<p>I believe this is a 20 cm <a href="https://en.wikipedia.org/wiki/Grubb_Parsons" rel="noreferrer">Grubb</a> refractor with a focal length of 248 cm.</p>
<p><a href="https://www3.astronomicalheritage.net/index.php/show-entity?identity=180&amp;idsubentity=1" rel="noreferrer">This page</a> mentions some of the telescopes at the Jagiellonian Observatory in 1964:</p>
<blockquote>
<p>In 1964, a jubilee 600 years of Jagiellonian University, was
celebrated in Cracow. Five domes were erected in Fort Skała,
Astronomical Observatory Nicolaus Copernicus of the Jagiellonian
University. Two domes were built for telescopes, made by Carl Zeiss of
Jena; the Grubb refractor and Grubb astrograph have been moved to the
remaining domes, one remained empty</p>
</blockquote>
<p>It is also listed as one of the observing instruments in <a href="https://ui.adsabs.harvard.edu/abs/1970AcA....20..283K/abstract" rel="noreferrer">this 1970 paper on &quot;Occultations of Stars by the Moon Observed at the Cracow Astronomical Observatory in the Year 1969&quot;</a>: &quot;Grubb refractor with Mertz objective, D = 203 mm, f = 247.7 cm&quot;.</p>
<p><a href="http://historia.ptma.pl/index.php/Historic_telescope_of_Poland" rel="noreferrer">A page on &quot;Historic Telescopes of Poland&quot;</a> includes this note for the Jagellonian University Observatory: &quot;Other instruments found at Kraków in 1931 were a Grubb-Merz equatorial, 20.3 cm aperture, 248 cm focal length&quot; -- which suggests it was made prior to the 1930s....</p>
<p>I'd say your eyeball measurement from the photo are pretty good....</p>
<p>(I've actually visited this observatory to work with a friend and give a talk, although I don't think I saw any of the telescopes. It's kind of a funky site, based on late 19th/early 20th C Austrian fortifications. I was told that back in the 1960s, there was a dome that was built too small for its intended telescope, but the person who ordered it was too high in the Party hierarchy to be questioned, so they went ahead and built it anyway. Possibly that was the dome that &quot;remained empty&quot;?)</p>

CC BY-SA 4.0
2023-06-22T23:01:08.413Z
What an interesting story and answer; thank you! It must have been a lot of fun researching :-)
uhoh
CC BY-SA 4.0
2023-06-23T06:25:38.837Z
Can anybody speculate on how much that weighed? Is that its mount in the background, i.e. he's carrying it to or from dry storage?
Mark Morgan Lloyd
CC BY-SA 4.0
2023-06-23T14:14:35.010Z
@MarkMorganLloyd Since the caption says he's on the "terrace", I'd speculate it's _not_ the mount in the background. No idea about the weight.
Peter Erwin
CC BY-SA 4.0
2023-06-23T23:59:15.160Z
@MarkMorganLloyd I don't think it's incredibly heavy. One would want the thinnest possible tube walls to allow for quick thermal equilibration. For most types of observing a small amount of tube deflection under gravity for a simple refractor doesn't cause much of a problem, so it doesn't have to be super-duper rigid. Also he looks to have a pretty substantial build http://149.156.201.144/galeria/gallery.html cf. "With son Jerzy, 1938" https://i.sstatic.net/Y3jnj.jpg
uhoh
CC BY-SA 4.0
2023-06-22T18:04:00.357Z
2023-06-23T13:57:42.573Z
2023-06-23T13:57:42.573Z
Peter Erwin
<p>As a son of Kazimierz Kordylewski I lived with him in the 60s in the Krakow Observatory and I remember this telescope very well.
It was called &quot;luneta ekspedycyjna&quot; and it was portable. To make it lightweight and possible to carry, its body was made of aluminium. Usually it was mounted on the fork seen in the background. Every night it was being taken back inside the building after the observations on the terrace were finished. It was usually housed in the coffin-like, long wooden box in which it traveled with Kordylewski during his international expeditions, i.e around African continent, and to many other locations. In the late 50s it was being mounted each night on a temporary wooden post installed on Polish Baltic Sea beaches, where it was used by Kordylewski for his program to popularize Astronomy among the vacationers passing by along the beach on evenings in many Polish sea resorts along Baltic Sea border. Every night it was put back to the box and traveled to the next location. To fit in the box, the tube, which was composed of sections of various sizes, was contractable by sliding them back to make the tube shorter. I am guessing that the instrument was originally built in Krakow in the manufacture of &quot;Zaklad Aparatow Naukowych&quot; run by Kordylewski in the 40s. I am not sure, but is possible that the optics used was saved from formerly German Observatory in Bialkowo, which was reclaimed by Kordylewski after Silesia was liberated by the Soviet Army. Along with the other telescope &quot;Amerykanka&quot;, donated to Krakow by Harvard University, the &quot;ekspedycyjna&quot; was the preferred instrument used by Kordylewski for his field observations. To my knowledge this telescope is still in possession of Krakow Observatory at Skala, probably housed in its box and therefore not readily seen by visitors.
In the picture behind Kordylewski there is another telescope covered with a tent. It was build by him and was his personal property. Painted blue, it is now in use in the Frombork Observatory at Gora Zurawia and is called &quot;Kordylewski Telescope&quot;.</p>

