"On recto: two artists are shown, drawing. Three men at the bottom of the falls. Houses of Tivoli visible at the top. Framing line and caption: ""Tivoli 10 – la grotto della sirena;"" ""20"" at the top. On verso: sketches for ceiling with fifteen panels, quarter of a ceiling with winged genii, plant candelabra, three curved friezes with grotesque animals. ""21"" above."