A drawing of a fountain designed as a vase placed on top of a column. On the urn kneels a naked child, blowing through water which falls into a basin raised on a smaller column. 

This is one of two fragments probably cut from a single sheet (see also RCIN 912690), with designs for a ‘Heron’s fountain’, a hydraulic curiosity in which a reservoir of water emptying by gravity into a lower chamber sends a small fountain of water back into the upper reservoir. The device gives the impression of being a perpetual motion machine, though eventually the reservoir empties and the fountain stops. 

The designs offer a rare glimpse of Leonardo thinking as a sculptor in a context other than an equestrian monument. Their scale is hard to determine: they were probably table fountains to be cast in bronze or silver, but the columns seem monumental in conception and they could have been full-scale fountains for a garden.