Brick won't work, if you're going to build a wall, you have to plaster it on the outside, otherwise after ten or twenty years those bricks will loosen.,He was going to the quarry to see if they also used copper coins for transactions. If so, he would take his silver and exchange it for copper coins first, then use the copper coins to pay, making a profit on the difference.,He pulled out another thin slate and showed it to everyone: "There are also these kinds. The foreman at the quarry said that these slates can be used for heating floors."。