critical to the recording process, and fresh tanks were delivered weekly. The Grateful Dead and their engineer, Dan Healy, reportedly made use of this feature. Al Kooper wrote that during the few days that he was helping Lofgren lay down tracks for Cry Tough, Kooper was so taken with the novel drug experience that he wheeled one of the tanks around and kept it next to him for refreshment between takes. He breathed in so much of it that acid collected in his stomach, aggravating his ulcers, and for a few days he was too sick to work. Kooper said that the studio's fun with nitrous oxide was stopped forever when a friend of Kellgren was found dead from asphyxia under one of the tanks, the tube still in his mouth. The Pit To satisfy the wishes of Sly Stone, one of the office spaces at the studio was turned into an unusual recording studio dubbed "the Pit". The Pit was a acoustically dead room that had the engineer's controls sunk into the foundation of the building, surrounded on all sides by a ground level area intended for the musicians. Its appearance was futuristic, with bright maroon plush carpet on the floors, walls, ceiling and stairs. Psychedelic murals and embroidery added to the visual atmosphere. There were no windows between the control room and the main studio area, previously considered a fundamental method of sound separation; instead, there was a partial cowling circling the control pit, also carpeted. A bunk bed was accessible from the perimeter of the Pit, reached only by climbing through a giant pair of red lips. At the head of the bed, audio jacks allowed for microphones to be connected to the console in the Pit so that an artist could vocalize from under the covers. Guitarist Bob Welch wrote that "it really was the height of '70s 'over-the-top-ness'." Al Kooper said "it looked like something out of Thunderdome." Jack Bruce thought it was decorated to look like a human heart, "with all kinds of red, synthetic fur on the walls." Stone recorded in it from time to time, but mostly it remained an unused curiosity, a "white elephant" according to producer Jimmy Robinson, a room that new arrivals were shown to elicit an "oh wow, what a trip" response. The separation between engineer and musician frustrated Stone and he recorded as much as possible down