An early illustration depicts the Great Refractor at Harvard College Observatory. It took its first look at the sky 175 years ago. It was funded by donations, including one from former president John Quincy Adams. It took the first daguerreotype (an early type of photograph) of a star, and remained a busy scientific instrument until the 1930s. It was used for educational outreach until the 1970s, when it was retired. It still takes occasional glances at the sky, though. [A. Sonrel/Harvard College Observatory/Wikipedia]