Cumulus is comprised of glass vessels that have been sandblasted to a milky translucent finish. Their surfaces suggest the slow process of erosion, accelerated here by the use of modern technology. Each level of vases, bottles and bowls appears to support the glass shelf above. In fact, the shelves are supported by square glass bricks that form the central core of the sculpture.Cumulus is an ‘accumulation’, a word describing much of Cragg's sculptural practice. He is known for collecting and arranging found objects, with references to geology and archaeology, past and present, nature and culture.