Letter from Carl Braun, Mariaschein, Bohemia, to Charles Vernon Boys Finally, he has managed to place a quartz fibre in the torsion balance without it breaking under testing. The fibre has carried the lever for seven days now. He cannot think of a reason for the feebleness of the fibres other than perhaps an impurity. Braun should begin observations in about three weeks. He gives preliminary calculations for the present arrangement of equipment. 30 March 1900