Why was the 1-metre Yerkes telescope significant in the history of refracting telescopes?

The 1-metre (40-inch) refractor at Yerkes Observatory is historically significant as the largest refracting telescope ever built. Installed in 1897, it represented the pinnacle of refracting technology, featuring an objective lens designed by the renowned optician Alvan Clark.12

Beyond its size, the telescope was central to the vision of astronomer George Ellery Hale, who designed the observatory to integrate laboratories for optical, spectroscopic, and chemical research. This approach helped bridge the gap between traditional observational astronomy and the emerging discipline of astrophysics, establishing a model for modern research institutions.32

While the Yerkes refractor was used for vital work in solar and stellar spectroscopy, photographic parallaxes, and double-star observations, it also marked the end of an era. By the 20th century, the reflecting telescope became the dominant instrument for astronomical research due to its ability to be scaled to much larger apertures.21