clean down उदाहरण वाक्य

The impressions taken on the steep outside slope of the reef were marked with the shapes of living corals, and otherwise were clean down to about 10 fathoms ( 18 m ); then at increasing depths, the tallow showed fewer such impressions and collected more grains of sand until it was evident that there were no living corals below about 20 30 fathoms ( 36 55 m ).