CONVERSION TABLES. By means of the tables on pages 8 and 9, metric measures can be converted into English, and vice versa, by simple addition. All the figures of the values given are not required, four or five digits being all that are commonly used; it is only in very exact calculations that all the digits are necessary. Using table, proceed as follows: 1,828.8 Change 6,471.8 feet into meters. Any number, as

121.92 6,471.8, may be regarded as 6,000 + 400 + 70 +1

21.336 +.8; also, 6,000 - 1,000 X 6; 400 = 100 X 4, etc.

.3048 Hence, looking in the left-hand column of the

.2438 upper table, page 39, for figure 6 (the first figure of 1,972.6046 the given number), we find opposite it in the third column, which is headed “Feet to Meters," the number 1.8287838. Now, using but five digits and increasing the fifth digit by 1 (since the next is greater than 5), we get 1.8288. In other words, 6 feet = 1.8288 meters; hence, 6,000 feet 1,000 x 1.8288 = 1,828.8, simply moving the decimal point three places to the right. Likewise, 400 feet == 121.92 meters; 70 feet

21.336 meters; 1 foot = .3048 meter, and .8 foot = .2438 meter. Adding as shown above, we get 1,972.6016 meters. Again, convert 19.635 kilos into pounds. The

22.046 work should be perfectly clear from the explana

19.8416 tion given above. The result is 43.2875 pounds.

1.3228 The only difficulty in applying these tables lies

.0661 in locating the decimal point; it may always be

.0110 found thus: If the figure considered lies to the left

43.2875 of the decimal point, count each figure in order, beginning with units (but calling unit's place zero), until the desired figure is reached, then move the decimal point to the right as many places as the figure being considered is to the left of the unit figure. Thus, in the first case above, 6 lies three places to the left of 1, which is in unit's place; hence, the decimal point is moved three places to the right. By exchanging the words "right” and “left," the statement will also apply to decimals. Thus, in the second case above, the 5 lies three places to the right of unit's place; hence, the decimal point in the number taken from the table is moved three places to the left.

1,550.03092 10.7641034 35.3156163.001422310 3,100.06184 21.5282068 70.6312326 .002844620 4,650.09276 32.2923102 105.9468489 .004266930 6,200.12368 43.0564136 141.2624652.005689240 7,750.15460 53.8205170 176.5780815 .007111550 9,300.18552 64.5846204 211.8936978 .008533860 10,850.21644 75.3487238 247.2093141 .009956170 12,400.24736 86.1128272 282.5249304 .001378480 13,950.27828 96.8769306 317.8405467 .012800790 15,500.30920 | 107.6410340 353.1561630 .014223100

SPECIFIC GRAVITIES AND WEIGHTS.

The specific gravity of a solid or liquid body is the ratio between its weight and that of a like volume of distilled water. If the solid is of irregular shape, its specific gravity may be found by weighing it in air and in water; the loss of weight in water is the weight of an equal volume of water; hence, if Wis the weight in air, and W' the weight in water,

W the specific gravity is

W – wi
The weight of water in various conditions is as follows:

Water, pure at 320 F, weighs 62.417 lb. per cu. ft.
Water, pure at 390 F. weighs 62.425 lb. per cu. ft.
Water, pure at 62° F. weighs 62.355 lb. per cu. ft.
Water, pure at 212° F. weighs 59.700 lb. per cu. ft.
Water, sea..

.weighs 64.080 lb. per cu. ft.
Ice

weighs 57.400 lb. per cu. ft. Snow, fresh

weighs 5 to 12 lb. per cu. ft. Snow, wet... ...weighs 15 to 50 lb. per cu. ft.

METALS.

Name of Metal.

Weight per Cui. In. Pounds.

Weight per Cu.Ft. Pounds.

Specific Gravity.

Aluminum..
Antimony
Bismuth
Brass, cast
Brass, rolled
Bronze (gun metal)
Copper, cast
Copper, rolled
Gold, 24 carat
Iron, cast
Iron, wrought
Lead, commercial
Mercury, 60° F.
Platinum
Silver
Steel
Tin, cast
Zinc

BUILDING MATERIALS, ETC.

Name of Material.

Weight per Cu.Ft. Pounds.

Specific Gravity.

160 150 125 156 15-30

119 23-32 93.5 54 84 50

140 80-100

56 82-92 90-100 75-100

186 157 170

2.56 2.40 2.00 2.50 .24-.48

1.90 .37-.51 1.50

.865 1.35

.80 2.25 1.44

.89 1.36 1.52 1.31 2.98 2.52 2.72

Bluestone
Brick, pressed
Brick, common.
Chalk
Charcoal
Clay, compact
Coke, loose.
Coal, hard, solid
Coal, hard, broken
Coal, soft, solid
Coal, soft, broken.
Concrete, cement
Cement, Portland
Cement, Rosendale.
Earth, dry, shaken
Earth, rammed
Earth, moist, shaken.
Glass, average
Glass, common window
Granite.
Gravel (see sand)
Limestones and marbles.
Lime, quick
Marble (see limestone).
Plaster of Paris
Porphyry
Quartz
Sand
Sandstone
Shales
Slate
Trap rock

Masonry.
Common brickwork, cement mortar
Common brickwork, lime mortar.
Granite or limestone rubble, dry
Granite or limestone rubble
Granite or limestone, well dressed
Mortar, hardened
Pressed brickwork
Sandstone rubble