My prison--if such it was--was a tolerably spacious affair, measuring about twenty feet long by fifteen feet wide, and it was absolutely empty; also, there being no windows to the building, and the light entering only by the open door, the obscurity, on entering, seemed profound, although a few minutes sufficed to enable one's eyes to grow accustomed to it, when, at least during daylight, it was possible to see clearly enough for all practical purposes.