To find the Government Tonnage. "If the vessel be double-decked, take the length thereof from the fore part of the main stem, to the after part of the stern post, above the upper deck; the breadth thereof at the broadest part above the main wales, half of which breadth shall be accounted the depth of such vessel, and then deduct from the length, three-fifths of the breadth, multiply the remainder by the breadth and the product by the depth, and divide this last product by 95, the quotient whereof shall be deemed the true contents or tonnage of such ship or vessel; and if such ship or vessel be single-decked, take the length and breadth, as above directed, deduct from the said length three-fifths of the breadth, and take the depth from the under side of the deck plank to the ceiling in the hold, then multiply and divide as aforesaid, and the quotent shall be deemed the tonnage." EXAMPLES. 1. What is the government tonnage of a single-decked vessel, whose length is 69 feet 6 inches, breadth 22 feet 6 inches, and depth 8 feet 6 inches ? of 22 6: 13 6 69 6-13 6=56 0 2. What is the government tonnage of a double-decked vessel, of the following dimensions, length 75 feet 6 inches, breadth 23 feet 4 inches, and depth 11 feet 8 inches? of 23 414 0 61 6×23 4×11 8 = 16741 =176 tons. 95 The tonnage may be found by using a table of logarithms, the inches being reduced to decimals, as in the following example. What is the government tonnage of the ship London, the keel of which is 112 feet and the beam 28 feet 7 inches? Keel. 38 feet Beam. Hold. Tons. 95ths. 15 ft. 8 ins. 5 ft. 6 ins. Single Deck 34 44 TABLES OF CORDAGE. A CORDAGE TABLE, showing how many fathoms, feet, and inches of a Rope, of any size, not more than 14 inches, make a hundred weight; with the use of the Table. At the top of the table, marked inches, fathoms, feet, inches, the first column is the thickness of the rope in inches and quarters; and the other three, the fathoms, feet, and inches, that make up a hundred weight of such a rope. One example will make it plain : Suppose you desire to know how much of a seven-inch rope will make a hundred weight; find 7 in the third column under inches, or thickness of rope, and against it in the fourth column you find 9, 5, 6, which shows that there will be 9 fathoms, 5 feet, and 6 inches, required to make up one hundred weight. A TABLE, showing the weight of any Cable or Rope, of 120 fathoms in length, and for every half inch, from 3 to 24 inches in circumference. The first column, marked for inches, is the thickness or circumference of the cable, to every inch, from 3 to 24 inches; the second is marked cwt. qrs. for the hundred weights and quarters that it will weigh if 120 fathoms in length. For instance: Suppose it be a cable of 141⁄2 inches; look against 14, and you will find in the other column 52 cwt. 2 qrs., which shows that 120 fathoms of 14 inch cable will weigh 52 cwt. 2 qrs., and so in others; and any quantity of a less length will weigh in proportion. A ship was brought to anchor in a gale of wind; but the gale increasing, it was thought safest to cut the cables, in consequence of which 75 fathoms of 16 inches, and 50 fathoms of 12 inches were lost; what must they be valued at in calculating the average, new cordage being then 14 dollars per cwt.? A TABLE, showing the weight of Iron Cables of 90 fathoms ; and also the comparative strength of Iron and Hemp Cables. Iron. At 13 inch 12 11 13 Hemp. =17 inches, and weighs 123 2008 7 61 12 1 1 GEOGRAPHICAL QUESTIONS. A TABLE, showing the number of miles contained in a Degree of Longitude, in each Parallel of Latitude, from the Equator to the Poles. |