"Just what are you aiming to do?" asked Mr. Damon.
"See how far each one of those weighted objects drifts," Tom replied. "We have planted them in different spots on the ocean bed. Some will drift farther than others. Some are large and some are small. By striking an average we may be able to tell about how far from the supposed location of the Pandora we ought to look for her."
The night passed without incident and as calmly and peacefully as though they were all in some deep cave beneath a great mountain. In the morning after breakfast Tom and his friends went outside the submarine again and noted the weighted objects. Some had drifted farther than others. Measurements were carefully taken, and then began a series of intricate calculations.
The distance each object had drifted from the iron bar marker was considered in reference to its size and shape. Also the elapsed time was computed. The results were then compared, an average struck, and then the size and weight of the Pandora, as nearly as they could be ascertained, were figured. The resultant figures were compared, and Tom announced:
"If we are anywhere near right in our conclusions we ought to begin to search for the treasure-ship about four miles from here, in a general northerly direction."
"Do you think she has drifted that far?" asked Ned.
"Fully that," Tom answered. "That is only our starting point—the center of a new series of circles."
A moment later Tom gave the order to rise to the surface.
"Going up?" exclaimed Ned.
"Yes, I want to make some observations to determine our exact nautical position."