Yerkes Observatory's Refracting Telescope

Do you know where the Yerkes refracting telescope is? One of the largest refracting telescopes in the world, if not the largest (another large astronomical telescope – refractor is the Mount Wilson’s refracting telescope), it was built in 1897 by the Massachusetts astronomer, scientist and master optician Alvan Graham Clark. Clark’s family was engaged in producing astronomical telescopes and lenses – this definitely influenced Clark to be serious in his astronomical pursuits.

The university based astronomical observatory has the world famous refracting telescope as its centerpiece among its astronomical telescopes - two of which are the 41 inches and 24 inch reflecting telescopes. The Yerkes refracting telescope itself has a 40 inch lens and a focal length of 20 meters.

The University of Chicago in Williams Bay at Wisconsin is the proud location of the Yerkes observatory. Built in 1897 by famous astronomer George Ellery Hale, the observatory was funded by Charles Tyson Yerkes, a transport tycoon and financier from Chicago, hence the name of the observatory. Hale was instrumental in convincing Yerkes to finance the building of the observatory, pointing out the nobility of its purpose. And indeed, Charles Tyson Yerkes was convinced to involve himself in this ambitious project, but strongly insisted that the refracting telescope to be built should be the largest in the world.

Today, the Yerkes observatory provides access to its facilities – the refracting telescope as well as the other astronomical telescopes - for scientific and stargazing researches and pursuits.