"Aunt Polly's awful par- ticular about this fence. There ain't one boy in a thousand - maybe a hun'red thousand - can do it the way it's got to be done!" - "Lemme try! Say - I'll give you the core of my apple!" - - and Tom has discovered a great law of human nature; namely, in order to make a man or a boy covet a thing, it is only necessary to make it difficult to attain!