TABLE

Containing the weight of a Square Foot of Copper and Lead in lbs. avoirdupois, from 3 to an inch in thickness, advancing by 32

Of the Weight of a Square Foot of Sheet Iron in lbs. avoirdupois, the thickness being the number on the wire gauge.-No. 1 is of an inch; No. 4. ; No. 11, f, &c.

Of the Weight of a Square Foot of Boiler Plate Iron, from 1 to 1 inch thick, in lbs. avoirdupois.

5 7.5 10 12.5 15 17.5 20 22.5 25 27 530 32.5 35 37.5 40

TABLE

Showing the Quantity of Water per Linear Foot in Pumps, or Vertical Pipes of different Diameters,

Examples illustrative of the Utility of the Table.

1. Required the quantity of water lifted by each stroke of the bucket of a 9-inch pump, the length of the stroke being 24 feet. 3:068 x 2.25 - = 6.903 gallons, each stroke.

2 What length of stroke with a 6-inch pump will be necessary to discharge 44 gallons of water per minute, the number of strokes being 18 in the given time?

3. What must be the diameter capable of raising 25 cubic feet of water per minute, the length of the stroke being 24 feet, and making 16 effective strokes per minute?

Properties of Atmospheric Air.-It is by the oxygen of the atmosphere that combustion is supported. The common combustibles of nature are chiefly compounds of carbon and hydrogen, which, during combustion, combine with the oxygen of the atmosphere, and are converted into carbonic acid and watery vapor, different species of fuel requiring different quantities of oxygen. The quantity required for the combustion of a pound of coal varies from two to three lbs. Sixty cubic feet of atmospheric air will produce 1 lb. of oxygen.

The pressure or fluid properties of the atmosphere oppose bodies in passing through it, the opposing resistance increasing as the square of the velocity of the body, and the resistance per square foot in lbs. as its velocity in feet per second, multiplied into 002288. Thus, suppose a locomotive engine in a still atmosphere, at a velocity of 25 miles per hour, presents a resisting frontage of 20 feet; required the amount of opposing resistance at that velocity.

25 miles per hour equal 36 67 feet per second.

Then 36-673× 002288 × 20 = 61·5 lbs., constant opposing force.

TABLE

Showing the Number of Threads to an Inch in V-thread Screws.

Diam. in inches, 576 ±

16

1

111118

The depth of the threads should be half their pitch. The diameter of a screw, to work in the teeth of a wheel, should be such that the angle of the threads does not exceed 10°.

TABLE

Of the component parts of one English pound avoirdupois of 7000 grains of the following varieties of Wood. [MUSHET.]

TABLE

Of Change Wheels for Screw-cutting; the leading Screw being of inch pitch, or containing 2 threads in an inch.

Temperature and Weight of the Atmosphere at various heights.