|Braun has had difficulties with the air pump over the past few months, which he had not expected. He has obtained two preliminary results of D=5.530 but he is unhappy about their exactness. He feels ill at the moment but will continue when he is in better health. Even with these two results, the result of 5.527 [density of the Earth] will not require much alteration. He aspires to a vacuum of 0.2mm at which he will obtain a proof of the elasticity of the quartz fibre.