CC BY-SA 4.0
2023-07-13T11:42:47.603Z
(+1) This is wonderful history and information! Thanks for posting!
Ed V
CC BY-SA 4.0
2023-07-14T00:35:10.027Z
Thank you so much for stopping by and taking the time to write such a thorough and detailed answer telling us about both the telescope and the astronomer holding it! I am really touched to know that they both travelled so much together and took part in so much public outreach, and may have sparked a lifelong interest in science in many of those vacationers. Public outreach is one of those things that separate astronomy from so many other fields of science and this and other things I've read show he was a real ambassador of astronomy to the public.
uhoh
CC BY-SA 4.0
2023-07-14T00:50:38.310Z
...as well as to those closer to home of course. *Welcome to Stack Exchange!* There are [almost 200 SE sites here](https://stackexchange.com/sites#percentanswered) including [Biology](https://biology.stackexchange.com/) and [Esperanto](https://esperanto.stackexchange.com/). Here's an unanswered question for you: [Is this a real "double microscope" with two stages and two sets of objectives? Is it used in biology?](https://biology.stackexchange.com/q/100999/27918)
uhoh
CC BY-SA 4.0
2023-07-13T10:42:07.247Z
2023-07-13T10:42:07.247Z
Les
<p>The following questions touch on <a href="https://en.wikipedia.org/wiki/Kordylewski_cloud" rel="noreferrer">Kordylewski clouds</a></p>
<ul>
<li><a href="https://astronomy.stackexchange.com/q/54051/7982">Can dark matter accumulate at Lagrange points?</a></li>
<li><a href="https://astronomy.stackexchange.com/q/54065/7982">Are dust-dust collisions necessary to explain Kordylewski clouds at Earth-Moon L4/5? Aren&#39;t the cross-sections, number density timescales too small?</a></li>
</ul>
<p>The Wikipedia article links to the image below. It shows Polish astronomer <a href="https://en.wikipedia.org/wiki/Kazimierz_Kordylewski" rel="noreferrer">Kazimierz Kordylewski</a> on the terrace of the Astronomical Observatory of the Jagiellonian University in Krakow and is dated April 1964. Kordylewski is holding a sizable refracting telescope. If Kordylewski is 1.7 m tall, then the main body of the telescope is 2.2 meters long, though if the top section is a long glare shield then it's also about 1.7 meters, not counting a ~0.2 m focusing tube, and the tube would be about 20 cm diameter with an objective diameter perhaps 10-20% or so smaller.</p>
<p><strong>Question:</strong> What telescope is Polish astronomer Kazimierz Kordylewski holding in this April 1964 photo at the Jagiellonian University Observatory in Krakow?</p>
<p>If it's the main telescope of the observatory, an answer like &quot;The Jagiellonian University Telescope&quot; is insufficient. At least a few optical details (f/no. aperture, air-spaced or not, when it was manufactured, who made it) are need to help us understand the telescope.</p>
<hr />
<p><a href="https://i.sstatic.net/lkcGa.jpg" rel="noreferrer"><img src="https://i.sstatic.net/lkcGa.jpg" alt="Kazimierz Kordylewski - the photo was taken on the terrace of the Astronomical Observatory of the Jagiellonian University in Krakow (April 1964) Source: Urania Monthly of the Polish Society of Amateur Astronomers, No. 4, April 1981, photo on the fourth page of the cover" /></a></p>
<blockquote>
<p>Polski: Kazimierz Kordylewski - zdjęcie wykonano na tarasie Obserwatorium Astronomicznego Uniwersytetu Jagiellońskiego w Krakowie (kwiecień 1964)<br />
Date: April 1964<br />
Source: Urania Miesięcznik Polskiego Towarzystwa Miłośników Astronomii, nr 4, kwiecień 1981 roku, zdjęcie na czwartej stronie okładki</p>
</blockquote>
<p>Google translation:</p>
<blockquote>
<p>English: Kazimierz Kordylewski - the photo was taken on the terrace of the Astronomical Observatory of the Jagiellonian University in Krakow (April 1964)<br />
Date: April 1964<br />
Source: Urania Monthly of the Polish Society of Amateur Astronomers, No. 4, April 1981, photo on the fourth page of the cover</p>
</blockquote>
<p>Source: <a href="https://commons.wikimedia.org/wiki/File:Kazimierz_Kordylewski_-_1964.jpg" rel="noreferrer">File:Kazimierz Kordylewski - 1964.jpg</a></p>
<hr />
<p>Lame photogrammetry for ratios:</p>
<p><a href="https://i.sstatic.net/t59uo.jpg" rel="noreferrer"><img src="https://i.sstatic.net/t59uom.jpg" alt="lame photogrammetry on https://commons.wikimedia.org/wiki/File:Kazimierz_Kordylewski_-_1964.jpg" /></a> click for full size</p>

