I was a structural engineer in London which allowed me special access to some buildings and what I found was that the best limestone (fewest defects) was used at street level and as you went up the quality became poorer and poorer until, at roof level, all sorts of shells and other marine debris were clearly visible especially as the limestone binder was dissolved over time
I was a structural engineer in London which allowed me special access to some buildings and what I found was that the best limestone (fewest defects) was used at street level and as you went up the quality became poorer and poorer until, at roof level, all sorts of shells and other marine debris were clearly visible especially as the limestone binder was dissolved over time