This machine cuts the threads of screws
A bar, the one to have the thread cut into it, would be laid in between the two screws.
As the cranks on the end of the table were turned, the cutting blade would be carried down the two screws, creating an even groove to be used for screws, bolts, etc.
He recorded in his notebooks the records of model sittings; but records of the Mona Lisa model sitting are nowhere to be found
Theories are that Leonardo painted himself, and this theory is supported by analyzing the facial features of Leonardo’s face and that of the famous painting
If the features of the face were placed on top of each other, and flipped, they would align perfectly
Leonardo wrote in Italian using a special kind of shorthand that he invented himself
He usually used “mirror writing,” starting at the right side of the page and moving to the left
Only when he was writing something intended for other people did he write in the normal direction
Leonardo’s Signature in a notebook www.mos.org/sln/Leonardo/write.html