### HYDROSTATIC TABLES

#### 2 Inches diameter

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 37.70 | 19.89 | 21.85 | | 2 | 75.40 | 39.79 | 43.69 | | 3 | 113.10 | 59.68 | 65.54 | | 4 | 150.80 | 79.58 | 87.39 | | 5 | 188.50 | 99.47 | 109.24 | | 6 | 226.19 | 119.37 | 131.08 | | 7 | 263.89 | 139.26 | 152.93 | | 8 | 301.59 | 159.16 | 174.78 | | 9 | 339.29 | 179.06 | 196.63 | | 10 | 376.99 | 198.95 | 218.47 | | 20 | 753.98 | 397.90 | 436.95 | | 30 | 1130.97 | 596.85 | 665.42 | | 40 | 1507.97 | 795.80 | 873.90 | | 50 | 1884.96 | 994.75 | 1092.37 | | 60 | 2261.95 | 1193.70 | 1310.85 | | 70 | 2638.94 | 1392.65 | 1529.32 | | 80 | 3015.93 | 1591.60 | 1747.80 | | 90 | 3392.92 | 1790.56 | 1966.27 | | 100 | 3769.91 | 1989.51 | 2184.75 | | 200 | 7539.82 | 3979.00 | 4369.50 |

#### 3 Inches diameter

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 84.8 | 44.76 | 49.16 | | 2 | 169.6 | 89.53 | 98.31 | | 3 | 254.5 | 134.29 | 147.47 | | 4 | 239.3 | 179.06 | 196.63 | | 5 | 424.1 | 223.82 | 245.78 | | 6 | 508.9 | 268.58 | 294.94 | | 7 | 533.7 | 313.35 | 344.10 | | 8 | 698.6 | 358.11 | 393.25 | | 9 | 703.4 | 402.87 | 442.41 | | 10 | 848.2 | 447.64 | 491.57 | | 20 | 1696.5 | 895.28 | 983.14 | | 30 | 2244.7 | 1342.92 | 1474.70 | | 40 | 3392.9 | 1790.56 | 1966.27 | | 50 | 4241.1 | 2238.19 | 2457.84 | | 60 | 5089.4 | 2685.83 | 2949.41 | | 70 | 5937.6 | 3133.47 | 3440.98 | | 80 | 6785.8 | 3581.11 | 3932.55 | | 90 | 7634.1 | 4028.75 | 4424.12 | | 100 | 8482.3 | 4476.39 | 4915.68 | | 200 | 16964.6 | 8952.78 | 9831.36 |

#### 2½ Inches diameter

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 58.90 | 31.08 | 34.14 | | 2 | 117.81 | 62.17 | 68.27 | | 3 | 176.71 | 93.26 | 102.41 | | 4 | 235.62 | 124.34 | 136.55 | | 5 | 294.52 | 155.43 | 170.68 | | 6 | 353.43 | 186.52 | 204.82 | | 7 | 412.33 | 217.60 | 238.96 | | 8 | 471.24 | 248.69 | 273.09 | | 9 | 530.14 | 279.77 | 307.23 | | 10 | 589.05 | 310.86 | 341.37 | | 20 | 1178.10 | 621.72 | 682.73 | | 30 | 1767.15 | 932.58 | 1024.10 | | 40 | 2356.20 | 1243.44 | 1365.47 | | 50 | 2945.25 | 1554.30 | 1706.83 | | 60 | 3534.29 | 1865.16 | 2048.20 | | 70 | 4123.34 | 2176.02 | 2389.57 | | 80 | 4712.39 | 2486.88 | 2730.94 | | 90 | 5301.44 | 2797.74 | 3072.30 | | 100 | 5890.49 | 3108.60 | 3413.67 | | 200 | 11780.98 | 6217.20 | 4827.34 |

#### 3½ Inches diameter

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 115.4 | 60.9 | 66.9 | | 2 | 230.9 | 121.8 | 133.8 | | 3 | 346.4 | 182.8 | 200.7 | | 4 | 461.8 | 243.7 | 267.6 | | 5 | 577.3 | 304.6 | 334.5 | | 6 | 692.7 | 365.6 | 401.4 | | 7 | 808.2 | 426.5 | 468.4 | | 8 | 923.6 | 487.4 | 535.3 | | 9 | 1039.1 | 548.3 | 602.2 | | 10 | 1154.5 | 609.3 | 669.1 | | 20 | 2309.1 | 1218.6 | 1338.2 | | 30 | 3463.6 | 1827.9 | 2007.2 | | 40 | 4618.1 | 2437.1 | 2676.3 | | 50 | 5772.7 | 3046.4 | 3345.4 | | 60 | 6927.2 | 3655.7 | 4014.5 | | 70 | 8081.7 | 4265.0 | 4683.6 | | 80 | 9236.3 | 4874.3 | 5352.6 | | 90 | 10390.8 | 5483.6 | 6021.7 | | 100 | 11545.4 | 6092.0 | 6690.8 | | 200 | 23090.7 | 12185.7 | 13381.5 | ## HYDROSTATICS

### HYDROSTATIC TABLES

#### 4 Inches diameter.

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 150.8 | 79.6 | 87.4 | | 2 | 301.6 | 159.2 | 174.8 | | 3 | 452.4 | 238.7 | 261.2 | | 4 | 603.2 | 318.3 | 349.6 | | 5 | 754.0 | 397.9 | 436.9 | | 6 | 904.8 | 477.5 | 524.3 | | 7 | 1055.6 | 557.1 | 611.7 | | 8 | 1206.4 | 636.6 | 699.1 | | 9 | 1357.2 | 716.2 | 786.5 | | 10 | 1508.0 | 795.8 | 873.9 | | 20 | 3115.9 | 1591.6 | 1747.8 | | 30 | 4523.9 | 2387.4 | 2621.7 | | 40 | 6631.9 | 3183.2 | 3495.6 | | 50 | 7539.8 | 3997.0 | 4369.5 | | 60 | 9047.8 | 4774.8 | 5243.4 | | 70 | 10555.8 | 5570.6 | 6117.3 | | 80 | 12063.7 | 6366.4 | 6991.2 | | 90 | 13571.7 | 7162.2 | 7865.1 | | 100 | 15079.7 | 7958.0 | 8739.0 | | 200 | 30159.3 | 15916.0 | 17478.0 |

