He ran back with the spring he had bought, and very soon had the lock to pieces, and was busy cleaning the different parts of it. This sort of work he had often done for his father, and he did not mind the trouble of rubbing, and scrubbing, and scraping that was required to remove the rust. It took him a long time to clean the old thing thoroughly, and make it serviceable again; but the lock was a good one and worth the trouble, and when at last Jack had got it all fitted together again, he was delighted to find that it would work as easily as possible.