Brick

Ancient bricks were sun-dried and larger than modern kinds, which are ab. 2x2x8+ inches in size and weigh ab. 4 lbs. Pre ed brick will weigh ten per cent more. The average compre ive strength is ab. 2,500 lbs. per sq. inch, but the best kinds are five times as strong. A common dry brick will often absorb water equal to one-third of its volume or one seventh of its weight. Three qualities are taken from the kiln; the arch brick, which is near the flames, is hard and often weak and brittle; the body brick, from the interior of the kiln, is of the best quality; the soft are those from the top of the pile.