In 1881, the firm was commissioned to build the Montauk Building which would be the tallest building in Chicago at the time. To solve the problem of the city's water-saturated sandy soil and bedrock below the surface, Root came up with a plan to dig down to a "hardpan" layer of clay on which was laid a thick pad of concrete overlaid with steel rails placed at right-angles to form a lattice "grill", which was then filled with Portland cement. This "floating foundation" was, in effect, artificially-created bedrock on which the building could be constructed. The completed building was so tall compared to existing buildings that it defied easy description, and the name "skyscraper" was coined to describe it. Thomas Talmadge, an architect and architectural critic said of the building, "What Chartres was to the Gothic cathedral, the Montauk Block was to the high commercial building."