The device was never studied or used as a filter by either Lagrange or later investigators such as Charles Godfrey .
Joseph - Louis Lagrange ( 1736 -- 1813 ) studied waves on a string periodically loaded with weights .
The device was never studied or used as a filter by either Joseph - Louis Lagrange or later investigators such as Charles Godfrey .
Joseph - Louis Lagrange ( 1736 -- 1813 ) studied waves on a string periodically loaded with weights .