On windows in roofs

THE more usual windows in northern buildings, especially houses with fireplaces, are set in the sloping roofs, through which clearer light comes down from the sky.¹ They are made of glass or oilcloth² to keep out the rain. But in cities houses have iron gratings and bars at the side because of the narrower streets. The doors of the people who live at the farthest frontiers of the realm are purposely made narrow and low,³ to ensure that they do not afford easy access to robbers and unfriendly individuals; and certainly, to oppose these and other avowed enemies they have walls with loopholes for shooting arrows.