If it be desired to find the square feet in a board which is longer than 20 feet, take the square feet in two shorter boards, the added lengths of which are equal to the length of the board which you wish to measure; for instance, if the hoard be 26 feet long by 19 inches wide, add together the square feet in a 20-foot and a 6-foot board, each 19 inches wide? 31 feet 8 inches -+- 9 feet 6 inches = 41 feet 2 inches.

To reckon the square feet in a board, multiply the width in inches by the length in feet, and divide this result by 12, which gives the number of square feet it contains.

To reckon the square feet in timber, multiply the width in inches by the thickness, and this result by the length in feet. This result divided by 12 gives the number of square feet contained in the piece of timber.

Shingles. - A bundle of shingles, if full size, should have 25 courses on each end, and be 20 inches wide; or else have 22 courses on one end, and 23 courses on the other, and be 22 inches wide. Four such bundles contain 1,000 shingles, each supposed to be 4 inches wide. They are usually 10 inches long; sometimes in the nicest class of shingles, they come 18 inches long. It is poor economy to use an inferior quality of shingles; it costs rather more to lay them than it does good ones, and they make a leak)7 roof, almost from the first. Spruce shingles are used considerably by some, but are not suitable to make a good roof, as they warp and twist, and very quickly split to pieces. Some soft pine or cedar shingles, best quality, are the cheapest in the end: but even bundles of the best quality will contain some hard, glassy shingles, which will act almost as badly as spruce; they should be thrown out.

It takes about 5 pounds of four-penny nails per thousand shingles; or 3 or 4 pounds of three-penny coarse, which we think are preferable.

One thousand shingles, laid 4 inches to the weather, will cover 111 square feet. One thousand shingles, laid 4^ inches to the weather, will cover 125 square feet. One thousand shingles, laid 5 inches to the weather, will cover 139 square feet. One thousand shingles (18-inch shingles only, except on walls), laid 5£ inches to the weather, will cover 153 square feet.

The above does not include waste, which must be allowed.

Laths are 4 feet long, and come in bundles of 100 each.

(We have seen some lots, the bundles of which were short some 20 or 30 laths.) Ten bundles make 1,000, which will cover about 60 square yards, which requires about 7 pounds of three-penny fine nails.

Clapboards are usually 4 feet long, and come 25 in a bundle; 4 bundles making a hundred, which requires about 3J pounds of five-penny nails. One hundred clapboards, laid 4 inches to the weather, will cover 133 square feet. One hundred clapboards, laid 4 1/2 inches to the weather, will cover 150 square feet. This does not include waste, which must be allowed.

Sandpaper, - No. 00, too fine. No. 0, too fine. No. 1/2, fine enough for rubbing down paint or shellac. No. 1, fine for carpenters. No. l 1/2, generally used. No. 2, too coarse.

Sheet Lead and Zinc for Flashings. - Sheet lead 1/32 inch thick weighs 2 pounds per square foot; 3/64 inch thick, weighs 3 pounds per square foot (generally used); 1/16 inch thick, weighs 4 pounds per square foot; 3/32 inch thick, weighs G pounds per square foot; 1/8 inch thick, weighs 8 pounds per square foot. Sheet zinc comes in sheets 3x7 feet. A sheet of No. 9 zinc (commonly used) weighs 14 pounds, that is, about 2/3 pounds per square foot.

To bend a Gooseneck. - Fill the lead pipe full of sand, ram it in well and plug up both ends, bend it carefully over your knee, or around a barrel or smooth tree.

To bend Brass or Copper Pipes. - Fill them with melted rosin, bend carefully, and then melt out the rosin.