Vitruvius Quote

With regard to burnt brick... If not made of good clay or if not baked sufficiently, it shows itself defective... when exposed to frosts and rime. Brick that will not stand exposure on roofs can never be strong enough to carry its load in a wall. Hence the strongest burnt brick walls are those which are constructed out of old roofing tiles.

Chapter VIII, Sec. 19 - De architectura (The Ten Books On Architecture) (~ 15BC) - Book II

With regard to burnt brick... If not made of good clay or if not baked sufficiently, it shows itself defective... when exposed to frosts and rime....

With regard to burnt brick... If not made of good clay or if not baked sufficiently, it shows itself defective... when exposed to frosts and rime....

With regard to burnt brick... If not made of good clay or if not baked sufficiently, it shows itself defective... when exposed to frosts and rime....

With regard to burnt brick... If not made of good clay or if not baked sufficiently, it shows itself defective... when exposed to frosts and rime....