1. What will be the weight of a hollow ball or shell of cast iron, the external diameter being 94 and internal diameter 8 inches? Opposite 9 are 118.06, and Opposite 8 are 92.24, subtract 25.82 lbs., weight required. 2. Requiring to remove a cast-iron ball 37.8 lbs. in weight, and in diameter 6 inches, and replace it by one of lead of an equal weight, what must be the diameter of the leaden ball? Weight of lead to that of cast iron=1.56 (see Table, page 110). 6.53 Then =3√176=5.6 inches, the diameter. 1.56 Application and Use of the Table. 1. Required the number of square feet in a board or plank 16 feet in length and 9 inches in breadth. Opposite 9 is 8125 × 16.5=134 square feet. 2. A board 1 foot 2 inches in breadth and 21 feet in length; what is its superficial content in square feet? Opposite 2 is 2292, to which add the 1 foot; then 3. In a board 15 the other, and 14 feet? 15.5+9 2 = inches at one end, 9 inches at feet in length, how many square -124, or 1·0208; and 1·0208 × 14.5=14.8 sq. ft, 2. Cubic or Solid Measure. In the cubic estimation of timber, custom has established the rule of the mean girt being the side of the square considered as the cross sectional dimensions; hence, multiply the number of cubic feet per lineal foot as in the Table of Cubic Measure opposite the girt, and the product is the solidity of the given dimensions in cubic feet. Suppose the mean girt of a tree 21 inches, and its length 16 feet, what are its contents in cubic feet? 3.136 × 16-50-176 cubic feet. Battens, Deals, and Planks, as imported into this country, are each similar in their various lengths, but differing in their widths and thicknesses, and hence their principal distinction: thus, a batten is 7 inches by 21-a deal 9 by 3,--and a plank 11 by 3,-these being what are termed the standard dimensions, by which they are bought and sold, the length of each being taken at 12 feet; therefore, in estimating for the proper value of any quantity, nothing more is required than their lineal dimensions, by which to ascertain the number of times 12 feet there are in the given whole. Suppose I wish to purchase the following: |