Caption:
The 1.83-meter (72-inch)
Leviathan of Parsonstown
was the record largest telescope
(i.e., the telescope
with the largest primary)
until 1917 when it was superpassed by
the 2.54-meter (100-inch)
Hooker telescope
at Mount Wilson Observatory
in California
(see Wikipedia:
Timeline of telescopes, observatories, and observing technology: 1800s).
The Leviathan was operational
1845--c.1890
(see Wikipedia:
Leviathan of Parsonstown: Operation).