of the media. It also maximizes natural light and the physical transparency of the facade. The window panes are generally protected by the ceramic rods. Since the rods contain a small gap at each story, the glass panels contain a small ceramic frit near these gaps. At ground level, there are glass storefronts, which allows pedestrians outside to see into the lobby. The notched corners contain exposed steel and lack screens, a design feature that represents the ideal of journalistic transparency. Instead, the corners contain one- and two-story-high rods, which serve as bracing and are designed in a pattern resembling the letter "X" (see ). Structural features Substructure Underneath the site is durable Hartland bedrock. Before the tower was constructed, the contractors made three sets of borings to extract samples of the composition of the ground. Directly underneath the tower portion of the site, the samples generally contained poor-quality weathered and decomposed rock at a depth of up to . The borings on other parts of the site and underneath the surrounding sidewalk generally contained competent rock at a shallow depth, which increased in quality at greater depths. Furthermore, the northern lot line is adjacent to the IRT Flushing Line subway tunnel (used by the ) below 41st Street, as well as a pedestrian passageway at a shallower level. The western lot line is adjacent to the IND Eighth Avenue Line subway tunnel (used by the ) under Eighth Avenue. The foundation had to be capable of supporting of pressure. Most of the foundation is on intermediate- or high-quality rock and uses spread footings capable of . Caissons with rock sockets are installed under the southeast corner of the tower section, where the weakest rock exists. There are forty-two caissons with a diameter of , which extend between deep. They are reinforced with steel bars and could hold of vertical pressure. They are filled with concrete with a compressive strength of . Superstructure The building contains a superstructure with of steel. More than 95 percent of the beams are made of recycled steel. Steel was chosen over concrete because it allows flexible office spaces. The superstructure contains box columns measuring in diameter. The flanges range from thick at the base to thick at the top stories, giving a lighter appearance. The beams are covered with intumescent coatings for fireproofing. The floor slabs are a composite consisting of of concrete on