An important contribution Greenhill made to the theory of elasticity was his study of the greatest length that a cylinder can have before it bends under its own weight.
Isang mahalagang kontribusyon Greenhill ginawa sa teorya ng pagkalastiko ay kanyang pag-aaral ng pinakamataas na haba na ang isang silindro ay maaaring magkaroon ng bago ito bends sa ilalim ng kanyang sariling timbang.