The construction of a low friction, air supported pulley for use in floating wire measurements and the methods used to test its performance are described. The quality of the results obtainable in floating wire measurements with such an air bearing is illustrated by several measurements performed on a 100 cm radius, 180°, double‐focusing magnetic analyser at the Rutherford High Energy Laboratory. The use of bearings of this type as pivots for bullion balances, and the possibility of employing such a modified bullion balance to measure the Newtonian constant of gravitationGto increased accuracy are considered.