James Gregory (1638-1675) was a Scottish mathematician and astronomer at St. Andrews University. He is credited with being one of the founders of calculus and inventing the Gregorian telescope. He had plans to build what would have been the first observatory in the UK but died before it could be constructed. He used the King James Library at St. Andrews as his laboratory and marked out what would be considered one of the first meridian lines in the world across the library floor. This line became known as the Gregory meridian - and in addition to remaining on the library floor it is also now cast into the sidewalk outside Parliament Hall on South Street, St. Andrews.