Hydraulic Millstone?

Xue Sifu laughed. 

"A few dozen would be more than enough. A few dozen pieces is equivalent to a few dozen bowls. Originally, the highest number of bowls we sold in a day was about hundred and sixty bowls of rice noodles. We're not only selling liangpi, we're also selling rice noodles.

"Well it's also because my stall is small. Besides, there isn't a tree beside my stall for shade and it hasn't been windy. Once it gets hot, no one would want to sit in the heat. Even if I build a sunshade, it'll be useless. 

"I only managed to sell a hundred and sixty bowls a few days ago. These two days, I barely reached a hundred. Many people would rather eat in a cooler place. for example, there's a noodle stall on the same street. It's in a very good location and is under a very large tree. The whole stall is covered by the tree's shade.