16 Cook Street (1866), both built in Liverpool, England, by local architect and civil engineer Peter Ellis, are characterised by their extensive use of glass in their facades. Towards the courtyards they even boasted metal-framed glass curtain walls, which makes them two of the world's first buildings to include this architectural feature. The extensive glass walls allowed light to penetrate further into the building, utilizing more floor space and reducing lighting costs. Oriel Chambers comprises set over five floors without an elevator, which had only recently been invented and was not yet widespread. The Statue of Liberty (1886) features a thin, non-load-bearing copper skin. An early example of an all-steel curtain wall used in the classical style is the department store on , Berlin, built in 1901 (since demolished). Some of the first curtain walls were made with steel mullions, and the polished plate glass was attached to the mullions with asbestos- or fiberglass-modified glazing compound. Eventually silicone sealants or glazing tape were substituted for the glazing compound. Some designs included an outer cap to hold the glass in place and to protect the integrity of the seals. The first curtain wall installed in New York City, in the United Nations Secretariat Building (Skidmore, Owings, and Merrill, 1952), was this type of construction. Earlier modernist examples are the Bauhaus in Dessau (1926) and the Hallidie Building in San Francisco (1918). Ludwig Mies van der Rohe's curtain wall is one of the most important aspect of his architectural design. Mies first began prototyping the curtain wall in his high-rise residential building designs along Chicago's lakeshore, achieving the look of a curtain wall at 860-880 Lake Shore Drive Apartments. He finally perfected the curtain wall at 900–910 Lake Shore Drive, where the curtain is an autonomous aluminum and glass skin. After 900–910, Mies' curtain wall appeared on all of his subsequent high-rise building designs including the Seagram Building in New York. During the 1970s, the widespread use of aluminium extrusions for mullions began. Aluminum alloys offer the unique advantage of being able to be easily extruded into nearly any shape required for design and aesthetic purposes. Today, the design complexity and shapes available are nearly limitless. Custom shapes can be designed and manufactured with relative ease. The Omni San Diego Hotel curtain wall in California, designed by architectural firm Hornberger and Worstel and developed by JMI Realty, is an example of a