18-inch Telescope and Dome

In May of 1894, Percival Lowell borrowed a 12-inch refractor from Harvard College Observatory and an 18-inch refractor from lensmaker John Brashear of the Allegheny Observatory in Pittsburgh, Pennsylvania. Alvan Clark designed an attachment that allowed the two telescopes to be mounted together. 

These two telescopes were among the first pieces of equipment on the observatory campus before Lowell contracted with the Alvan Clark & Sons Corporation to build the 24-inch Clark Telescope in 1895.