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WEIGHT OF CAST-IRON PIPES IN POUNDS PER LINEAL FOOT.

THICKNESS IN INCHES.

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30.83 41.71 8 21.69 32.9 44.4 22.71 34.52 46.64 59.07 71.8 9 23.93 36.36 49.09 62.13 25.16 38.2 51.54 10 26.38 40.04 54

52.92 64.42

76.23

88.35 100.8 113.5

56.21 68.33

80.76

93.49 106.5

119.9

84.84 98.18 111.8

125.8

II

75.47 65.2 79.16 68.26 82.84 71.33 86.52

89.13 103.1 117.4 131.9

93.42 108

122.9

138.1

[blocks in formation]

27.62 41.88 56.46 II 28.84 43.71 58.9 74.39 90.19 106.3 122.7

12

30.06 45.55 61.35 77.46 93.6 110.6

139.4 156.4 127.6 145 162.6

NOTE. For each Joint add one foot in length of the Pipe.

Heavy iron-work is generally taken at a rate based on tons weight. This is the gross weight including packages. Where iron-work is hollow, such as in boilers, pipes, barrels, cylinders, and wheels, or where the machinery is light, as in large cases, the freight is assessed on tons of forty cubic feet. This is on the gross measurement outside to outside of all projections.

A boiler with a dome or chimney will be measured from the top of either. A globe 3' 6" diameter would be meas

ured as 41.12 cubic feet, and would pay freight as over one ton though it weighed but a hundredweight. If made of iron solid it would weigh four and a half tons and pay upon weight.

Pipes are objects which are frequent causes of misunderstanding, as the weight and cubic contents approach in some sizes closely, especially when packed as they should be, so that their projections or flanges miss each other.

Shippers will, however, measure them as square blocks the extreme size of the flanges, unless this is arranged. Their weight may be found on preceding page.

WEIGHT OF A SUPERFICIAL FOOT IN POUNDS, AND NUMBER OF SUPERFICIAL FEET PER TON OF IRON AND STEEL PLATING OF VARIOUS THICKNESSES.

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The following weights will aid calculations.
Weight of Iron.

5% inch diameter = 1 lb. per lineal foot run.
% inch diameter = 2 lbs. per lineal foot.
14 inch diameter = 4 lbs. per lineal foot.
134 inch diameter = 8 lbs. per lineal foot.
I inch square

I inch thick x I foot square

I inch cube wrought iron

1 inch cube cast iron

= 3.33 lbs. per lineal foot, or 10 lbs.per lineal yard.

[blocks in formation]

400 cubic inches of wrought iron = 1 cwt., or 112 lbs.

400 cubic inches of cast iron

I cwt., or 112 lbs.

CHAPTER III.

AVAILABLE POWERS.

Natural Forces. If the natural elements of light, wind, waterflow, and muscular force could be always relied upon to perform their functions with certainty and regularity, there would be little cause to consider the comparative advantages of adopting any other means of obtaining force.

Although these natural forces are lacking in those important features, there are very often local advantages which modify or outweigh the lack of regular supply, and which should be inquired into before deciding against their

use.

These may be classified as follows:

I. In muscular manual force, the cheapness in certain localities of labour, as in the East, whereby it may be brought into competition with machinery.

II. In muscular animal force the cheapness of animals, or their partial requirement for other duties, and availability at other times for power purposes.

III. In the force of the wind, peculiarly favourable situations where a more regular supply may be relied upon.

IV. In the force of water in motion, its ready storage in certain districts.

The relative values and work performed by each of the above are dealt with in succeeding sections.

Nature further provides the means of operating other machinery, by supplying fuels, which form our only alternative means of obtaining motive power by the generation. of heat in their destruction by fire.

Fuels.

Coal, or lignite,

Mineral oil,

Natural gas,

Timber or peat,

Straw and reeds,

and a further class of waste materials due to processes carried on in a neighbourhood, such as sawdust, cinders, town-refuse, waste gases from furnaces.

Where these exist, or are in any way accessible, their relative prices would be well worth ascertaining, before deciding on the use of one or the other.

Cost of Water. This matter has an important bearing upon the question of the use of several forms of prime motors. Water is required for boilers, but may be condensed and thus used over again. It is, however, necessary to have a supply or reserve for the process of condensation. It is required by gas and petroleum engines to keep the cylinders cool, though in less quantity.

In fact, some water may be considered a necessity in all the heat engines, though, naturally not in the same volume as when utilized to provide force by its own fall.

Comparative Summary.-A summary of the relative values or costs of these natural forces, which are dealt with more fully under their separate sections hereafter, is rather instructive reading, and for a ready estimation, presents the matter in a practical form within a few lines.

The effect of one effective horse-power, of 33,000 pounds raised 1 foot high in a minute, is to be obtained in the following manners:

By men

By animals

By wind

By 12 men working cranks.

By 3 powerful oxen.

By 2 good horses.

By a 16 ft. windmill in a good breeze.

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