TRANSPORT MACHINES FOR LIQUIDS.
As regards their behavior under transportation, there is a similarity between liquids proper—for example, water—and such semi-solids as mor tar, and even between them and granular or pulverulent substances, such as sand and'flour. The methods employed to lift all these from a lower to a higher level and to carry them from place to place are in some instances practically the same. (See p. 32o.) For example, the simple method of filling a bucket with sand or mortar and of carrying it with its contents to the place where the material is needed finds its exact parallel when a pail is used to take water from a stream and to carry it away. The simplest means employed to raise a bucket or a bucket-like vessel and to carry such substances is the hand.
Slim-Mgt—A development of this is the shadoof (AZ. 112, fig. 1), which is the most ancient water-elevating device. It is found depicted in Egypt ian monuments as early as 1432 R. C. Figure 2 is a modern shadoof; the vessel being fastened by a cord to one end of a pole or beam hung upon a horizontal pivot, and the weight being so arranged that it requires a slight exertion to depress the vessel to the level of the water, the weight drawing up both the vessel and its contents to a position where the water may be poured out. A sapling with a thick, heavy butt as a counterpoise for the filled bucket was formerly largely used in rural districts of the United States, and was known as a " sweep;" this being a corruption of the old word " swape." The Picolah (pl. 112, fig. 9) somewhat resembles the shadoof, but it will draw a larger amount of water, the depression being effected by the weight of the operator, who walks along the beam until the vessel is sub merged and then goes back to the other end. The picotah is of course intermittent in its action.
most countries where the inhabitants have recourse to wells for water the swape in some form is employed. A somewhat complicated swape is that shown in Figure 6, which dates from A. D. 1568. There are two buckets, one at each end; the vibration of the beam
is effected by continuous rotary movement of a cam framed up of wood and turned by a paddle-wheel submerged in the stream in which the buckets dip. Two long rollers fixed to the under side of the beam, against which the working edge of the cam acts, lessen the friction.
number of vessels being fastened to the rim of a large wheel submerged in a spring or stream, rotation of the wheel will cause the vessels to be filled and then raised to a position where their contents will discharge into a suitable trough, which will convey the water to a lower level and to a distance. This arrangement, which is exhibited in Figure 3, is called a noria.
greater depths than would be convenient to reach with a noria the bucket-wheel 7) produces the same result, the vessels being fastened to a chain which passes from a wheel above and is submerged in the water below. The buckets discharge their contents at the highest point into a trough.
The Chain of Pots (fig. 1o) is another arrangement of the same princi ple, differing practically only in that the shaft carrying the bucket-wheel is driven by power applied to another wheel upon the same shaft.
The Bascule 5) is a double-ended swape discharging first from one end and then from the other into a trough at its pivot.
all the foregoing arrangements the water or other liquid raised is contained in buckets or bucket-like vessels, each complete in itself and independent of the others. These devices, however, may be arranged in a series comparable to the bucket-conveyer used in flour mills to carry grain, middlings, flour, etc. But in Figure II we find that the bucket proper is wanting, and that the water is drawn up by being forced along before slats or strips attached to a chain or rope passing through an open trough in which the slats fit approximately. This type of machine for raising liquids is analogous to the slat-conveyer used in carry ing grain, mortar, coal, etc.