<telescope><history><identify-this-object><observatory>
What telescope is Polish astronomer Kazimierz Kordylewski holding in this April 1964 photo at the Jagiellonian University Observatory in Krakow?
uhoh
# What telescope is Polish astronomer Kazimierz Kordylewski holding in this April 1964 photo at the Jagiellonian University Observatory in Krakow?

(Asked by: username_0 on 2023-06-22)

The following questions touch on [Kordylewski clouds](https://en.wikipedia.org/wiki/Kordylewski_cloud)

* [Can dark matter accumulate at Lagrange points?](https://astronomy.stackexchange.com/q/54051/7982)
* [Are dust-dust collisions necessary to explain Kordylewski clouds at Earth-Moon L4/5? Aren't the cross-sections, number density timescales too small?](https://astronomy.stackexchange.com/q/54065/7982)

The Wikipedia article links to the image below. It shows Polish astronomer [Kazimierz Kordylewski](https://en.wikipedia.org/wiki/Kazimierz_Kordylewski) on the terrace of the Astronomical Observatory of the Jagiellonian University in Krakow and is dated April 1964. Kordylewski is holding a sizable refracting telescope. If Kordylewski is 1.7 m tall, then the main body of the telescope is 2.2 meters long, though if the top section is a long glare shield then it's also about 1.7 meters, not counting a ~0.2 m focusing tube, and the tube would be about 20 cm diameter with an objective diameter perhaps 10-20% or so smaller.

**Question:** What telescope is Polish astronomer Kazimierz Kordylewski holding in this April 1964 photo at the Jagiellonian University Observatory in Krakow?

If it's the main telescope of the observatory, an answer like "The Jagiellonian University Telescope" is insufficient. At least a few optical details (f/no. aperture, air-spaced or not, when it was manufactured, who made it) are need to help us understand the telescope.

---

[![Kazimierz Kordylewski - the photo was taken on the terrace of the Astronomical Observatory of the Jagiellonian University in Krakow (April 1964) Source: Urania Monthly of the Polish Society of Amateur Astronomers, No. 4, April 1981, photo on the fourth page of the cover](https://i.sstatic.net/lkcGa.jpg)](https://i.sstatic.net/lkcGa.jpg)

> Polski: Kazimierz Kordylewski - zdjęcie wykonano na tarasie Obserwatorium Astronomicznego Uniwersytetu Jagiellońskiego w Krakowie (kwiecień 1964)  
> Date: April 1964  
> Source: Urania Miesięcznik Polskiego Towarzystwa Miłośników Astronomii, nr 4, kwiecień 1981 roku, zdjęcie na czwartej stronie okładki

Google translation:

> English: Kazimierz Kordylewski - the photo was taken on the terrace of the Astronomical Observatory of the Jagiellonian University in Krakow (April 1964)  
> Date: April 1964  
> Source: Urania Monthly of the Polish Society of Amateur Astronomers, No. 4, April 1981, photo on the fourth page of the cover

Source: [File:Kazimierz Kordylewski - 1964.jpg](https://commons.wikimedia.org/wiki/File:Kazimierz_Kordylewski_-_1964.jpg)

---

Lame photogrammetry for ratios:

[![lame photogrammetry on https://commons.wikimedia.org/wiki/File:Kazimierz_Kordylewski_-_1964.jpg](https://i.sstatic.net/t59uom.jpg)](https://i.sstatic.net/t59uo.jpg) click for full size

**Tags:** telescope, history, identify-this-object, observatory

---

## 2 answers

### Answer by username_1 on 2023-06-22. Score: 18

I believe this is a 20 cm [Grubb](https://en.wikipedia.org/wiki/Grubb_Parsons) refractor with a focal length of 248 cm.

[This page](https://www3.astronomicalheritage.net/index.php/show-entity?identity=180&idsubentity=1) mentions some of the telescopes at the Jagiellonian Observatory in 1964:

> In 1964, a jubilee 600 years of Jagiellonian University, was
> celebrated in Cracow. Five domes were erected in Fort Skała,
> Astronomical Observatory Nicolaus Copernicus of the Jagiellonian
> University. Two domes were built for telescopes, made by Carl Zeiss of
> Jena; the Grubb refractor and Grubb astrograph have been moved to the
> remaining domes, one remained empty

It is also listed as one of the observing instruments in [this 1970 paper on "Occultations of Stars by the Moon Observed at the Cracow Astronomical Observatory in the Year 1969"](https://ui.adsabs.harvard.edu/abs/1970AcA....20..283K/abstract): "Grubb refractor with Mertz objective, D = 203 mm, f = 247.7 cm".

