Mark Twain once went to borrow a certain book from a neighbour in Tarry town."May I borrow a book from you?" he asked politely."Yes, you're more than welcome to it," the neighbour told him."But I must ask you to read it here. You know I make a rule never to let any book go out of my library."Some days later the neighbour wished to borrow Twain's machine for cutting grass in the garden."Why, certainly," Twain told him, "You're more than welcome to it. But I must ask you to use it here. You know that I make it a rule never to let it go out of my garden."