we have

D = √([200(2 + 1½)2]
0.7854)4
3,

Now 1 + 1½ = 5
2 and (5
2)2 is 25
4,

also, 200 × 25
4 = 1250,

1250 × 4
3 = 1666,

1666 ÷ 0.7854 = 2121,

finally, √2121 = 446 very nearly.

C.
WEIGHTS AND MEASURES.

Name of material.Weight per cubic foot.
Air0.077 lbs.
Earth112. lbs.
Water62.5 lbs.
Ice58.0 lbs.
Sand132.0 lbs.
Clay120.0 lbs.
Chalk155.0 lbs.
Brick110.0 lbs.See Chap. XI., masonry.
Brickwork95.0 lbs.
Dry mortar96.0 lbs.
Sandstone140.0 lbs.
Limestone142.0 lbs.Average 86 to 198.
Granite175.0 lbs.
Coal, Bituminous60 to 80.0 lbs.
Coal, Anthracite85 to 95.0 lbs.
Coke50 to 65.0 lbs.
Coal, Cannel75 to 80.0 lbs.
Wrought Iron480.0 lbs.
Cast-Iron450.0 lbs.
Steel487.0 lbs.
Hard Wood.
Green62.0 lbs.
Air dried46.0 lbs.
Kiln dried40.0 lbs.
Soft Wood.
Green53.0 lbs.
Air dried30.0 lbs.
Kiln dried28.0 lbs.
Weight per bushel.
Wheat60 lbs.
Corn on the cob70 lbs.
Corn, shelled56 lbs.
Rye56 lbs.
Oats35 lbs.
Barley47 lbs.
Potatoes, Irish60 lbs.
Potatoes, Sweet55 lbs.
Beans, White60 lbs.
Beans, Castor46 lbs.
Bran20 lbs.
Clover Seed60 lbs.
Timothy45 lbs.
Hemp44 lbs.
Flax56 lbs.
Buckwheat52 lbs.
Peaches, Dried33 lbs.
Apples, Dried24 lbs.
Onions57 lbs.
Salt, Coarse50 lbs.
Malt38 lbs.
Corn Meal48 lbs.
Salt, Fine55 lbs.

D.
VALUE OF THE BIRMINGHAM GAUGES.