The construction of world-class telescopes on the top of the mountain brought many challenges to the founders of the Observatory. Rugged roads and even rougher terrain limit access to the mountains. Despite this, talent unions from Harvard University, the University of Southern California and Carnegie have also begun to build observatories. The new site ordered two telescopes, a 40-inch Alvan Clark instrument and a 13-inch refractor. Harvard astronomers began using the Observatory in the late 1880s. Erosion of tourists and landowners has made things difficult, and the Observatory website has been closed for some time. The planned 40-inch telescope was transferred to the Yerkes Observatory in Illinois. In the end, Hale and others decided to return to Mount Wilson to build a new telescope there. As part of a new advance in astronomy, Hale wants to conduct stellar spectroscopy. After repeated and repeated negotiations, Hale signed a contract to lease 40 acres of land at the top of Mount Wilson to build an observatory. In particular, he wanted to build a solar observatory there. It took a few years, but in the end, four huge telescopes, including the world’s largest solar and stellar instruments, will be built on the mountains. Using these facilities, astronomers such as Edwin Hubble made major discoveries about stars and galaxies.