What queer things you do tell me! How can that be?
You know that the world attracts you.
Yes; I know when I jump up I am soon brought down, and sometimes unpleasantly so, too.
As the world is round, and everywhere the world pulls things down to its surface, it is as if it were drawing all to the centre. This is called the Attraction of Gravitation.
And I suppose that like as fire is hotter the nearer you get to it, so does the attraction get greater the nearer you get to the centre of the earth.
True; but can you guess how this gravitation can be weight?
I know when I pull a thing, it is as if I pushed it, or put a weight on it. So the pulling of the earth will make the thing attracted feel as if a weight were on it.
And can you not see why a pound should somewhere not be a pound?
No; unless I made a big hole towards the centre, and then the pound weight would be heavier. But you told me the world was round, and it must be as far from the centre at London and Melbourne, as at the equator.
But if from trial it be found that the pound really is less at the Line, what would it prove?