Holmes Castle included soundproof sleeping chambers with peepholes, asbestos-padded walls, gas pipes, sliding walls, and vents that Holmes controlled from another room. Many of the rooms had low ceilings and trapdoors in the floors, with ladders leading to smaller rooms below. The building had secret passages, false floors, rooms with torture equipment, and a specially equipped surgery. There were also greased chutes that emptied into a two-level cellar, in which Holmes had installed a large furnace. There was even an asbestos-lined chamber with gas pipes and evidence of something having been burned inside. It was believed that Holmes placed his chosen victims into the special chambers into which he then pumped lethal gas, controlled from his own bedroom, and then watched them react. Apparently, he gained some fiendish pleasure from this activity. Sometimes he'd ignite the gas to incinerate them, or perhaps even place them on the elasticity determinator, an elongated bed with straps, to see how far the human body could be stretched. When finished, he might have slid the corpses down the chutes into his cellar, where vats of acid and other chemicals awaited them.