When I came to build my chimney I studied masonry. My bricks, being secondhand ones, required to be cleaned with a trowel, so that I learned more than usual of the qualities of bricks and trowels. The mortar on them was fifty years old, and was said to be still growing harder; but this is one of those sayings which men love to repeat whether they are true or not. Such sayings themselves grow harder and adhere more firmly with age, and it would take many blows with a trowel to clean an old wiseacre of them. Many of the villages of Mesopotamia are built of secondhand bricks of a very good quality, obtained from the ruins of Babylon, and the cement on them is older and probably harder still. However that may be, I was struck by the peculiar toughness of the steel which bore so many violent blows without being worn out. As my bricks had been in a chimney before, though I did not read the name of Nebuchadnezzar on them, I picked out as many fireplace bricks as I could find, to save work and waste, and I filled the spaces between the bricks about the fireplace with stones from the pond shore, and also made my mortar with the white sand from the same place. I lingered most about the fireplace, as the most vital part of the house.