10 Warner & Swasey 40-inch assembly crew

Inside the rising dome walls that would house the 40-inch refracting telescope, workmen pause atop a huge masonry pyramid built to support the iron pillar of the massive equatorial mounting. The mechanical parts of the telescope, the dome, and the elevating floor were all designed and constructed by the Warner & Swasey Company of Cleveland, Ohio. Although the firm sold its first telescope, an 8-inch refractor, in 1880, only eight years later the company had successfully built the largest refractor in the world, the 36-inch of Lick Observatory. The Yerkes 40-inch would prove to be the largest successful refractor in the world, and the record would endure into the 21st Century. The optics for these Warner & Swasey telescopes were supplied by the firm of Alvan Clark & Sons located in Cambridgeport, Massachusetts.