when luther was a boy , cornelius would sit on the porch and take a small bottle of oil from the overalls he wore whether it was a hundred in the shade or there was frost on the woodpile , and he 'd wipe down his tool set , knowing each one by touch and explaining to luther how that was n't no crescent wrench , boy , was a monkey wrench , get it straight , and how any man did n't know the difference by touch alone ought just use the monkey wrench , 'cause a monkey what he be .