The largest telescopes in the world

The world's largest telescope today is of course the twin Keck
telescopes, even taken one by one. And before that, the largest
scope was the Russian 6-meter reflector. And before that the Hale
5-meter telescope, and before that the Hooker 2.5-meter telescope.

But before that?

I'd like to assemble a list of the world's largest telescopes, in
chronological order. Ideally it should cover all the time from
Galileo's telescope in 1609 to the present time, and be complete,
but quite naturally available information may be incomplete or
inaccurate particularly from the 1600's and 1700's.

Currently, the list looks as below. By a curious coincidence
Lord Rosse's 72-inch Leviathan was dismantled in 1908, the same
year that Mount Wilson's 60-inch reflector became operational;
since the latter happened on 20 Dec 1908, Lord Rosse's Leviathan
was most likely dismantled before that date. Thus, there ought to
be some time (several months?) during 1908 when neither the
Leviathan nor Mt Wilson's 60-inch was the world's largest telescope.
But I don't know which other telescope was the largest immediately
before Mt Wilson's 60-inch. Anybody got an idea?

I also have a lot of gaps in my list before 1783, when William
Herschel finished his 20 foot f.l. (0.43 meter aperture) reflector,
so any information there is welcome. I'm also not sure whether
Herchel's 40-foot reflector remained operational all the time
until 1845 (a few decades after Herschel's death in 1822); if not,
there's another gap there which needs to be filled.

Note that the size of scopes were usually given as the focal
length in feet; not until the Leviathan the aperture was given
as the "size" instead. Thus, both Lord Rosse's Leviathan
and Galileo Galilei's scope were 6 foot scopes.... :-)

Anyway, here's my list. Comments, additions and corrections
are welcome!

================================================== ============
World's
largest Aperture Scope
scope in

1609 0.044 m Galileos 5-6 foot f.l. refractor, x33
1640 ca ? 15-20 foot refractors
1656 0.07 m Christian Huygens 23 f.l. foot refractor, x100
1670 ca ? Hevelius 140 foot f.l. refractor
1675 (The "air telescope")

1730 ca (Large reflectors)

1774 (William Herschel starts making telescopes)
1783-1789 0.43 m William Herschel's 20 foot f.l. reflector, Bath,
England
1789-1845 1.22 m William Herschel's 40 foot f.l. reflector, Bath,
England
1845-1908 1.83 m Lord Rosse's Leviathan, 6 foot ap., Birr Castle,
Ireland; dismantled 1908
1908 ?????? ?????????? (some other scope - which?)
1908-1917 1.5 m 60-inch, Mt Wilson, California, USA; operational
20 Dec
1917-1948 2.5 m Hooker 100-inch, Mt Wilson, California, USA
1948-1974 5.0 m Hale 200-inch, Mt Palomar, California, USA
1974-1990 6.0 m Bolshoi, Nizhny Arkhyz, Russia
1990- 10.0 m Keck, Mauna Kea, Hawaii, USA
================================================== ============





--
----------------------------------------------------------------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://www.stjarnhimlen.se/
http://home.tiscali.se/pausch/

Paul Schlyter wrote:

The world's largest telescope today is of course the twin Keck
telescopes, even taken one by one. And before that, the largest
scope was the Russian 6-meter reflector. And before that the Hale
5-meter telescope, and before that the Hooker 2.5-meter telescope.

But before that?

I'd like to assemble a list of the world's largest telescopes, in
chronological order. Ideally it should cover all the time from
Galileo's telescope in 1609 to the present time, and be complete,
but quite naturally available information may be incomplete or
inaccurate particularly from the 1600's and 1700's.

Currently, the list looks as below.
...

I think you should include the Lick observatory 36-inch refractor,
who was followed shortly by the Yerkes scope as biggest in the world.

- Alex

Paul Schlyter wrote:

1908-1917 1.5 m 60-inch, Mt Wilson, California, USA; operational
20 Dec
1917-1948 2.5 m Hooker 100-inch, Mt Wilson, California, USA


I recall reading that the Hooker 100-inch didn't reach operation
until 1918. Hence there was a few-month window when the 72-inch
reflector at the Dominion Astrophysical Observatory, in Victoria,
British Columbia, Canada, held the title as the largest operating
telescope in the world.

--
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Mark Gingrich San Leandro, California

On Tue, 30 Sep 2003 21:58:29 +0200, Paul Schlyter
wrote:


The world's largest telescope today is of course the twin Keck
telescopes, even taken one by one. And before that, the largest
scope was the Russian 6-meter reflector. And before that the Hale
5-meter telescope, and before that the Hooker 2.5-meter telescope.

But before that?

I'd like to assemble a list of the world's largest telescopes, in
chronological order. Ideally it should cover all the time from
Galileo's telescope in 1609 to the present time, and be complete,
but quite naturally available information may be incomplete or
inaccurate particularly from the 1600's and 1700's.

Paul-

Fun project. I assume your interest here is in _astronomical_ telescopes? I only
ask this because I doubt that Galileo's telescope was the largest telescope in
the world at the time, although it was certainly the first that we know to have
been used as a truly astronomical instrument. This raises the interesting
question of whether there have been any non-astronomical telescopes since that
time that were actually the largest telescopes in the world.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Mark Gingrich wrote:

Paul Schlyter wrote:

1908-1917 1.5 m 60-inch, Mt Wilson, California, USA; operational
20 Dec
1917-1948 2.5 m Hooker 100-inch, Mt Wilson, California, USA

I recall reading that the Hooker 100-inch didn't reach operation
until 1918. Hence there was a few-month window when the 72-inch
reflector at the Dominion Astrophysical Observatory, in Victoria,
British Columbia, Canada, held the title as the largest operating
telescope in the world.

