Galileo's objective lens
Galileo's objective lens is a specific objective lens held in the Museo Galileo, Florence, Italy. It was used by Galileo Galilei in the Galilean telescope with which he discovered the four largest moons of Jupiter in 1610. The lens has a diameter of 38mm and a gilt brass housing. The frame is made of ebony and ivory and has dimensions of 410mm x 300mm.