The Yerkes (pronounced Yerkees) 40 inch refractor. The first large telescope built at the direction of George Ellery Hale in Lake Geneva, Wisconsin. Completed in 1895, it was one of the last large refractors. Because of poor observing conditions in Wisconsin, , Hale later moved to Pasadena, California to found observatories at Mt. Wilson and Mt. Palomar. He directed the construction of a 60" reflector, a 100" reflector, and last, the 200" reflector.....all the largest in the world, when they were built.