In 1940 astronomy came back to life in St Andrews. Under the first director Erwin Finlay-Freundlich, an observatory was founded, telescopes were built, projects were planned, papers were written. The first astronomical research in St Andrews since the 17th century, the era of James Gregory. The most ambitious plan was the construction of the first telescopes of the Schmidt-Cassegrain type, a unique optical design to facilitate distortion-free wide-angle images while avoiding the pitfalls of the original Schmidt camera. After a half-scale pilot model, the Scott-Lang Telescope (SLT), the plan culminated in the inauguration of the James Gregory telescope in 1962. The JGT is a 37″ Schmidt-Cassegrain, until today the largest optics of this type and the largest operating optical telescope in the United Kingdom. It is the fundament for the astronomical research in St Andrews and an important part of Scottish heritage.

Over several decades the JGT and the SLT produced hundreds of kilograms of photographic plates with images of galaxies, asteroids, and comets. The entire scientific output of the telescopes fits into a large steel cupboard which even a strong person cannot move. In the early 1990s, two critical things happened: Astronomy merged with physics and moved to the School of Physics & Astronomy at North Haugh. The observatory became an outpost. Around the same time, the first digital CCD camera was implemented at the JGT. The output of the telescope is not anymore measured in kilograms, but in megabytes. Until today, the JGT remains active in clear nights and is still used for research and teaching.

An excellent and comprehensive book about the history of the observatory has been written by Ron Hilditch and is available through the university library:  Stars over St Andrews : 75 years of observational astronomy at the University Observatory, St Andrews, Scotland