April 15th: Birth of Leonardo da Vinci

Leonardo da Vinci was born on this date in 1452. The famous artist and polymath was a brilliant inventor - many of his inventions and ideas were forerunners of things which were not built until centuries later.

10 things Leonardo da Vinci invented:

1. Flying machines: "Ornithopter" - a machine consisting of wings shaped like those of a bat, and a board on which the pilot would lie and power the machine by pedalling, and cranking a handle for extra power. The wings would actually rotate and flap, as birds wings do. Scientists reckon it would have flown, getting it into the air would be a problem as the pilot would not be able to generate enough power to achieve take off; Aerial screw - which would work using the same principles that make helicopters fly today. It was a linen and wire helically shaped contraption powered by four men standing on a platform and turning crank handles. Although he got the scientific theory right, scientists today believe it would have been too heavy to fly.
2. Weapons: Although da Vinci hated war, he was enough of a pragmatist to realise that inventing war machines was what put the food on the table. The kings and princes of the time were willing to pay handsomely for devices that would give them an advantage in battle. The 33 barrelled organ was basically a machine gun consisting of 33 small cannons connected together which could be fired in groups of 11 - while one group was being fired, another was cooling and another was being loaded; He invented an armoured car, basically a round platform with a slanted protective cover with eight men cranking handles to make it move. It was also equipped with cannons so it could move and fire in all directions. It had a major design flaw, though. Because of the orientation of the cranks, it could go in every direction except forwards. It's possible that da Vinci did this on purpose so that it would never actually be used. cannon; crossbow
3. Diving suit: Made of leather with cane tubing leading up to a diving bell on the surface; and using a balloon which could be inflated and deflated at will this is the forerunner of scuba gear. Again it was intended for use in war - sneaking up on enemy ships and making holes in them from below.
4. A self propelled cart, thought to be designed for the theatre, it was powered by coiled springs, and could be programmed to move in pre-set directions. It was a type of robot and could be seen as the very first car. Scientists in Italy built one in 2006 from da Vinci's designs and found that not only did it work, it looked a bit like the Mars Rover.
5. The humble ball bearing is another invention of his. It may not seem as impressive as flying machines and diving suits, but da Vinci realised that using a spherical bearing in devices with moving parts made them much more efficient by removing friction. It was such a fundamental idea that it is still used widely today.
6. City design - after Milan was devastated by an outbreak of plague, da Vinci set about designing a city that would limit the spread of disease. Wider streets, so people weren't jammed together, air vents in buildings and a sanitation system would have helped achieve this. The buildings themselves would have been beautiful - da Vinci's artistic soul wanted everything on the surface of the city to be pleasing to the eye. It was never built, though.
7. Robotic knight: designed for a pageant rather than as a fighting machine, an elaborate humanoid figure with gears and pulleys and wheels that would allow it to sit down, stand up and move its head.
8. Movable bridges - for troops on the move, allowing them to cross rivers more easily.
9. Viola Organista a type of stringed musical instrument played by pressing keys, similar to a hurdy gurdy
10. Anenometer - an instrument for measuring wind speed.