Of skeleton keys there is a very admirable selection at New Scotland Yard. They are made both of iron and steel--mostly of scrap-iron, as it is tougher and has no grain in it. Burglars and housebreakers usually make their own skeleton keys--some of which are very rough. The key is bought in the block, and the wards are cut out as needed. Those shown are of two kinds. The bunch consists of "pick-locks," which are made of stout wire. A housebreaker has been caught with as many as thirty of these pick-locks in his possession. For larger locks, the keys are much stronger. This pretty little cloth case was found on a gentleman. These would be used for opening heavy doors. Of those shown it will be noticed that all save two are made with the wards to both ends. There can be no doubt as to the efficacy of skeleton keys, and lever locks are strongly recommended to the wise, as it would be impossible to open one with a "skeleton." [Illustration: SKELETON KEYS.] We now come to the wedges--apparently very small, but incalculably important items in the particular branch of art with which we are now dealing. Wedges may be either of wood or steel, and are used for driving under doors whilst working in a room. They are usually held tight to the floor by a gimlet, so that if the housebreakers were disturbed and an attempt was made to open the door, the more the opposing party was to push outside, the tighter the door would be held. The only hope would be to force the door and the thieves in nine cases out of ten would have ample opportunity to get away.