This is the class of men who are the greatest trouble to the police--these are the best customers of the receivers. Frequently a man is employed to do all the planning and mapping out for the party who will do the actual job. For this he is paid a certain price or perhaps a commission on the results of the robbery. This person will draw up a plan of the house as true--though perhaps not quite as artistic--as any architect. But he gives the thief the very information he needs, and puts on the map of the house and grounds the exact position where the operator must "beware of the dog." A man named Connor is credited at New Scotland Yard with being one of the finest adepts at this particular work of all which have come under their notice. He used to lecture on this peculiar art to young thieves, and whilst in prison wrote a work giving them practical advice on the subject. The prison officials allowed him to finish his literary effort, and when his time expired coolly appropriated the same. [Illustration: PEACE'S CRUCIBLE.] No article dealing even in a small way with "Burglars and Burgling" would be complete without some reference to "The King," and the relics of this talented individual are of a highly interesting character. Charles Peace thoroughly deserved to be crowned king of all burglars, housebreakers, and scoundrels in general. Peace always worked single-handed. He had no "receiver," and melted down all his own stuff and sold it as a matter of business. All his stock-in-trade is to be found at the museum. His tools are only ten in number, and comprise a skeleton key, two pick-locks, a centre-bit, a large gimlet, a gouge, a chisel, a small vice (for turning keys on the outside of doors--used when people leave the key in the lock), a jemmy (about 2ft. long), and a knife. With these Peace worked. His blue spectacles and case are not missing. These he used for purposes of disguise, though when arrested at Blackheath his face was stained with walnut-juice, in the hopes of passing off as a Mulatto. His ladder was quite a unique arrangement. When doubled up it is to all outward appearances simply a bundle of blocks of wood such as any carpenter might carry home for firewood. But it opens out to a length of some 13ft., working on a bolt, with a hole at one end to hook on to a nail in the wall, and so complete facilities were afforded for climbing to window or veranda. In addition to his tools he called into requisition a pony and trap at night. He practically killed the pony with hard work.