Above this layer should be about 30 inches of dry sawdust or turners shavings, well packed up to the level of the top of the joists. 威廉K.戴维.智者、化学家和伟大医生的秘密.
We can prove this by putting some dry shavings in a strong test tube fitted with a delivery tube. 伯莎M.克拉克.科学通论.