[A page on "Historic Telescopes of Poland"](http://historia.ptma.pl/index.php/Historic_telescope_of_Poland) includes this note for the Jagellonian University Observatory: "Other instruments found at Kraków in 1931 were a Grubb-Merz equatorial, 20.3 cm aperture, 248 cm focal length" -- which suggests it was made prior to the 1930s....

I'd say your eyeball measurement from the photo are pretty good....

(I've actually visited this observatory to work with a friend and give a talk, although I don't think I saw any of the telescopes. It's kind of a funky site, based on late 19th/early 20th C Austrian fortifications. I was told that back in the 1960s, there was a dome that was built too small for its intended telescope, but the person who ordered it was too high in the Party hierarchy to be questioned, so they went ahead and built it anyway. Possibly that was the dome that "remained empty"?)

> **Comments:**
> **username_0**: What an interesting story and answer; thank you! It must have been a lot of fun researching :-)  
> **username_2**: Can anybody speculate on how much that weighed? Is that its mount in the background, i.e. he's carrying it to or from dry storage?  
> **username_1**: @MarkMorganLloyd Since the caption says he's on the "terrace", I'd speculate it's _not_ the mount in the background. No idea about the weight.  
> **username_0**: @MarkMorganLloyd I don't think it's incredibly heavy. One would want the thinnest possible tube walls to allow for quick thermal equilibration. For most types of observing a small amount of tube deflection under gravity for a simple refractor doesn't cause much of a problem, so it doesn't have to be super-duper rigid. Also he looks to have a pretty substantial build http://149.156.201.144/galeria/gallery.html cf. "With son Jerzy, 1938" https://i.sstatic.net/Y3jnj.jpg  

---

### Answer by username_3 on 2023-07-13. Score: 6

As a son of Kazimierz Kordylewski I lived with him in the 60s in the Krakow Observatory and I remember this telescope very well.
It was called "luneta ekspedycyjna" and it was portable. To make it lightweight and possible to carry, its body was made of aluminium. Usually it was mounted on the fork seen in the background. Every night it was being taken back inside the building after the observations on the terrace were finished. It was usually housed in the coffin-like, long wooden box in which it traveled with Kordylewski during his international expeditions, i.e around African continent, and to many other locations. In the late 50s it was being mounted each night on a temporary wooden post installed on Polish Baltic Sea beaches, where it was used by Kordylewski for his program to popularize Astronomy among the vacationers passing by along the beach on evenings in many Polish sea resorts along Baltic Sea border. Every night it was put back to the box and traveled to the next location. To fit in the box, the tube, which was composed of sections of various sizes, was contractable by sliding them back to make the tube shorter. I am guessing that the instrument was originally built in Krakow in the manufacture of "Zaklad Aparatow Naukowych" run by Kordylewski in the 40s. I am not sure, but is possible that the optics used was saved from formerly German Observatory in Bialkowo, which was reclaimed by Kordylewski after Silesia was liberated by the Soviet Army. Along with the other telescope "Amerykanka", donated to Krakow by Harvard University, the "ekspedycyjna" was the preferred instrument used by Kordylewski for his field observations. To my knowledge this telescope is still in possession of Krakow Observatory at Skala, probably housed in its box and therefore not readily seen by visitors.
In the picture behind Kordylewski there is another telescope covered with a tent. It was build by him and was his personal property. Painted blue, it is now in use in the Frombork Observatory at Gora Zurawia and is called "Kordylewski Telescope".

> **Comments:**
> **username_4**: (+1) This is wonderful history and information! Thanks for posting!  
> **username_0**: Thank you so much for stopping by and taking the time to write such a thorough and detailed answer telling us about both the telescope and the astronomer holding it! I am really touched to know that they both travelled so much together and took part in so much public outreach, and may have sparked a lifelong interest in science in many of those vacationers. Public outreach is one of those things that separate astronomy from so many other fields of science and this and other things I've read show he was a real ambassador of astronomy to the public.  
> **username_0**: ...as well as to those closer to home of course. *Welcome to Stack Exchange!* There are [almost 200 SE sites here](https://stackexchange.com/sites#percentanswered) including [Biology](https://biology.stackexchange.com/) and [Esperanto](https://esperanto.stackexchange.com/). Here's an unanswered question for you: [Is this a real "double microscope" with two stages and two sets of objectives? Is it used in biology?](https://biology.stackexchange.com/q/100999/27918)  

---

