When I first visited Lowell Observatory in Flagstaff, Arizona, in 2004, I was afforded a behind-the-scenes tour of the 24-inch Alvan Clark & Sons refractor. It’s a gigantic telescope housed in its original 1896 dome. I was graciously allowed to move the beast around and climb the ladder at the tube’s front end to peer inside. The lens I saw there is a masterpiece of craftsmanship — made even more remarkable because it’s the product of a self-trained telescope-maker.

Alvan Clark became a telescope-maker when he was in his 40s, after a career as a portrait artist and engraver. While he went on to achieve international acclaim (and build the world’s five largest refractors), in his early career, he struggled to establish his reputation.

Clark’s budding astronomical career is the topic of the Summer/Fall Journal of the Antique Telescope Society. If you love astronomical history, check it out — and, if you have a chance, visit Lowell Observatory.

 Some 110 years after the 24-inch Clark’s installation, the scope still reveals celestial wonders to visitors weekly.