"That is just what the Post-Office people said," replied George, "but it is quite wrong. If you look at this sketch that I have just made, you will see that there is no difference whatever. If the posts are a hundred yards apart, just the same number will be required on the level as over the surface of the hill."
"Surely you must be wrong, George," said Mrs. Allgood, "for if the posts are a hundred yards apart and it is half a mile farther over the hill, you have to put up posts on that extra half-mile."
"Look at the diagram, mother. You will see that the distance from post to post is not the distance from base to base measured along the ground. I am just the same distance from you if I stand on this spot on the carpet or stand immediately above it on the chair."
But Mrs. Allgood was not convinced.
Mr. Smoothly, the curate, at the end of the table, said at this point that he had a little question to ask.
"Suppose the earth were a perfect sphere with a smooth surface, and a girdle of steel were placed round the Equator so that it touched at every point."
"'I'll put a girdle round about the earth in forty minutes,'" muttered George, quoting the words of Puck in A Midsummer Night's Dream.
"Now, if six yards were added to the length of the girdle, what would then be the distance between the girdle and the earth, supposing that distance to be equal all round?"
"In such a great length," said Mr. Allgood, "I do not suppose the distance would be worth mentioning."