Image 1 Caption:
The
Leviathan of Parsonstown
(reflector, primary diameter 1.83 m = 6 ft, operational 1845--c.1890)
was the record largest telescope
(i.e., the telescope
with the largest primary)
until 1917 when it was superpassed by
the Hooker telescope
(reflector, primary diameter 2.54 m = 100 in, operational 1917--present)
at Mount Wilson Observatory
in California
(see Wikipedia:
Timeline of telescopes, observatories, and observing technology: 1800--present).