ABSTRACT
Contrary to the theories of Hooke ( 1665) and de Luynes ( 1875), it is now accepted that the surface of a Rupert's drop is in compression and the central zone in tension. However, it is not yet clear who first proposed this state of stress in a Rupert's drop. It appears that the stress distribution even in a block of thermally tempered glass was not clearly understood until the early part of the 20th century (see de Fremin ville (1914 ), Littleton and Preston (1929)). It seems, therefore, that once the stresses in tempered glass were understood, and because the process of formation of a Rupert's drop has many similarities with the tempering process, it became quite straightforward to assume a qualitative similarity of the compressive and tensile stresses in the Rupert's drop and in a block of thermally tempered glass.
