"Do you know it is three miles to the cape?"
"Yes, it is approximately that distance. I measured it by triangulation some time ago, using our house and Observation Hill as the base line."
The boys had neglected to take this precaution.
"What was your object in doing that?"
"So that we might have some means to observe the speed our boat could make. If we knew the speed of the wind, we might be able to calculate our distance."
"But the wind has been coming from the north and we are sailing due west. Would not the difference in the speed of the wind make a difference in the speed of the boat?"
"It was for that reason I stated if our rate of travel was the same we would have made that distance. The wind has been variable at different points along the coast, so that our average may have been four miles per hour."
"At what speed has the wind been during the day; I mean the average speed?"
"Less than eight miles an hour?"
"If the wind had been coming from the east we could have made much better time, and we might then have been near the mouth of the West River," was Harry's conclusion.