Charles Greeley Abbot (May 31, 1872 – December 17, 1973) was an American astrophysicist and the fifth secretary of the Smithsonian Institution, serving from 1928 until 1944. Abbot went from being director of the Smithsonian Astrophysical Observatory, to becoming Assistant Secretary, and then Secretary of the Smithsonian Institution over the course of his career. As an astrophysicist, he researched the solar constant, research that led him to invent the solar cooker, solar boiler, solar still, and other patented solar energy inventions. Early life and education Charles Greeley Abbot was born in Wilton, New Hampshire. His parents, Harris Abbot and Caroline Ann Greeley, were farmers and he was the youngest of four children. As a youth he built and invented numerous things, such as a forge to fix tools, a water wheel to power a saw, and a bicycle. He dropped out of school when he was 13 to become a carpenter. Two years later he went back to high school. He attended Phillips Academy. When a friend of his went to Boston to take the entrance exam to get into the Massachusetts Institute of Technology, Abbot went for the chance to visit Boston. However, upon arrival, he was uncomfortable visiting Boston alone and chose to take the exam instead. He passed and his family gathered the funds to send him to MIT for one year. He started out studying chemical engineering, but eventually moved on to physics. He graduated in 1894 with a Master of Science in physics. During his time in Boston, Abbot met Samuel P. Langley on the MIT campus when Langley visited seeking an assistant. In 1895, he would start working as an aid at the Smithsonian Astrophysical Observatory. Smithsonian Astrophysical Observatory While at the Smithsonian Astrophysical Observatory (SAO), Abbot would work under Samuel P. Langley. Langley would go on to change his focus from solar radiation to aeronautics, with Abbot taking over solar radiation research. Abbot would participate in many expeditions. In 1900 he, along with Langley, would travel to Wadesboro, North Carolina to observe a solar eclipse, followed by another eclipse expedition to Sumatra in 1901. During his expedition experiences he would also travel to Algeria, Egypt, South Africa, Australia, and other countries, often in partnership with the National Geographic Society. Abbot would become acting director of SAO in 1906 and in 1907, Abbot became the Director of the Smithsonian Astrophysical Observatory, following the death