#### 5 Inches diameter.

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 235.6 | 124.3 | 136.5 | | 2 | 471.2 | 248.7 | 273.1 | | 3 | 706.8 | 373.0 | 409.6 | | 4 | 942.5 | 497.4 | 546.2 | | 5 | 1178.1 | 621.7 | 682.7 | | 6 | 1413.7 | 748.1 | 819.3 | | 7 | 1649.3 | 870.4 | 955.8 | | 8 | 1884.9 | 994.8 | 1092.4 | | 9 | 2120.6 | 1119.1 | 1228.9 | | 10 | 2356.2 | 1243.4 | 1365.5 | | 20 | 4712.4 | 2486.9 | 2730.9 | | 30 | 7068.6 | 3730.3 | 4096.4 | | 40 | 9424.8 | 4973.8 | 5461.9 | | 50 | 11780.0 | 6217.2 | 6827.3 | | 60 | 14137.2 | 7460.6 | 8192.6 | | 70 | 16493.4 | 8704.1 | 9558.3 | | 80 | 18849.6 | 9947.5 | 10923.7 | | 90 | 21205.8 | 11191.0 | 12289.2 | | 100 | 23562.0 | 12434.4 | 13654.7 | | 200 | 47124.0 | 24868.8 | 27309.3 |

#### 4½ Inches diameter.

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 190.8 | 100.7 | 110.6 | | 2 | 381.7 | 201.4 | 221.2 | | 3 | 572.6 | 302.2 | 331.8 | | 4 | 763.4 | 402.9 | 442.4 | | 5 | 954.3 | 503.6 | 453.0 | | 6 | 1145.1 | 604.3 | 663.6 | | 7 | 1337.9 | 705.0 | 774.2 | | 8 | 1526.8 | 805.7 | 884.8 | | 9 | 1717.7 | 906.5 | 995.4 | | 10 | 1908.5 | 1007.2 | 1106.0 | | 20 | 3817.0 | 2014.4 | 2212.1 | | 30 | 5725.6 | 3021.6 | 3381.8 | | 40 | 7634.1 | 4028.7 | 4424.1 | | 50 | 9542.6 | 5035.9 | 5530.1 | | 60 | 11451.1 | 6043.1 | 6636.2 | | 70 | 13359.6 | 7050.3 | 7742.2 | | 80 | 15268.2 | 8057.5 | 8848.2 | | 90 | 17176.7 | 9064.7 | 9954.3 | | 100 | 19085.2 | 10071.9 | 11060.3 | | 200 | 38170.4 | 20143.8 | 22120.6 |

#### 5½ Inches diameter.

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 285.1 | 150.5 | 164.3 | | 2 | 570.2 | 300.9 | 328.3 | | 3 | 855.3 | 451.4 | 492.8 | | 4 | 1140.4 | 601.8 | 657.1 | | 5 | 1425.5 | 752.3 | 821.3 | | 6 | 1710.6 | 902.7 | 985.6 | | 7 | 1995.7 | 1053.2 | 1149.9 | | 8 | 2280.8 | 1203.6 | 1314.2 | | 9 | 2565.9 | 1354.1 | 1478.4 | | 10 | 2851.0 | 1504.6 | 1642.7 | | 20 | 5702.0 | 3009.1 | 3185.4 | | 30 | 8553.0 | 4513.7 | 4928.1 | | 40 | 11404.0 | 6018.2 | 6570.8 | | 50 | 14255.0 | 7522.8 | 8213.5 | | 60 | 17106.0 | 9027.4 | 9856.2 | | 70 | 19957.0 | 10531.9 | 11498.9 | | 80 | 22808.0 | 12036.5 | 13141.6 | | 90 | 25659.0 | 13541.1 | 14784.3 | | 100 | 29510.0 | 15045.6 | 16426.9 | | 200 | 57020.0 | 30091.2 | 31853.9 |

No. 161. ### HYDROSTATIC TABLES

#### 6 Inches diameter.

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 339.3 | 179.0 | 196.6 | | 2 | 678.6 | 358.1 | 393.3 | | 3 | 1017.9 | 537.2 | 589.9 | | 4 | 1357.2 | 716.2 | 786.5 | | 5 | 1696.5 | 895.3 | 983.1 | | 6 | 2035.7 | 1074.3 | 1179.8 | | 7 | 2375.0 | 1253.4 | 1376.4 | | 8 | 2714.3 | 1432.4 | 1573.0 | | 9 | 3053.6 | 1611.5 | 1769.6 | | 10 | 3392.9 | 1790.6 | 1966.3 | | 20 | 6785.8 | 3581.1 | 3932.5 | | 30 | 10178.8 | 5371.7 | 5898.8 | | 40 | 13571.7 | 7162.2 | 7865.1 | | 50 | 16964.6 | 8952.8 | 9831.4 | | 60 | 20357.5 | 10743.3 | 11797.6 | | 70 | 23750.5 | 12533.9 | 13763.9 | | 80 | 27143.4 | 14324.4 | 15730.2 | | 90 | 30536.3 | 16115.0 | 17696.5 | | 100 | 33929.2 | 17905.6 | 19662.7 | | 200 | 67858.4 | 35811.2 | 39325.4 |

