"We'll take soundings," said Alec. "We'll make a few turns right across one end of the bed, then try it lengthwise. We want to make a very thorough study of these grounds, for if Captain Hardy didn't steal his oysters, then he's got a very good bed."
From the cabin Alec brought a big sheet of paper, which he fastened to the cabin-top. On it he marked the positions of the four corner stakes. "This will give us plenty of room to make notes on," he said. "Later we can copy what we like on the map of the beds. I'll just put down the date and the state of the tide and the weather." He wrote on the paper and handed his pencil to Elsa. "I'll sound if you'll make the entries," he suggested.
"I can steer, too," said Elsa. She took the paper and sat down by the tiller.
Alec closed the throttle of the engine. The Osprey at once dropped to very low speed. Alec got his line ready, and lowered it. "Fifteen feet," he called. Elsa entered the figures on the temporary chart. A few fathoms away he cast the lead again. "Fourteen feet, nine inches," he called. A few rods farther along the line registered fifteen feet, one inch. So it went straight across the bed, the bottom being practically level.
"I'll make one more cast," said Alec. "Then you swing her to port and we'll cut right back across the bed again."
The Osprey was almost at the outer boundary of the grounds. Alec dropped his lead. "Hello!" he cried in surprise, as he watched the line. "Got eighteen feet here! That's funny. Just keep her straight for a few rods. I want to see how wide this hole is." The depth continued constant at eighteen feet. "That's queer," commented Alec. "Bring her about. We'll see how it is a few fathoms farther down-stream."
Elsa brought the Osprey about as directed. "Still eighteen feet," said Alec, sounding repeatedly. They came to the boundary of Hardy's bed. "Eighteen feet," called Alec. Before Elsa could get it written down, he called again, "Fifteen feet." And eighteen feet it continued all the way across the bed.
Once more they came about and crossed the bed still farther down-stream. Again the lead showed fifteen feet, almost to the edge of the bed, when the line suddenly paid out an additional three feet.
"We'll just cover the entire bed this way," said Alec, "instead of running lengthwise as we had planned. It looks to me as though there is a regular trough in the bottom, running right along the edge of this bed. I'd like to know how wide and how long it is. I wonder what ever could have scooped out such a furrow in the mud."
They kept on, crossing and recrossing the oyster-bed, until they had sounded it from end to end. And at every trip across the bed they got practically the same figures—fifteen feet in Captain Hardy's grounds and eighteen along the edge.