To find how much Powder will fill a Shell.

Multiply the cube of the interior diameter in inches by .01744. EXAMPLE.-How much powder will fill a shell, the internal diameter being 9 inches?

Thickness of staves and heads

Weight of barrels about

Proof of Powder. One oz. with a 24 lb. ball. The mean range of new, proved at any one time, must not be less than 250 yards; but none ranging below 225 yards is received.

Powder in magazines that does not range over 180 yards is considered unserviceable.

Good powder averages from 280 to 300 yards; small grain from 300 to 320 yards. The greatest initial velocity is obtained by powder of great specific gravity and of very coarse grain, giving 130 grains to 10 grains troy.

LIGHT.

LIGHT is similar to caloric in many of its qualities, being emitted in the form of rays, and subject to the same laws of reflection.

It is of two kinds, Natural and Artificial; the one proceeding from the sun and stars, the other from heated bodies.

Solids shine in the dark only when heated from 6000 to 700°, and in daylight when the temperature reaches 10000.

Relative intensity of light from the burning of various bodies is, for wax, 101 parts; tallow, 100; oil in an Argand lamp, 110; in a common lamp, 129; and an ill-snuffed candle, 229.

By experiments on coal gas, it appears that above 20 cubic feet are required to produce light equal in duration and in illuminating powers to a pound of tallow candles, six to a pound, set up and burned out one after the other.

In distilling 56 lbs. coal, the quantity of gas produced in cubic feet when the distillation was effected in 3 hours was 41.3, in 7 hours 37.5, in 20 hours 33.5, and in 25 hours 31.7.

TONNAGE.

By a law of Congress, the tonnage of vessels is found as follows:

FOR A DOUBLE-DECKED.

Take the length from the fore part of the stem to the after side of the sternpost above the upper deck; the breadth at the broadest part above the main wales; half of this breadth must be taken as the depth of the vessel; then deduct from the length of the breadth, multiply the remainder by the breadth, and the product by the depth; divide this last product by 95, and the quotient is the tonnage.

EXAMPLE. What is the tonnage of a ship of the line, measuring, as above, 210 feet on deck, and 59 feet in breath?

59-2= 29.5, depth.

210-3 of 59=174.6×59×29.5÷953198.8 tons.

FOR A SINGLE-DECKED.

Take the length and breadth as above directed for a double-decked, and deduct from the length of the breadth; take the depth from the under side of the deck-plank to the ceiling of the hold; then proceed as before.

EXAMPLE. The length of a vessel is (as above) 223 feet, the breadth 39 feet, and the depth of hold 23 feet; what is the tonnage?

223 of 39.5:

199.3×39.5×23.5951947.3 tons.

A ton will stow 3 bales cotton.

NOTE.-The burden of similar ships are to each other as the cubes of their like dimensions.

CARPENTERS' MEASUREMENT.

FOR A SINGLE-DECKED.

Multiply the length of keel, the breadth of beam, and the depth of the hold together, and divide by 95.

FOR A DOUBLE-DECKED.

Multiply as above, taking half the breadth of beam for the depth of the hold, and divide by 95.

To find the Tonnage of English Vessels.

RULE. Divide the length of the upper deck between the afterpart of the stem and the forepart of the sternpost into 6 equal parts, and note the foremost, middle, and aftermost points of division. Measure the depths at these three points in feet, and tenths of a foot, also the depths from the under side of the upper deck to the ceiling at the limber strake; or, in case of a break in the upper deck, from a line stretched in continuation of the deck. For the breadths, divide each depth into 5 equal parts, and measure the inside breadths at the following points, viz.: at and at from the upper deck of the foremost and aftermost depths, and at 3 and from the upper deck of the midship depth. Take the length, at half the midship depth, from the afterpart of the stem to the forepart of the sternpost.

Then, to twice the midship depth, add the foremost and aftermost depths for the sum of the depths; and add together the foremost upper and lower breadths, 3 times the upper breadth with the lower breadth at the midship, and the upper and twice the lower breadth at the after division for the sum of the breadths.

Multiply together the sum of the depths, the sum of the breadths, and the length, and divide the product by 3500, which will give the number of tons, or register. If the vessel have a poop or half-deck, or a break in the upper deck, measure the inside mean length, breadth, and height of such part thereof as may be included within the bulkhead; multiply these three measurements together, and divide the product by 92.4. The quotient will be the number of tons to be added to the result as above found.

For Open Vessels. The depths are to be taken from the upper edge of the upper strake.

For Steam Vessels. The tonnage due to the engine-room is deducted from the total tonnage calculated by the above rule.

To determine this, measure the inside length of the engine-room from the foremost to the aftermost bulkhead; then multiply this length by the midship depth of the vessel, and the product by the inside midship breadth at 0.40 of the depth from the deck, and divide the final product by 92.4. S

PILING OF BALLS AND SHELLS.

To find the Number of Balls in a Triangular Pile. RULE.-Multiply continually together the number of balls in one side of the bottom row, and that number increased by 1; also, the same number increased by 2; of the product will be the answer. EXAMPLE. What is the number of balls in a pile, each side of the base containing 30 balls?

30x31x3264960, Ans.

To find the Number of Balls in a Square Pile.

RULE.-Multiply continually together the number in one side of the bottom course, that number increased by 1, and double the same number increased by 1; of the product will be the answer. EXAMPLE.-How many balls are there in a pile of 30 rows? 30×31×61-6=9455, Ans.

To find the Number of Balls in an Oblong Pile.

RULE. From 3 times the number in the length of the base row subtract one less than the breadth of the same; multiply the remainder by the same breadth, and the product by one more than the same, and divide by 6.

EXAMPLE.-Required the number of balls in an oblong pile, the numbers in the base row being 16 and 7?

16×3-7-1x7x7+1÷6= 392, Ans.

To find the Number of Balls in an Incomplete Pile.

RULE. From the number in the pile, considered as complete, subtract the number conceived to be in the upper pile which is wanting.

WEIGHT AND DIMENSIONS OF BALLS AND SHELLS. 207

WEIGHT AND DIMENSIONS OF BALLS AND SHELLS.

THE Weights of these may be found by the rules in Mensuration; also, in the tables, pages 233, 236, and 255.

To find the Weight of an Iron Ball from its Diameter.

An iron ball of 4 inches diameter weighs 8.736 lbs.

8.736

64

Therefore,

of the cube of the diameter is the weight, for the weight of spheres is as the cubes of the diameters.

EXAMPLE-What is the weight of a ball 10 inches in diameter ?

To find the Diameter from the Weight.

EXAMPLE.-What is the diameter of an iron ball, its weight being 99.5 lbs. ?

Or, multiply the cube of the diameter in inches by .1365, and the sum is the weight. And divide the weight in pounds by .1365, and the cube root of the product is the diameter.

To find the Weight of a Leaden Ball.

A leaden ball of 4 inches diameter weighs 13.744 lbs. Therefore, of the diameter is the weight.

13.744

61

EXAMPLE. What is the weight of a leaden ball 10 inches in diameter?

Or, multiply the cube of the diameter in inches by .2147, and the sum is the weight. And divide the weight in pounds by .2147, and the cube root of the product is the diameter.

To find the Weight of a Cast Iron Shell.

Multiply the difference of the cubes of the exterior and interior diameter in inches by .1365.

EXAMPLE. What is the weight of a shell having 10 and 8.50 inches for its diameters?

103-8.53X.136552.6 lbs., Ans.