“At the latitude of Iceland, where we now are, the radius of the earth, the distance from the centre to the surface is about 1,583 leagues; let us say in round numbers 1,600 leagues, or 4,800 miles. Out of 1,600 leagues we have gone twelve!”

“So you say.”

“And these twelve at a cost of 85 leagues diagonally?”

“Exactly so.”

“In twenty days?”

“Yes.”

“Now, sixteen leagues are the hundredth part of the earth’s radius. At this rate we shall be two thousand days, or nearly five years and a half, in getting to the centre.”