1872 – Born on the 31st of May in Wilton, New Hampshire.
1894 – He graduated from Massachusetts Institute Of Technology located in Cambridge, Massachusetts.
1895 – He was hired because of his skill at laboratory work, despite his lack of experience in astronomy.
1896 – He became acting director of the Smithsonian Astrophysical Observatory when Langley died.
1900 – He designed and built devices for measuring solar radiation, including a greatly improved
Bolometer which measured the Sun’s inner corona at the solar eclipse in Wadesboro, North Carolina.
1907 – He succeed as a director, and Charles Walcott became Smithsonian secretary.
1910 – He won the Henry Draper Medal of the National Academy of Science.
1915 – He won the Rumford Prize of the American Academy of Arts and Sciences.
1918 – He became Assistant Secretary of the Smithsonian Institute.
1928 – He was a secretary of the Smithsonian Institution.
– He succeeded Walcott as Secretary and guided the Institute through the turbulent years of the
Great Depression and World War II.
1938 – He authored perhaps his most singular study, although anonymously and this was his contribution
to the Journal of Parapsychology detailing his studies into clairvoyance.
1944 – He retired as both Smithsonian Astrophysical Observatory director and Smithsonian Secretary ,
being the first Smithsonian Secretary not to die in office.
– He delegated the National Museum largely to his Assistant Secretary, Alexander Wetmore who
succeeded him as Secretary.
1949 – He published a replication of his findings, this time under his own name, in the Journal.
1973 – He obtained his last patent at the age of 101, the oldest inventor to ever receive a patent.
– He died on the 17th of December in Washington.