He now seated me near the machine, so that it was on my right, and turned a switch somewhere below the crowning duster of glass bulbs. The usual sputtering began, turned to a whine, and terminated in a drone so soft as to suggest a return to silence. Meanwhile the luminosity increased, waned again, then assumed a pale, outré color or blend of colors which I could neither place nor describe. Tillinghast had been watching me, and noted my puzzled expression.