On this day in Duluth in 1917, the Darling Observatory opened at 910 West 3rd Street. John H. Darling retired as an engineer for the Army Corps of Engineers in 1913and turned his full attention to his hobby: astronomy. In 1917 he privately funded the Darling Observatory atop Duluth’s Point of Rocks, roughly 325 feet above the lake. The stucco building featured a nineteen-foot dome. Its telescope, mounted on solid bedrock, had a nine-inch, 261-pound refracting lens with a focal length of 130 feet; Darling designed some of its components himself. The observatory included a lecture room that seated up to twenty, and Darling regularly conducted public sessions lasting up to three hours. The day after the observatory opened, the Duluth News Tribune ran an article stating “Another point of interest has been added to Duluth’s collection of features for the delectation of tourists and residents…. Star gazers and people who would like to identify the specific brand of cheese the moon is made of will be welcomed by Mr. Darling.” There was so much interest in Darling’s telescope that three days later the newspaper announced that the astronomer had to take reservations for his lectures: he asked potential audience members to send him a postcard with their phone number on it, and that he would then call them to let them know when they could attend. The observatory remained popular for some time: over 16,000 people visited the observatory in 1930. Read more about the Darling Observatory here.