Refracting telescope of aperture 18cm, "Comet Seeker and Richest Field Telescope", by Horace E. Dall, with 3-element f/4.5 object glass, altazimuth mounting, three eyepieces and erecting prism
Refracting telescope of aperture 18cm, "Comet Seeker and Richest Field Telescope", by Horace E. Dall, with 3-element f/4.5 object glass, altazimuth mounting, three eyepieces and erecting prism