The book “Studio d‘architettura civile” by Ferdinando Ruggieri is part of ETH‘s RARA Collection and I was able to have a look at it in the archive. The 4 books (tomi) were surprisingly big, with a format of roughly 36 x 48 cm. Therefore the drawings were absolutely fascinating. I also discovered even more beautiful drawings by Ruggieri. I also found out, that some pages are not inked solely in black, but also contain red parts of text.