In crystallography, a disclination is a line defect in which there is compensation of an angular gap. They were first discussed by Vito Volterra in 1907, who have an analysis of the elastic strains of a wedge disclination. By analogy to dislocations in crystals, the term, disinclination, was first used by Frederick Charles Frank and since then has been modified to its current usage, disclination. They have since been analyzed in some detail particularly by Roland deWit.