“Very likely,” replied Jack, “that is a sine that he don’t like it.”

“You have not yet entered into acute trigonometry?”

“Not come to that yet,” replied Jack.

“That will require very sharp attention.”

“I should think so,” replied Jack.

“You will then find out how your parallels of longitude and latitude meet.”

“Two parallel lines, if continued to infinity, will never meet,” replied Jack.

“I beg your pardon,” said the gunner.

“I beg yours,” said Jack.

Whereupon Mr Tallboys brought up a small map of the world, and showed Jack that all the parallels of latitude met at a point at the top and bottom.