« ΠροηγούμενηΣυνέχεια »
ART. 14. To find the tonnage of a ship. RUH,F). Multiply the ength of the keel by the breadth of the beam, and that pro, act by the depth of the hold, and divide the last product by §5, and the quotient is the tonnage. £: AX! P. F.
Suppose a ship 72 feet by the keel, and 34 feet by the beam, and 12 feet deep ; \; sat is the tootage 2 ox24× 12-3-95-213,2+ ions. Ans. H: ... . . Multiply the length of the keel by the breadth of the beam, and that product by liaif the breadth of the beam, and divide by 95. EXAMPLE.
A ship 84 feet by the keel, 28 feet by the beam; what is the tonnage P 84×28×14--95=350,29 tons. Jims. ART. 15. From the proof of any cable, to find the strength of another.
RULE. The strength of cables, and consequently the weights of their anchors, are as the cube of their peripheries. Therefore; As the cube of the periphery of any cable, Is to the weight of its anchor; So is the cube of the periphery of any other cable, To the weight of its anchor. to, YA M PI. F.S. 1. If a cable 6 inches about, require an anchor of 24 cwt. of what weight must an anchot be for a 12inch cable 2 As 6×6×6 : 2+cuet. : : 12×12×12 : 18¢ott. Jins. 2. If a 12 inch cable require an anchor of 18 cwt. what must the circumference of a cabie be, for an anchor of 23 cwt. * c:ct. cwt. 2??. As 13 : 12×12×12 : : 2,25: 216 &/216=6 .ins.
AR r. 16. Having the dimensions of two similar built ships of a different owpacity, with the burthen of one of it, sin, to find the burther of the other,
RULE. The burthens of similar built ships are to each otier, as the cubes of their like dimensions.
If a ship of 300 tons burthen be 75 feet long in the ke, I demand the burthen of anotier shir, whose keel is ! feet long?
T.cut.grs.li. As 75x75x15 : 500::100X100X100 :7110 Sijo
CROSS MULTIPLICATION, Is a rule made use of by workmen and artificers in case ing up the contents of their werk.
RULE. 1. Untier the multiplicand write the corresponding de nominations of the multiplier.
2. Aluliiply cach term into the multiplicand, beginni: at the lowest by the highest generation in the mal plier, and write the l'esult if each under its respect terin ; ubserving to carry mnifer every 12, from ea lower cierromination to its next superior.
S. 11! the same manner multiply all the multiplica; by the inches, or second lenomination, in the multipli and sei the result of each terin one place remove:l to: right hand of those in the inalliplican...
1. Do the same with the seconds in t'ie multiplier, iing the result of each terin two places to the right hai? of those in the multiplicand, &c.
FEET, INCHES AND SEco Nips.
F. I. It
How many square feet in a board 16 feet 9 inches long, and 2 feet 3 inclics wide :
y Duodecimals. By Poeciutais.
F. R. "
sons. $7 8 3 *** * * * ARs. 37,6875–37 8 S
TO MEASURE LOADS OF WOOD.
RULE. Multiply the length by the breadth, and the product by the depth or height, which will give the content in solid feet; of which 64 make half a cord, and 128 a cord. How many
solid feet are contained in a load of wood, 7 feet 6 inches long, 4 feet 2 inches wide, and 2 feet 3 inches high?
7 ft. 6'in.=7,5 and 4 ft. 2 in.=4,167 and 2 ft. 3 inz 2,25; then, 7,5X4,167=S1,9525 X 9,95=70,318125 solid feet, Aris.
But loads of wood are commonly estimated by the foots allowing the load to be 8 feet long, 4 feet wide, and then 2 feet high will make half a cord, which is called 4 feet of wood; but if the breadth of the load be less than 4 feety its height must be increased so as to make half a cord, which is still called 4 feet of wood.
By measuring the breadth and heighth of the Toad, the content may be found by the following
RULE. Multiply the breadth by the height, and half the product will be the content in feet and inches.
Required the content of a load of wood which is 3 feet 9 inches wide and 2 feet 6 inches ligh. By Duodecimals. By Decimcls. F.in.
F. 3 9
3,75 2 6
1 10 6
9 4 6 9,375
F. in. ans. 4 8 S 4,6875=4 81, or half a cord and
81 inches over. the foregoing method is concise and easy to those who are well -equainted with Duodecimals, but the following Table will give the content of any load of wood, by inspection only, sufficiently emot For command practico ; whicb will be found very convenient.
- TG L 5 e o is E FOREGO i NG TABLE. First measure the breadth and height of your load to the nearest average inch : then find the $readth in the left hand column of the table; then Love to the right on the same line till you come under the height in feet, and you will have the content in inches, answering the feet, to which add the cortent of the inches on the right and divide the sum by 12, and you will have the true content of the load in feet and inches. Note.—The contents answering the inches being always small, may be added by inspection. EXAMPLES. 1. Admit a load of wood is 3 feet 4 inches wide, and 2 feet 10 inches high; required the content.— Thus, against 3 ft. 4 inches, and under 3 feet, stands 40 inches; and under 10 inches at top, stands 17 inches: then 40+ 17=57 true content in inches, which divide by 12 gives 4 feet 9 inches, the answer. 2. The breadth being 3 feet, and height 2 feet 8 inches; required the content.— hus, with breadth 5 feet 0 inches, and under 2 feet