The Great Lick Refractor

Lick Observatory was built during the years 1880 to 1888. The 36-inch refractor was fabricated at the same time, and one dome was built specifically for this telescope. "36-inch" refers to the diameter of the refracting lenses, one of which is pictured at the right. When completed, the Lick Refractor was the largest refracting telescope in the world. Even today, it is second in size only to the 40-inch Yerkes Observatory refractor.

Located in the large dome of the main observatory building, the Great Lick refractor is 57 feet long, 4 feet in diameter, and weighs over 25,000 lbs! The two 36-inch diameter glass disks were fabricated in France, and ground and polished into lenses in Massachussetts by Alvan Clark and his son Alvan G. Clark. It was a considerable challenge to transport these large pieces of glass across the ocean by ship, then (after grinding and polishing) across the country by railroad, and finally up the long, winding road to Mt. Hamilton by horse and carriage. One of the original lenses broke in transit, and it took several years and 18 attempts to fabricate the replacement lens, which finally arrived on Mt. Hamilton in 1886, as recorded in this historical lens arrival photo from the Mary Lea Shane Archives of the Lick Observatory.

James Lick's Legacy

Eccentric businessman and real estate magnate James Lick donated the $700,000 needed to build a "telescope superior to and more powerful than any telescope yet made." A self-made millionaire bachelor with a fondness for monuments, Lick was of the age and personality that he wanted his name and reputation to live on after his death. He first considered constructing statues of himself and his parents to stand as a memorial for posterity. Not just average statues, these would have been built on the coast on a scale large enough to be seen from ships at sea!

It was pointed out that such statues would likely be targets for shelling during any future wars. Lick then changed his mind and decided to build a huge pyramid, larger than the Great Pyramid of Cheops, on 4th and Market Streets in San Francisco.

Fortunately, scientific acquaintances persuaded Lick to change his mind again and endow a project which was monumental not only in physical size, but also in its ability to further scientific research and give astronomers a better look at the Universe: the world's largest and most powerful telescope.

Lick Observatory was the first permanently occupied observatory in the world to be built on a mountaintop. James Lick considered several locations for the telescope before choosing Mt. Hamilton. At the time, observatories were typically built in cities. It was speculated that placing an observatory at a higher elevation might eliminate some atmospheric interference, allowing for better observing. This proved to be correct, and Lick Observatory's success set a trend towards building observatories on mountaintops rather than in cities.

Sadly, James Lick died before the Great Lick Refractor and Lick Observatory were completed. His body is interred at the base of the Refractor, marked with a bronze plaque honoring the man and his vision.

Lick Refractor in Action: Yesterday & Today

The Great Lick refractor was a premier research telescope for nearly a century. In 1892, E.E. Barnard surprised the world when he discovered Jupiter's fifth moon using this refractor. Because Galileo had discovered Jupiter's other moons two centuries before, people of the time assumed that Jupiter had no more than four moons. (Jupiter is now known to have at least 63 moons.)

Numerous photographs were produced with this telescope throughout the years using astronomical photographic plates consisting of glass coated with photographic emulsion. A selection of photographic prints from these plates is available in the Lick Gift Shop. The lunar photo series below was taken with the Lick Refractor during the 1930s. This series is still used throughout the world in science textbooks and online classes to illustrate lunar phases.

Mt. Hamilton photographer Laurie Hatch captured the photo to the right through the dome opening of the 36-inch Great Lick Refractor. Note the lens end of the telescope and a sunlit patch of the dome's magnificent inlaid hardwood floor. The dome is not usually open during the day because the telescope is typically used at night. However, on November 15, 1999, the Great Refractor followed the transit of planet Mercury across the face of the sun. A CCD camera was attached to the telescope, and a streaming video feed linked the camera to the Exploratorium in San Francisco. Exploratorium visitors could see this rare event as if they were watching from the 36-inch dome on Mt. Hamilton.

Although primarily of historical interest, the Lick Refractor is still used infrequently for research. Currently it is used to observe the separation and orbits of binary stars. It is often used as a teaching telescope for university and college astronomy classes as well as for NASA teachers workshops. The general public may view the heavens through the 36-inch refractor at the Lick Observatory Summer Visitors Program and Music of the Spheres concert series.

Daytime visitors are invited to look at the Great Lick Refractor and hear an informal Lick Observatory history talk. Please check in at the Gift Shop to participate. Tours are given approximately every half-hour during business hours, at no charge.

To learn more about the building of Lick Observatory and the life of James Lick, visit the Lick Observatory history pages.

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