#### 6½ Inches diameter.

| Feet high | Solidity in cubic inches | Weight in troy ounces | In avoirdupois ounces | |-----------|--------------------------|-----------------------|----------------------| | 1 | 398.2 | 210.1 | 230.7 | | 2 | 797.4 | 420.3 | 461.4 | | 3 | 1195.6 | 630.4 | 692.1 | | 4 | 1593.8 | 840.6 | 922.8 | | 5 | 1991.9 | 1050.8 | 1153.6 | | 6 | 2390.1 | 1260.9 | 1384.3 | | 7 | 2788.3 | 1471.1 | 1615.0 | | 8 | 3186.5 | 1681.2 | 1845.7 | | 9 | 3584.7 | 1891.3 | 2076.4 | | 10 | 3982.9 | 2101.5 | 2307.1 | | 20 | 7965.8 | 4202.9 | 4614.3 | | 30 | 11948.8 | 6304.9 | 6921.4 | | 40 | 15931.7 | 8405.9 | 9228.6 | | 50 | 19914.6 | 10507.4 | 11535.7 | | 60 | 23897.6 | 12608.9 | 13842.9 | | 70 | 27880.5 | 14710.4 | 16150.0 | | 80 | 31863.4 | 16811.8 | 18457.2 | | 90 | 35846.3 | 18913.3 | 20764.3 | | 100 | 39829.3 | 21014.8 | 23071.5 | | 200 | 79658.6 | 42029.6 | 46143.0 |

---

Under the article **Steam-Engine**, the reader will find a particular account of that useful invention, with a correct description and plate of it in its improved state.

The multiplying machine has no dependence on the action of the atmosphere; but, by the weight of water only, and without pump-work of any kind, raises water sufficient to serve a gentleman's seat, with an overplus for fountains, fish-ponds, &c.

AB are two copper pans or buckets of unequal multiplying weight and size, suspended to chains, which alternately wind off and on the multiplying-wheel YZ; whereof the wheel Y is smaller in diameter, and Z larger, in proportion to the different lifts each is designed to perform.

When the buckets are empty, they are stopped level with the spring at X, whence they are both filled with water in the same time.

The greater of the two, A, being the heavier when full, preponderates and descends ten feet, perhaps from C to D; and the lesser, B, depending on the same axis, is thereby weighed up or raised from E to F, suppose 30 feet.

Here, by particular little contrivances, opening the valves placed at bottom of each of these buckets, they both discharge their water in the same time, through apertures proportionable to their capacities; the smaller into the cistern W, whence it is conveyed for service by the pipe T, and the larger at D, to run waste by the drain below at H. The bucket B being empty, is so adjusted as then to overweight; and descending steadily as it rose betwixt the guiding rods VV, brings or weighs up A to its former level at X, where both being again replenished from the spring, they thence proceed as before. And thus will they continue constantly moving (merely by their circumstantial difference of water-weight, and without any other assistance than that of sometimes giving the iron-work a little oil) so long as the materials shall last, or the spring supply water.

The steadiness of the motion is in part regulated by a worm turning a jack-fly, and a little simple wheelwork at LM; which communicating with the multiplying wheel axle at M, is thereby moved forward or backward as the buckets either rise or descend. But what principally keeps the whole movement steady, is the equilibrium preserved in the whole operation by a certain weight of lead, at the end of a lever of fit length, and fixed on one of the spindles of the wheelwork, the numbers whereof are so calculated as, during the whole performance up and down, to let it move no more than one-fourth of a circle, from G to K; by which contrivance, as more or less of the chains suspending the buckets come to be wound off their respective wheels Y and Z, this weight gradually falls in as a counterbalance, and so continues the motion equable and easy in all its parts.

The water wasted by this machine is not above the hundredth part of what a water-wheel will expend, to raise an equal quantity. But where a fall, proportionable to the intended rise of water, cannot be had, with a convenient fewer to carry off the waste water over and above, this device cannot be well put in practice.

Water may also be raised by means of a stream AB turning a wheel CDE, according to the order of the fan wheel. Hydraulic letters, with buckets \(a, a, a, a, \ldots\) hung upon the wheel by strong pins \(b, b, b, b, \ldots\) fixed in the side of the rim; but the wheel must be made as high as the water is intended to be raised above the level of that part of the stream in which the wheel is placed.

As the wheel turns, the buckets on the right hand go down into the water, and are thereby filled, and go up full on the left hand, until they come to the top at \(K\), where they strike against the end \(n\) of the fixed trough \(M\), and are thereby overflown, and empty the water into the trough; from which it may be conveyed in pipes to the place which it is designed for; and as each bucket gets over the trough, it falls into a perpendicular position again, and goes down empty, until it comes to the water at \(A\), where it is filled as before.

On each bucket is a spring \(r\), which, going over the top or crown of the bar \(m\) (fixed to the trough \(M\)), raises the bottom of the bucket above the level of its mouth, and so causes it to empty all its water into the trough.

Sometimes this wheel is made to raise water no higher than its axis; and then, instead of buckets hung upon it, its spokes, \(C, d, e, f, g, h\), are made of a bent form, and hollow within; these hollows opening into the holes \(C, D, E, F\), in the outside of the wheel, and also into those at \(O\) in the box \(N\) upon the axis. So that as the holes \(CD, \ldots\) dip into the water, it runs into them; and as the wheel turns, the water rises in the hollow spokes \(c, d, \ldots\) and runs out in a stream \(P\) from the holes at \(O\), and falls into the trough \(Q\), from whence it is conveyed by pipes.

And this is a very easy way of raising water, because the engine requires neither men nor horses to turn it.

Engines for extinguishing fire are either forcing or lifting pumps; and being made to raise water with great velocity, their execution in great measure depends upon the length of their levers, and the force wherewith they are wrought.

For example, \(AB\) is the common squirting fire-engine. \(DC\) is the frame of a lifting-pump, wrought by the levers \(E\) and \(F\) acting always together. During the stroke, the quantity of water raised by the piston \(N\) spouts with force through the pipe \(G\), made capable of any degree of elevation by means of the yielding leather-pipe \(H\), or by a ball and socket, capable of turning every way, screwed on the top of the pump. Between the strokes on this machine the stream is discontinued. The engine is supplied by water poured in with buckets above; the dirt and filth whereof are kept from choking the pump work by help of the strainer \(IK\).

