The art of lens grinding
Working Principle of the exhibit
Historical Background: In the early seventeenth century, exploitation of telescope in observational astronomy gave lens making ever greater importance among amateurs and scholars. Early astronomical lenses were produced by the mirror makers in Murano and Venice in air lathe.
Ippilito Francini converted air lathe into optico lathe. Francini produced most of the lenses for Galileo during 1623-1642 under Galileo’s personal supervision.
Working Principle: A disk known as blank was cut from glass (made off soda-lime and silica). The craftsman turned the flywheel with his right hand and held the glass blank with the left hand against the turning mould to get the desired curvature. A mixture of resin, finely ground clay, pulverized glass was used as abrasives for lens grinding and polishing. However, the accuracy of the final product was depended on the skill of the artisan.
Mode of display:
This lathe is the exact replica of Francini Lathe, which is kept at Museo Galileo. Based on the original lathe, a full scale 3D drawing has been done and then the replica has been reproduced with each and every detail.