The Hooker had some problems after seeing first light on November 1,
1917. Whether or not it was "operational" depends on one's definition
of the term. The Hooker did work from the beginning but was still being
tuned up for a while. Hale wrote in his Annual Report of the Director
at the end of 1917 that the Hooker was "not in commission" so the claim
that it "didn't reach operation until 1918" above is correct (although
first light was only two months before Jan 1, 1918). When did the
72-inch go into operation? If early in the year it should surely get to
claim the title of World's Largest for at least a short time.

From "Building the 100-inch Telescope" on the Mount Wilson Observatory
web site at http://www.mtwilson.edu/his/art/g1a4.htm:

"The telescope was not without some problems, but they were all readily
solved. The removable sections of the telescope tube that support the
secondary mirrors were not rigid enough, so compression rings were added
around them. The large, movable observing platform had to be partially
reconstructed. The clock drive had a periodic error that was traced to
the springing of a shaft in the drive train. An additional bearing
solved this problem. The optics and the spectrograph, the telescope's
primary research tool, performed up to the highest expectations. In
comparisons of plates taken with the 60- and 100-inch telescopes, some
of them exposed simultaneously with identical equipment on the
telescopes, the full theoretical gain of the larger instrument was
attained. The 100-inch not only worked, but it would be as powerful a
research instrument as anyone could have hoped."

Mike Simmons

Paul Schlyter wrote:

I'd like to assemble a list of the world's largest telescopes, in
chronological order.

I've always been fascinated by this and hoped that someone would put
such a list together. There was a great article in Sky and Telescope a
few years ago that should help but I can't locate it. It had a list of
all of the world's largest telescopes of various designs and included
their commissioning dates. The section on refractors should prove
useful as that's where the older instruments are.

Currently, the list looks as below. By a curious coincidence
Lord Rosse's 72-inch Leviathan was dismantled in 1908, the same
year that Mount Wilson's 60-inch reflector became operational;
since the latter happened on 20 Dec 1908, Lord Rosse's Leviathan
was most likely dismantled before that date. Thus, there ought to
be some time (several months?) during 1908 when neither the
Leviathan nor Mt Wilson's 60-inch was the world's largest telescope.
But I don't know which other telescope was the largest immediately
before Mt Wilson's 60-inch. Anybody got an idea?

Probably the Yerkes 40-inch refractor. If one discounts large speculum
metal mirrors then this is certainly the case.

1917-1948 2.5 m Hooker 100-inch, Mt Wilson, California, USA

November 1, 1917 was first light. As has been noted elsewhere, it was
not used for research until 1918.

1948-1974 5.0 m Hale 200-inch, Mt Palomar, California, USA

The correct location name is "Palomar Mountain".

As with the Sky and Telescope article, it would be interesting to
separate telescopes by design as well. The 40-inch refractor remains
the world's largest of its kind despite being well over a century old.
Surely that deserves some special recognition! :-)

Mike Simmons

In article ,
Chris L Peterson wrote:


Fun project. I assume your interest here is in _astronomical_ telescopes? I
only
ask this because I doubt that Galileo's telescope was the largest telescope
in
the world at the time, although it was certainly the first that we know to
have
been used as a truly astronomical instrument. This raises the interesting
question of whether there have been any non-astronomical telescopes since
that
time that were actually the largest telescopes in the world.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Chris,

I remember a very interesting article in Sky & Tel several years ago.
It was about a lens or mirror, touted as the world's largest, that was
displayed or possibly even mounted at about the turn of the 19th
century. Either a World's Fair or possibly the Colombian Exposition?
Anyone recall the details??

Starry Skies,
Rich

Richard DeLuca wrote:

In article ,
Chris L Peterson wrote:


Fun project. I assume your interest here is in _astronomical_ telescopes? I
only
ask this because I doubt that Galileo's telescope was the largest telescope
in
the world at the time, although it was certainly the first that we know to
have
been used as a truly astronomical instrument. This raises the interesting
question of whether there have been any non-astronomical telescopes since
that
time that were actually the largest telescopes in the world.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Chris,

I remember a very interesting article in Sky & Tel several years ago.
It was about a lens or mirror, touted as the world's largest, that was
displayed or possibly even mounted at about the turn of the 19th
century. Either a World's Fair or possibly the Colombian Exposition?
Anyone recall the details??

Starry Skies,
Rich

The mounting and tube for the Yerkes 40-inch refractor were on display
at the Columbian Exposition in Chicago in 1893. Could that be what you
were thinking of?

Mike Simmons

In article
,
Richard DeLuca wrote:



It was about a lens or mirror, touted as the world's largest, that was
displayed or possibly even mounted at about the turn of the 19th
century.


Excuse me- I meant the beginning of the 19th century here sigh.

In article
,
Richard DeLuca wrote:



Excuse me- I meant the beginning of the 19th century here sigh.

ARRGH!!
20th Century. Gonna take a nap now........