A considerable improvement has since been made to these machines, in order to keep them discharging a continual stream. In doing whereof it is not to be understood that they really throw out more water than do the squirting ones of the same size and dimensions with themselves; but that the velocity of the water, and of course the friction of all the parts, being less violent, the stream is more even and manageable, and may be directed hither or thither with greater ease and certainty than if it came forth only by fits and starts. The machine, thus improved, is therefore generally better adapted to the purpose intended than the former, especially in the beginning of these calamitous accidents.

The stream is made continual from the spring of air confined in a strong metal vessel \(CC\), in the fire engine \(AB\), fixed between the two forcing-pumps \(D\) and \(E\), wrought with a common double lever \(FG\) moving on the centre \(H\). The pistons in \(D\) and \(E\) both suck and fig. 6 force alternately, and are here represented in their different actions; as are also the respective valves at \(IK\) and \(LM\).

The water to supply this engine, if there be no opportunity of putting the end of a sucking-pipe, occasionally to be screwed on, into a moat or canal, which would spare much hurry and labour in case of fire, is also poured into the vessel \(AB\); and being strained through the wire grate \(N\), is, by the pressure of the atmosphere, raised through the valves \(K\) and \(M\) into the barrels of \(D\) or \(E\), when either of their forcers ascend; whence again it will be powerfully pushed when they descend into the air-vessel \(CC\), through the valves \(I\) and \(L\) by turns: by the force whereof the common air between the water and the top of the air-vessel \(O\) will from time to time be forcibly crowded into its room, and much compressed; and the air being a body naturally endowed with a strong and lively spring, and always endeavouring to dilate itself every way alike in such a circumstance, bears strongly both against the sides of the vessel wherein it is confined, and the surface of the water thus injected; and so makes a constant regular stream to rise through the metal pipe \(P\) into the leather one \(Q\), screwed thereon; which being flexible, may be led about into rooms and entries, as the case may require.

Should the air contained in this vessel be compressed into half the space it took up in its natural state, the spring thereof will be much about doubled; and as before it equalled and was able to sustain the pressure of a single atmosphere, it having now a double force, by the power of that spring alone will throw water into air, of the common degree of density, about thirty feet high. And should this compression be still augmented, and the quantity of air which at first filled the whole vessel be reduced into one-third of that space, its spring will be then able to resist, and consequently to raise the weight of a treble atmosphere; in which case, it will throw up a jet of water sixty feet high. And should so much water again be forced into the vessel as to fill three parts of the capacity, it will be able to throw it up about ninety feet high; and wherever the service shall require a still greater rise of water, more water must be thrust into this vessel; and the air therein being thus driven by main force into a still narrower compass, at each explosion, the gradual restitution thereof to its first dimensions is what regularly carries on the stream between the strokes, and renders it continual during the operation of the machine.

This experiment, in little, may be either made on the lifting or forcing pump, the nobels of which may be left large, on purpose for the reception of the small pipe \(F\), reaching nearly to the valve at \(E\), and occasionally to be screwed in. Between this pipe and the sides and top of the nobel \(H\), a quantity of air will necessarily be lodged, which, when the force acts, will be compressed at every stroke by the rise of the water; more whereof will be pushed through \(E\) than can immediately get away, through the pipe \(F\), which Archimedes's screw is a sort of spiral pump, and receives its name from its inventor. It consists of a long cylinder AB with a hollow pipe CD round it; and is placed in an oblique position, with the lower end in the water, the other end being joined to the lower end of the winch IK, supported by the upright piece IR.

When this screw is immersed in the water, it immediately rises in the pipe by the orifice C to a level with the surface of the water EF; and if the point in the spiral, which in the beginning of the motion is coincident with the surface of the water, happen not to be on the lower side of the cylinder, the water, upon the motion of the screw, will move on in the spiral till it come to the point on the other side that is coincident with the water. When it arrives at that point, which we will suppose to be O, it cannot afterwards possess any other part of the spiral than that on the lowest part of the cylinder; for it cannot move from O toward H or G, because they are higher above the horizon; and as this will be constantly the case after the water in the spiral has attained the point O, it is plain it must always be on the under side of the cylinder.

But because the cylinder is in constant motion, every part of the spiral screw, from O to D, will by degrees succeed to the under part of the cylinder. The water therefore must succeed to every part of it, from O to D, as it comes on the lower side; that is, it must ascend on the lower part of the cylinder through all the length of the pipe, till it come to the orifice at D, where it must run out, having nothing further to support it.

There is a simple and easy method of working two pumps at once, by means of the balance AB, having a large iron ball at each end, and placed in equilibrium on the two spindles C, as represented in the 6th figure. On the right and left are two boards I, nailed to two cross pieces, fastened to the axis of the machine. On these boards the person who is to work the pump stands, and supports himself by a cross piece nailed to the two posts ED, fig. 5. At the distance of ten inches on each side the axis are fastened the pistons MN.

The man, by leaning alternately on his right and left foot, puts the balance in motion, by which the pumps OP are worked, and the water thrown into the pipe H, and carried to a height proportional to the diameter of the valves and the force of the balance. There must be placed on each side an iron spring, as F and G, to return the balance, and prevent its acquiring too great velocity.

