The history of the 125 year old Eotvos torsion balance

The paper is a comprehensive history of Eotvos' torsion balance from the initial experiments of its inventor to the final stages of torsion balance development. It gives a review of the characteristics of the successive types of the instrument and the main features of their development. It covers briefly the contribution of Ferdinand Suss the constructor of the instruments whose mechanical expertise contributed to the success of the torsion balances to a great extent. It appreciates the activity of Hugo Bockh, a well-known Hungarian geologist, who recognised the geological aspects of torsion balance surveys in an early period and initiated their introduction to oil prospecting.