Sky & Telescope - August 2020 - 31

Saegmuller's Large Refractors
Original Location

Year

Objective Lens (and Maker)

Catholic University of America, Washington, DC

1890

9-inch f/12 (John Clacey)

Ladd Observatory, Brown University, Rhode Island

1891

12-inch f/15 (Brashear)

U.S. Naval Observatory, Washington, DC

1892

12-inch f/15 (Alvan Clark & Sons)

Georgetown University, Washington, DC

1893

12-inch f/13.5 (John Clacey)

Chamberlin Observatory, Denver, Colorado

1894

20-inch f/15 (Alvan Clark & Sons)

Manila Observatory, Manila, the Philippines

1895

19-inch f/14 (Jakob & Matthias Merz)

Jesuit Saint Ignatius College, Valkenburg aan de Geul, the Netherlands

1896

9-inch f/12 (John Clacey)

Home of Charles E. Hequembourg, Dunkirk, New York

1897

9-inch f/13 (optician unknown)

Bausch & Lomb Observatory, Rochester, New York

1912

10.5-inch f/15.5 (Zeiss)

if that wasn't bad enough, the Americans bombed the facility
ﬁve days later.
After the Battle of Manila, Victor Blanco, a meteorologist
with the U.S. Army (who later became director of the Cerro
Tololo Inter-American Observatory in La Serena, Chile),
visited the damaged observatory. His encounter with the
remains of the 19-inch appears in part at the beginning of
this article. The melted objective lens, as Blanco evocatively
wrote, ". . . looked like a huge tear drop."
War also played a role in the story of another Saegmuller
telescope. During World War II, the German army occupied
Valkenburg aan de Geul, home to the Jesuit college's 9-inch
refractor. The Germans used the college as a Reichsschule -
an elite school for educating young men selected to be future
leaders of the Third Reich.
After the war, the telescope was assumed to have either
been destroyed or taken by the Germans. What the Jesuits
didn't know was that in September 1944, with the Allied
Forces advancing and the Germans retreating, the town's
people dismantled most of the telescope (leaving the pier
behind) and hid it in a seminary in the nearby city of
Maastricht. The telescope lay there forgotten until it was
rediscovered in the 1970s. The instrument was then moved
to the Limburg Observatory in Heerlen, in the southeast of
the Netherlands. There it was refurbished, minus the original pier, which remains to this day in the deserted dome at
Valkenburg aan de Geul.
The other six Saegmuller refractors fared better, and all
but one remains operational. Currently out of commission is
the 10.5-inch that Saegmuller built for the Bausch & Lomb
building in Rochester. In 1941 the telescope was moved to the
Sommers-Bausch Observatory at the University of Colorado
in Boulder, where it remained in service until 1971. After
that, the Zeiss objective was removed for use in a solar telescope, and the rest of the instrument was put on display in
the lobby of the university's Fiske Planetarium. In 2013 the

telescope went into storage, awaiting the day when the University of Colorado Heritage Museum will display it again.
Charles Hequembourg's refractor is now at Mount Union
College in Alliance, Ohio, sporting a new 8.5-inch objective
lens. The 12-inch built for the Ladd Observatory remains at
its original location, having been refurbished in 2012.
The U.S. Naval Observatory refractor has been signiﬁcantly modiﬁed and, unfortunately, its hand wheels and star
dials are long lost. The refractor was relocated to another
dome in the 1950s to make room for another telescope and
suffered the same fate yet again some years later. From there,
the refractor was placed into storage until the late 1970s,
when observatory staff refurbished it and returned to its
original location.
After the astronomy department at Georgetown University was closed in 1972, students formed the Georgetown
Astronomical Society to oversee the use of the facility's
12-inch Saegmuller telescope. This instrument's hand wheels
and star dials remain in working order, though the dome has
some problems.
The 20-inch refractor at the Chamberlin Observatory in
Denver underwent restoration between 2011 and 2014 to
correct an accumulation of damage. You can watch a video
showing how easily the large telescope moves with the hand
wheels at https://is.gd/Chamberlin.
Although Saegmuller produced observatory refractors for
only a short time, his innovative mounts resulted in telescopes that were much easier to use compared to similar
instruments of the era. Despite the ravages of time, 120 years
later six of Saegmuller's large refractors remain in use today
- a testament to his engineering and manufacturing skills.

TED RAFFERTY is a retired U.S. Naval Observatory astronomer. He participated in the restoration of two 12-inch
Saegmuller refractors - one at his home institute, the other at
Georgetown University.
sk yandtelescope.org * AUGUST 2 02 0

https://www.is.gd/Chamberlin http://www.skyandtelescope.org

Sky & Telescope - August 2020

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