Optical telescope
The telescope is more a discovery of optical craftsmen than an invention of a scientist. The lens and the properties of refracting and reflecting light had been known since antiquity and theory on how they worked were developed by ancient Greek philosophers, preserved and expanded on in the medieval Islamic world, and had reached a significantly advanced state by the time of the telescope's invention in early modern Europe. But the most significant step cited in the invention of the telescope was the development of lens manufacture for spectacles, first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the Netherlands and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (refracting telescopes) appeared. The invention is credited to the spectacle makers Hans Lippershey and Zacharias Janssen in Middelburg, and the instrument-maker and optician Jacob Metius of Alkmaar.
Warner &amp; Swasey Company
The first Warner & Swasey telescope, built in 1881, was sold to Beloit College for its new Smith Observatory and had a 9.5-inch lens made by Alvan Clark & Sons. Among the notable instruments the company built were the telescopes for Lick Observatory (1888, 36-inch, refracting); the United States Naval Observatory (1893); Yerkes Observatory (according to the 50th-anniversary book, this was a 40-inch refracting telescope completed in time for display at the World's Columbian Exposition of 1893, although its installation at Yerkes was apparently in 1897); and Canada's Dominion Astrophysical Observatory (1916, 72-inch, reflecting). In 1919, the company's founders donated their private observatory in East Cleveland, Ohio to Case Western Reserve University. Today's Warner and Swasey Observatory grew from that facility.