The chain-pump, A B, is ordinarily made from twelve to twenty-four feet long; and consists of two collateral square barrels, and a chain of pistons of the same form, fixed at proper distances thereon. The chain is moved in these round a coarse kind of wheel-work at either end of the machine, the teeth whereof are so made as to receive one half of the flat pistons, and let them fold in; and they take hold of the links as they rise in one of the barrels, and return by the other. The machine is wrought either by the turning of one handle or two, according to the labour required, depending on the height to which the water is to be raised. A whole row of the pistons (which go free of the sides of the barrel by perhaps a quarter of an inch) are always lifting when the pump is at work; yet do they, by the general push in the ordinary way of working, as it is pretty brisk, commonly bring up a full bore of water in the pump. This machine is so contrived, that, by the continual folding in of the pistons, stones, dirt, and whatever happens to come in the way, may also be cleared; and therefore it is generally made use of to drain ponds, to empty sewers, and remove foul waters, in which no other pump could work.

The last machine to be described consists of five pieces of board, forming a sort of scoop, as B. The handle C is suspended by a rope fastened to three poles, placed in a triangle, and tied together at A.

The working of this machine consists entirely in balancing the scoop that contains the water, and directing it in such manner that the water may be thrown in any given direction. It is evident that the operation of this machine is so very easy, that it may rather be considered as an agreeable and salutary recreation than hard labour.

With this machine a man of moderate strength, by two strokes in four seconds, can draw half a cubic foot of water, that is, more than four hundred cubic feet in an hour.

This machine is frequently used by the Dutch in emptying the water from their dikes.

Sect. VI. Entertaining Experiments.

1. Several amusing appearances may be produced by disguising or diversifying a syphon. It may, for example, be disguised in a cup, from which no liquor Tantalus's will flow till the fluid is raised therein to a certain cup, &c., height; but when the efflux is once begun, it will continue till the vessel is emptied. Thus, fig. 11, is a plate cup, in the centre whereof is fixed a glass pipe A, continued through the bottom at B, over which is put another glass tube, made air-tight at top by means of the cork at C; but left so open at foot, by holes made at D, that the water may freely rise between the tubes as the cup is filled. Till the fluid in the cup shall have gained the top of the inmost pipe at A, no motion will appear. The air however from between the two pipes being in the mean time extruded, by the rise of the denser fluid, and passing down the inner tube, will get away at bottom; and the water, as soon as the top of the inclosed tube shall be covered thereby, will very soon follow, and continue to rise in this machine, as in the syphon, till the whole is run off.

This is called by some, a Tantalus's cup; and, to humour the thought, a hollow figure is sometimes put over the inner tube, of such a length, that when the fluid is got nearly up to the lips of the man, the syphon may begin to act and empty the cup.

This is in effect no other than if the two legs of the syphon were both within the vessel, as in fig. 12, into which the water poured will rise in the shorter leg of the machine, by its natural pressure upwards, to its own level; and when it shall have gained the bend of the syphon, it will come away by the longer leg, as already already described. An apple, an orange, or any other solid, may be put into the vessel, to raise the water, when it is near the bend, to let it run, by way of amusement.

Again, let the handle of the cup, fig. 11, be hollow; let the tube CD, screwed therein, communicate freely with the water poured into the cup, that it may rise equally in both. Being once above the level ED, it will overflow, and descending through the cavity DB, will empty the cup of its liquor.

2. The device called the fountain at command, acts upon the same principle with the syphon in the cup. Let two vessels A and B be joined together by the pipe C, which opens into them both. Let A be opened at top, B close both at top and bottom (save only a small hole at b to let the air get out of the vessel B), and A be of such a size as to hold about six times as much water as B. Let a syphon DEF be soldered to the vessel D, so that the part DEe may be within the vessel, and F without it; the end D almost touching the bottom of the vessel, and the end F below the level of D: the vessel B hanging to A, by the pipe C (soldered into both), and the whole supported by the pillars G and H upon the land I. The bore of the pipe must be considerably less than the bore of the syphon.

The whole being thus constructed, let the vessel A be filled with water, which will run through the pipe C, and fill the vessel B. When B is filled above the top of the syphon at E, the water will run through the syphon, and be discharged at F. But as the bore of the syphon is larger than the bore of the pipe, the syphon will run faster than the pipe, and will soon empty the vessel B; upon which the water will cease from running through the syphon at F, until the pipe C refills the vessel B, and then it will begin to run as before. And thus the syphon will continue to run and stop alternately, until all the water in the vessel A has run through the pipe C.—So that, after a few trials, one may easily guess about what time the syphon will stop, and when it will begin to run; and then, to amuse others, he may call out, "stop," or "run," accordingly.

3. This figure represents a very pretty portable fountain, which, being charged with water, and inverted, will play a jet nearly as high as the reservoir, till the fluid is exhausted; and then turned up on the other end, the same thing will happen, and a real clepsydra, or water-clock, be thereby formed.

This device consists of two hollow vessels, A and B, communicating with each other only by the recurved tubes C and D; at the ends of which, E and F, are placed small adjuagates to direct the jet. G and H are two open tubes, soldered into the bottom of the basins belonging to A and B, through which the water flows in, and fills those vessels to a certain height, that is, according to their length. They by their disposition also prevent the return of the water the same way, when the machine is turned upside down.

4. Provide a cylindric vessel of glass or china, ABCD, about a foot high, and four inches diameter. Make a hole in its bottom, in which glue a small glass-tube E, of about one-third of an inch diameter, and whose end has been partly closed in the flame of a lamp, so that it will not suffer the water to pass out but by drops, and that very slowly. Cover the top of the vessel with a circle of wood F, in the centre of which make a round hole about half an inch diameter.

Have a glass tube GH, a foot high, and a quarter of an inch diameter; and at one end let it have a small glass globe I, to which you may hang a weight L, by which it is kept in equilibrium, on or near the surface of the water; or you may pour a small quantity of mercury into the tube, for the same purpose. Fill the vessel with water; put the tube in it, and over it place the cover F, through the hole of which the tube must pass freely up and down. Now, as the water drops gradually out of the vessel, the tube will continue to descend till it come to the bottom.

