemon cut in slices, 12 ounces of lump sugar and three and a half pints of boiling water; infuse this mixture for half an hour, then pour into the punch bowl, and add of rum and brandy rather less than a pint of each. Varieties of punch are called after one of their principal ingredients, gin, milk, orange, raspberry, tea, wine, etc. Punch was introduced into Great Britain from India, and it appears to be so called from the |