Chatham Lighthouse,known as Twin Lights prior to 1923, is a lighthouse in Chatham, Massachusetts, near the “elbow” of Cape Cod. The station was established in 1808, the second light on Cape Cod. To distinguish it from Highland Light, the first Cape Cod light, and to act as a range, twin octagonal 40-foot (12 m) wooden towers were built. They were on skids so that they could be moved to keep them in line with the entrance channel as it shifted. The current structures were built in 1879 of brick lined cast iron with a Fourth Order Fresnel Lens. Today, the former keeper’s house is an active U.S. Coast Guard station, and on-duty personnel living quarters. Quick pencil sketch with Koh-I-nor solid graphite 4B pencil in the Alpha Series Stillman and Birn.