Therefore, paste on the tube a graduated paper, and put it in the vessel when nearly full of water. Hang a watch by it, set to a certain hour; and as the tube descends, mark the hours, with the half and quarter hours. If the vessel be sufficiently large, with regard to the hole at the bottom, it will go for 12 hours, a day, or as much longer as you please, and requires no other trouble than that of pouring in water to a certain height. Care must be had, however, that the water be clean; for if there be any sediment, it will in time stop the small hole at bottom, or at least render the motion of the water irregular.

The vessel may be of tin, but the pipe at bottom should be glass, that its small aperture may not alter by use. It is to be observed, that the tube of one of these clocks is not to be graduated by another: for though the vessel be of the same diameter at top, it may not be perfectly cylindrical throughout; nor is it easy to make the hole at the bottom of one vessel exactly of the same dimension with that of another.

5. The Hon. Mr Charles Hamilton has described Clepsydra, a curious clepsydra or water-clock of new construction. An open canal ee, supplied with a constant and equal stream by the syphon d, has at each end ff, open pipes of exactly equal bores, which deliver the water that runs along the canal e, alternately into the vessels g 1, g 2, in such a quantity as to raise the water from the mouth of the tantalus t, exactly in an hour. The canal ee is equally poised by the two pipes f 1, f 2, upon a centre r, the ends of the canal e are raised alternately, as the cups z z are depressed, to which they are connected by lines running over the pulleys ll. The cups z z are fixed at each end of the balance mm, which moves up and down upon its centre v. n 1, n 2, Are the edges of two wheels or pulleys, moving different ways alternately, and fitted to the cylinder o by oblique teeth both in the cavity of the wheel and upon the cylinder, which, when the wheel n moves one way, that is, in the direction of the minute hand, meet the teeth of the cylinder and carry the cylinder with it, and, when n moves the contrary way, slip over those of the cylinder, the teeth not meeting, but receding from each other. One or other of these wheels n n continually moves o in the same direction, with an equable and uninterrupted motion. A fine chain goes twice round each wheel, having at one end a weight x, always out of water, which equi-ponderates with y at the other end, when kept floating on the surface of the water in the vessel g, which y must always be; the two cups z, z, one at each end of the balance, keep it in equilibrium, till one of them is forced down down by the weight and impulse of the water, which it receives from the tantalus \( t \): each of these cups \( z, z \), has likewise a tantalus of its own \( b, b \), which empties it after the water has done running from \( g \), and leaves the two cups again in equilibrium: \( q \) is a drain to carry off the water. The dial-plate, &c., needs no description. The motion of the clepsydra is effected thus: As the end of the canal \( e \), fixed to the pipe \( f \), is, in the figure, the lowest, all the water supplied by the typhon runs through the pipe \( f \), into the vessel \( g \), till it runs over the top of the tantalus \( t \); when it immediately runs out at \( i \) into the cup \( z \), at the end of the balance \( m \), and forces it down; the balance moving on its centre \( v \). When one side of \( m \) is brought down, the string which connects it to \( f \), running over the pulley \( l \), raises the end \( f \), of the canal \( e \), which turns upon its centre \( r \), higher than \( f \); consequently, all the water which runs through the syphon \( d \) passes through \( f \) into \( g \), till the same operation is performed in that vessel, and so on alternately. As the height the water rises in \( g \) in an hour, viz., from \( s \) to \( t \), is equal to the circumference of \( n \), the float \( y \) rising through that height along with the water, lets the weight \( x \) act upon the pulley \( n \), which carries with it the cylinder \( o \); and this, making a revolution, causes the index \( k \) to describe an hour on the dial plate. This revolution is performed by the pulley \( n \); the next is performed by \( n \), whilst \( n \) goes back, as the water in \( g \) runs out through the tantalus; for \( y \) must follow the water, as its weight increases, out of it. The axis \( o \) always keeps moving the same way; the index \( p \) describes the minutes; each tantalus must be wider than the syphon, that the vessels \( g \) may be emptied as low as \( s \), before the water returns to them.

6. To the tube wherein the water is to rise, fit a spherical or lenticular head, \( A B \), made of a plate of metal, and perforated at top with a great number of little holes. The water rising with vehemence towards \( A B \), will be there divided into innumerable little threads, and afterwards broke, and dispersed into the finest drops.

7. To the tube \( A B \), folder two spherical segments \( C \) and \( D \), almost touching each other; with a screw \( E \), to contract or amplify the interstice or chink at pleasure. Others choose to make a smooth, even cleft, in a spherical or lenticular head, fitted upon the tube. The water spouting through the chink, or cleft, will expand itself in manner of a cloth.

8. Make a hollow globe \( A \), of copper or lead, and of a size adapted to the quantity of water that comes from the pipe to which it is to be placed. Pierce a number of small holes thro' this globe, that all tend towards its centre; observing, however, that the diameters of all these holes, taken together, must not exceed that of the pipe at the part from whence the water flows. Annex to it a pipe \( B \), of such height as you think convenient; and let it be screwed at \( C \), to the pipe from whence the jet flows. The water that comes from the jet rushing with violence into the globe, will be forced out at the holes, with the direction in which they are made, and will produce a very pleasing sphere of water.

9. Procure a little figure made of cork, as \( A B \), which you may paint, or dress in a light stuff, after your own fancy. In this figure you are to place the small hollow cone \( C \), made of thin leaf-brafs. When the figure is placed on the jet-d'eau that plays in a perpendicular direction, it will remain suspended on the top of the water, and perform a great variety of motions.

If a hollow ball of copper, of an inch diameter, and very light, be placed on a similar jet, it will, in like manner, remain suspended, revolving on its centre, and spreading the water all round it, in the manner represented by fig. 6. or Plate CCXLIV. fig. 1.—But note, that as it is necessary the ball, &c. when on the descent, should keep the same precise perpendicular wherever it rote (since otherwise it would miss the stream and fall downright), such a fountain should only be played in a place free from wind.

