Solomon thought that still more vigour than is required to separate the hard husk or bran from wheat would fail to separate "a fool from his folly." "Though thou shouldst bray a fool in a mortar among wheat with a pestle, _yet_ will not his foolishness depart from him." The rainbow, in some parts, is called the "pestle of the Barimo," or gods.

Boys and girls, by constant practice with the pestle, are able to plant stakes in the ground by a somewhat similar action, in erecting a hut, so deftly that they never miss the first hole made.
Let any one try by repeatedly jobbing a pole with all his force to make a deep hole in the ground, and he will understand how difficult it is always to strike it into the same spot.
As we were sleeping one night outside a hut, but near enough to hear what was going on within, an anxious mother began to grind her corn about two o'clock in the morning.

"Ma," inquired a little girl, "why grind in the dark ?" Mamma advised sleep, and administered material for a sweet dream to her darling, by saying, "I grind meal to buy a cloth from the strangers, which will make you look a little lady." An observer of these primitive races is struck continually with such little trivial touches of genuine human nature.
The mill consists of a block of granite, syenite, or even mica schist, fifteen or eighteen inches square and five or six thick, with a piece of quartz or other hard rock about the size of a half brick, one side of which has a convex surface, and fits into a concave hollow in the larger and stationary stone.

The workwoman kneeling, grasps this upper millstone with both hands, and works it backwards and forwards in the hollow of the lower millstone, in the same way that a baker works his dough, when pressing it and pushing from him.

The weight of the person is brought to bear on the movable stone, and while it is pressed and pushed forwards and backwards, one hand supplies every now and then a little grain to be thus at first bruised and then ground on the lower stone, which is placed on the slope so that the meal when ground falls on to a skin or mat spread for the purpose.