Cannons were very heavy and the carriages used to transport them were often unwieldy. Leonardo deigned a structure that could be easily dismantled and transported, thus permitting the cannon to be easily moved about.
The Springald, a device that throws large bolts or stones resembles a contemporary crossbow with inward swinging arms. Examples of springalds were drawn by Leonardo da Vinci during a period when he was also drawing powder-propelled weapons. Though several reconstructed examples can be found, there are no known archaeological finds of these machines. It is quite probable that this is because materials used to make them were recycled when they were no longer useful.
