One proposal called for 180,000 tons of molten wax (or alternatively, Vaseline) to be pumped into Titanic, lifting her to the surface.[12] Another proposal involved filling Titanic with ping-pong balls, but overlooked the fact that the balls would be crushed by the pressure long before reaching the depth of the wreck.[13] A similar idea involving the use of Benthos glass spheres, which could survive the pressure, was scuppered when the cost of the number of spheres required was put at over $238 million.[12] An unemployed haulage contractor from Walsall named Arthur Hickey proposed to encase Titanic inside an iceberg, freezing the water around the wreck in a buoyant jacket of ice. The ice, being less dense than liquid water, would float to the surface and could be towed to shore. The BOC Group calculated that this would require half a million tons of liquid nitrogen to be pumped down to the sea bed.[14] In his 1976 thriller Raise the Titanic!, author Clive Cussler's hero Dirk Pitt repairs the holes in Titanic's hull, pumps it full of compressed air and succeeds in making it "leap out of the waves like a modern submarine blowing its ballast tanks", a scene depicted on the posters of the subsequent film of the book.