10. Make a hollow leaden cone \( A \), whose axis is one-third of the diameter of its base. The circle \( C \), that forms its base, must be in proportion to the surface of the water that flows from the jet on which it is to be placed, that it may flow from it equally on all sides. To fig. 4. The cone join the pipe \( B \), which serves not only as a support, but is to be pierced with a number of holes, that it may supply the cone with a sufficient quantity of water. Screw the tube just mentioned to the top of that from whence the jet proceeds.—The water that rushes into the cone from the pipe, will run over its circumference, and form a hemispherical cascade. If this piece be so constructed that it may be placed in a reversed position, it will produce a fountain in the form of a vase, (see fig. 2.) and if there be a sufficient quantity of water, both these pieces may be placed on the same pipe, the fountain at top and the cascade underneath, which by their variety will produce a very pleasing appearance.

11. Let there be two portions of a hollow sphere, that are very shallow; and let them be so joined together, that the circular space between them may be very narrow. Fix them vertically to a pipe from whence a jet proceeds. In that part by which the portions of the sphere are joined, there must be made a number of holes; then the water rushing into the narrow cavity will be forced out from the holes, and produce a regular figure of the sun, as in the plate. This piece requires a large quantity and force of water to make it appear to advantage.

Several pieces of this sort may be placed over each other, in a horizontal direction, and so that the same pipe may supply them all with water (see fig. 6. of plate CCXLV.) It is proper to observe, that the diameter of these pieces must continually diminish, in proportion to their distance from the bottom.

12. Make a hollow circle \( A \), the sides of which are to be pierced with 12 or 15 holes, made in an inclined direction: or you may place the like number of small tubes round the circle. Fix this circle on the top of a jet, in such manner that it may turn freely round, fig. 8. The water rushing violently into the hollow circle will keep it in continual motion; and at the same time forcing out of the holes or small tubes, will form a revolving figure with rays in different directions, as in the plate.

13. Provide a strong copper vessel \( A \), of such figure as you think convenient; in which folder a pipe \( B E \), of the same metal. Let there be a cock at \( H \), which must be made so tight that no air can pass by it. The pipe \( B E \) must go very near the bottom of the vessel, but not touch it. There must be another pipe F, at whose extremity G there is a very small hole: this pipe must be screwed into the former.

The vessel being thus disposed, take a good syringe; and placing the end of it in the hole at G, open the cock, and force the air into the vessel; then turn the cock and take out the syringe. Repeat this operation several times, till the air in the vessel be strongly condensed. Then fill the syringe with water, and force it into the vessel, in the same manner as you did the air; and repeat this operation till you can force no more water into the vessel; then shut the cock. This vessel will be always ready to perform an extempore jet d'eau: for, on turning the cock, the spring of the compressed air will force out the water with great violence, and the jet will continue, though constantly decreasing in force, till the water is all exhausted, or the air within the vessel is come to the same density with that without.

14. Let there be made a tin vessel, about six inches high, and three inches in diameter. The mouth of this vessel must be only one quarter of an inch wide; and in its bottom make a great number of small holes about the size of a common sewing needle. Plunge this vessel in water, with its mouth open; and when it is full, cork it up and take it out of the water. So long as the vessel remains corked, no water whatever will come out; but as soon as it is uncorked, the water will issue out from the small holes at its bottom. You must observe, that if the holes at its bottom of the vessel be more than one sixth of an inch diameter, or if they be in too great number, the water will run out though the vessel be corked; for then the pressure of the air against the bottom of the vessel will not be sufficient to confine the water.

An experiment similar to this is made with a glass filled with water, over which a piece of paper is placed. The glass is then inverted; and the water, by the pressure of the air under it, will remain in the glass. That the paper, though the seeming, is not the real support of the water, will appear from no. 25.

15. In this fountain, the air being compressed by the concealed fall of water, makes a jet, which, after some continuance, is considered by the ignorant as a perpetual motion; because they imagine that the same water which fell from the jet arises again. The boxes CE and DYX being close, we see only the bason ABW, with a hole at W, into which the water spouting at B falls; but that water does not come up again; for it runs down through the pipe WX into the box DYX, from whence it drives out the air through the ascending pipe YZ, into the cavity of the box CE, where, pressing upon the water that is in it, it forces it out through the spouting pipe OB, as long as there is any water in CE; so that this whole play is only whilst the water contained in CE, having spouted out, falls down through the pipe WX into the cavity DYX. The force of the jet is proportionable to the height of the pipe WX, or of the boxes CE and DY above one another: the height of the water, measured from the bason ABW to the surface of the water in the lower box DYX, is always equal to the height measured from the top of the jet to the surface of the water in the middle cavity at CE. Now, since the surface CE is always falling, and the water in DY always rising, the height of the jet must continually decrease, till it is shorter by the height of the depth of the cavity CE, which is emptying, added to the depth of the cavity DY, which is always filling; and when the jet is fallen so low, it immediately ceases. The air is represented by the points in this figure. To prepare this fountain for playing, which should be done unobserved, pour in water at W, till the cavity DYX is filled; then invert the fountain, and the water will run from the cavity DYX into the cavity CE, which may be known to be full, when the water runs out at B held down. Set the fountain up again, and, in order to make it play, pour in about a pint of water into the bason ABW; and as soon as it has filled the pipe WX, it will begin to play, and continue as long as there is any water in CE. You may then pour back the water left in the bason ABW, into any vessel, and invert the fountain, which, being set upright again, will be made to play, by putting back the water poured out into ABW; and so on as often as you please.

