Military Engineering Exploits - Mowing Wagon

Both these drawings date from around 1485, when Leonardo was working for the Duke of Milan as an artist and military strategist.
In the bottom drawing, the horses pulling the war chariot are protected by whirling scythes, which are turned by an elaborate system of gears connected to the chariot's wheels. The horses could only charge straight ahead within the confines of the machine.
Leonardo recognised that under battle conditions, the horses would probably become frightened and bolt.