Commission 38 (Exchange of astronomers) and Commission 46 (Teaching of astronomy): two commissions that played a unique role in the history and development of the IAU

The founding and development of two commissions of the IAU that played a unique role in IAU history are traced. Commission 38 for the Exchange of astronomers was founded in 1946 with Frederick Stratton as first president, and it expended funds (initially granted by UNESCO) for astronomers to travel on exchange visits. Commission 46 for the Teaching of astronomy was founded in 1964 with Evry Schatzmann as first president. This was a time of rapidly growing interest in the IAU for teaching astronomy and in due course for promoting astronomy in developing countries. For a while, both commissions operated under the wing of the Executive Committee. Their role was unique as they were the only IAU commissions to have their own budget, as well as aspiring to bring about social change in the astronomical community. By 2000 both commissions merged into C46 (Astronomy education and development) and by that time various programmes such as the International School for Young Astronomers (ISYA), the working group World-wide Development of Astronomy (WWDA) and the working group Teaching Astronomy for Development (TAD), which grew out of the Visiting Lecturers' Program (VLP), were all run by C46. When the IAU established the Office of Astronomy for Development in 2011, many of these functions were removed from the commission and in any case C46 ceased to exist in 2015 when all the old commissions were disestablished. In 2015 the Office for Young Astronomers took over the running of the ISYA. The history of C38 and C46 represents a time of active change in the way the IAU was engaging with people. It was more than just a union for scientific research, but in the world of scientific unions, it was remarkable for taking an active hands-on role in implementing social change. In the history of these two commissions, the Swiss astronomer Edith Müller played a leading dynamic role. She served as president of C46 (1967-73), of C38 (1985-88) as well as IAU General Secretary (1976-79).