The fountain fig. 3. is of the same kind; but having double the number of pipes and concealed cavities, it plays as high again. In order to understand its structure, see fig. 7. The bason is A, the four cavities are B, C, D, and E, from which the water through the pipe f G spouts up to double the height of the fountain, the air at E, which drives it, being doubly condensed. The water going down the pipe I (e.g., three feet long), condenses the air that goes up into the cavity C through the pipe z, so as to make it stronger than the common air; then the water, which falling in the pipe 3 from C to D, is capable, by the height of its fall, of condensing the air at E, so as to make it stronger, being pushed at C by air already condensed into left space, causes the air at E to be condensed twice as much; that is, to be stronger than common air; and therefore it will make the water at G spout out with twice the force, and rise twice as high as it would do if the fountain had been of the same structure with the former. In playing this fountain turn it upside down, and taking out the plugs g, h, fill the two cavities C and E, and having shut the holes again, set the fountain upright, and pour some water into the bason A, and the jet will play out at G; but the fountain will begin to play too soon, and therefore the best way is to have a cock in the pipe 3, which, being open, whilst the cavities C and E are filled, and shut again before the fountain is set up, will keep the water thrown into the bason from going down the pipe i, and that of the cavity C from going down the pipe 3, by which means the fountain will not play before its time, which will be as soon as the cock is opened.

16. Procure a tin vessel ABC, five inches high and four inches in diameter; and let it be closed at top. To the calcaire, bottom of this vessel let there be soldered the pipe DE, fig. 3, of ten inches length, and half an inch in diameter: this pipe must be open at each end, and the upper end must be above the water in the vessel. To the bottom also fix five or six small tubes F, about one-eighth of an inch diameter. By these pipes the water contained in the vessel is to run slowly out.

Place this machine on a sort of tin bason GH, in the middle of which is a hole of one quarter of an inch diameter. diameter. To this tube DE, fix some pieces that may support the vessel over the basin; and observe that the end D, of the tube DE, must be little more than one quarter of an inch from the basin. There must be also another vessel placed under the basin, to receive the water that runs from it.

Now, the small pipes discharging more water into the basin than can run out at the hole in its centre, the water will rise in the basin, above the lower end of the pipe DE, and prevent the air from getting into the vessel AB; and consequently the water will cease to flow from the small pipes. But the water continuing to flow from the basin, the air will have liberty again to enter the vessel AB, by the tube DE, and the water will again flow from the small pipes. Thus they will alternately stop and flow as long as any water remains in the vessel AB.

As you will easily know, by observing the rise of the water, when the pipes will cease to flow, and by the fall of it, when they will begin to run again, you may safely predict the change; or you may command them to run or stop, and they will seem to obey your orders.

17. This fountain begins to play when certain candles placed round it are lighted, and stops when those candles are extinguished. It is constructed as follows. Provide two cylindrical vessels, AB and CD. Connect them by tubes open at both ends, as HL, FB, &c., so that the air may descend out of the higher into the lower vessel. To these tubes fix candlesticks H, &c., and to the hollow cover CF, of the lower vessel, fit a small tube EF, furnished with a cock G, and reaching almost to the bottom of the vessel. In G let there be an aperture with a screw, whereby water may be poured into CD.

Now, the candles at H, &c., being lighted, the air in the contiguous pipes will be thereby rarified, and the jet from the small tube EF will begin to play: as the air becomes more rarified, the force of the jet will increase, and it will continue to play till the water in the lower vessel is exhausted. It is evident, that as the motion of the jet is caused by the heat of the candles, if they be extinguished, the fountain must presently stop.

18. This fountain is contrived to play by the spring of the air, increased by the heat of the sun, and serves also for a dial at the same time. GNS is a hollow globe of thin copper, eighteen inches in diameter, supported by a small inverted basin, resting on a frame ABC, with four legs, between which there is a large basin of two feet diameter. In the leg C there is a concealed pipe, proceeding from G, the bottom of the inside of the globe, along HV, and joining an upright pipe u I, for making a jet at I. The short pipe Tu, going to the bottom of the basin, has a valve at u under the horizontal part HV, and another valve at V above it, and under the cock, &c. At the north pole N, there is a screw for opening a hole, through which the globe is supplied with water. When the globe is half filled, let the machine be set in a garden, and as the sun heats the copper and rarifies the included air, the air will press upon the water, which, descending through the pipe GCHV, will lift up the valve V, and shut the valve u, and the cock being open, spout out at I, and continue to do so for a long time if the sun shines, and the adjustment be small. At night, as the air condenses again by the cold, the outward air pressing into the adjustment I, will shut the valve V, but by its pressure on the basin DuH, push up the water which has been played in the daytime through the valve u, and the pipe uHG into the globe, so as to fill it up again to the same height which it had at first, and the next sun-shine will cause the fountain to play again, &c. The use of the cock is to keep the fountain from playing till you think proper: a small jet will play five or eight hours.

If the globe be set to the latitude of the place, and rectified before it be fixed, with the hour-lines or meridians drawn upon it, the hours marked, and the countries painted, as on the common globe, it will form a good dial: the sun then shining upon the same places in this globe as it does on the earth itself. This fountain was invented by Dr Defaguliers.

19. There is a pretty contrivance, by which the specific gravity of the body is so altered, that it rises and sinks in water at our pleasure. Let little images of men, about an inch high, of coloured glass, be bespoke at a glass-house; and let them be made so as to be hollow within, but so as to have a small opening into this hollow, either at the sole of the foot or elsewhere. Let them be set afloat in a clear glass phial of water, filled within about an inch of the mouth of the bottle; then let the bottle have its mouth closed with a bladder, closely tied round its neck, so as to let no air escape one way or the other. The images themselves are nearly of the same specific gravity with water, or rather a little more light, and consequently float near the surface. Now when we press down the bladder, tied on at the top, into the mouth of the bottle, and thus press the air upon the surface of the water in the bottle; the water being pressed will force into the hollow of the image through the little opening; thus the air within the images will be pressed more closely together, and being also more filled with water now than before, the images will become more heavy, and will consequently descend to the bottom; but, upon taking off the pressure from above, the air within them will again drive out the water, and they will rise to the same heights as before. If the cavities in some of the images be greater than those in others, they will rise and fall differently, which makes the experiment more amusing.