Charles Greeley Abbot was born at Wilton, New Hampshire, USA on May 31, 1872. Abbot was somewhat different from the other astronomers on this site because his work involved more than the study of the Sun.

Dr. Abbot's Sun work was mostly concerned with understanding sunspots and the ebb and flow of radiation that reaches the Earth. He studied the sun's radiation, how it varies, how much there is of it, and how it changes when it enters Earth's atmosphere.

Abbot sought clear skies for his observations, and set out to find them in California. With these improved atmospheric conditions he was able to prove that the methods of measurement he had perfected were not effected by the altitude at which the observations were made. With the bolometer he studied the heating effect of the solar corona. And he was successful in measuring the solar radiation. He found evidence of its variability. By taking measurements at four different geographic locations and altitudes he proved that the solar radiation varies irregularly.

He also discovered that the Sun is a variable star and that it does not have a steady output of heat. With his radiometer he made considerable progress in measuring the heat in the spectrum of the brighter stars. He felt that the changes in Earth's weather must depend at least partly on the sun's variations. His view found new support in evidence produced by a new system he devised for measuring and recording the changes in the energy reaching the earth from the Sun. This was of special interest because of how it applied to agriculture, long-distance weather forecasts and Earth's magnetism.

Abbot worked for most of his life measuring and recording the effect of solar radiation on yearly weather patterns as well as how solar radiation influences life on Earth through the process of photosynthesis. In 1929 he established the Division of Radiation and Organisms, which later became the Smithsonian Radiation Biological Laboratory. He strongly believed that there was a relationship between fluctuations in solar radiation and climate patterns and attempted to predict the weather. He was criticized a great deal in this regard.

In 1907, Abbot was appointed director of the SAO, and, in 1928, upon the death of Charles Doolittle Walcott, he became the fifth Secretary of the Smithsonian Institution. While Secretary he had to work to correct the incorrect measurement of the solar constant that had been taken by Langley and his associates. When he was working at the SAO, he had worked on Langley's bolometer and galvanometer; and had improved the accuracy of both instruments and was able to correct the measurements of the solar constant which had been done incorrectly before.

While Secretary of the Smithsonian he had quite a controversy on his hands. Before he became Secretary the Institution was already involved in a dispute with the surviving Wright brother, Orville over who had the first flying machine. Abbot disagreed with the standing position of the Smithsonian, that the Langley flying machine, the Aerodrome, had been the first, and he disagreed with the way the Institution had handled the entire situation. Abbot thought his friend and mentor had not completely studied the necessary details before attempting the flights; this in turn led to the repeated failures.

The situation had reached the point where Orville refused to let the Smithsonian have his original 1903 "Flyer" and instead had it displayed in London. Abbot tried to resolve the strife by meeting with Orville but nothing was really accomplished until 1942 when things were settled and Wright and Abbot shook hands after Abbot gave a report listing 35 differences between the Aerodrome and the Flyer.

Charles Greeley Abbot, fifth Secretary of the Smithsonian, died in Maryland at the age of 101.

    

©Copyright 1998 Elizabeth Beckett, Holly Bernitt, and Vishwa Chandra.