Mona Lisa's Shadows

Photo of people taking photos of the Mona Lisa courtesy 123rf.com

Leonardo da Vinci used 30 layers of paint, about 40 micrometers each, on the Mona Lisa in order to execute a technique called Sfumato, which makes shadows look realistic.  For more information click here.  What did you learn today?

Leonardo da Vinci's First Flying Machine

Photo of reconstruction of one of Leonardo da Vinci's flying devices courtesy www.leonardo3.net

On this day in 1496 Leonardo da Vinci (1452-1519) made his first attempt to launch a flying machine.  It was not successful, so he worked on the invention for several more years before he attempted another launch.  His first flying devices were based on the structure of birds' wings and bats' wings.  He also developed an idea for a helicopter-type device.  Click here to view reconstructions of several of his ideas for flying devices.

Leonardo da Vinci is one of history's most interesting persons for me.  I've read several biographies, and enjoy his paintings.  Who is one of your favorite historical persons and why?

Earliest Mechanical Calculator

Photo courtesy FreeImagesLive

The earliest attempt at designing a mechanical adding machine was probably by Leonardo da Vinci (1452-1519), according to some of his notes found in 1967 in the National Museum of Spain.  The next two documented attempts were by the German Wilhelm Schickard (1592-1635) in 1623.  The location or existence of the two prototypes are unknown.

In 1642, the 18 year old Frenchman, Blaise Pascal (1623-1662), invented the first "arithmetical machine", and subsequently developed it further.  About 50 of these machines still exist.