The workmen all stand on high benches, up from the floor, and under the hogs we find troughs to keep any scraps from getting under the workmen’s feet. 佚名.神奇的知识之书.
These troughs reach over to the center of the top of the joists, and are soldered together, so that no water will drip on the floor below. 威廉K.戴维.智者、化学家和伟大医生的秘密.
In using the method for saw blades, they are first heated in a suitable furnace and then placed vertically, teeth upward, in troughs filled with the mixture. 威廉K.戴维.智者、化学家和伟大医生的秘密.
The windmill pumps water into the troughs where cattle drink. 伯莎M.克拉克.科学通论.