<p>According to Kenneth Glyn Jones' book  <a href="http://www.messier.seds.org/xtra/history/m-scopes.html" rel="nofollow noreferrer" title="Volume 2 of Practical Astronomy Handbooks, ISSN 0964-0320, Cambridge University Press, 1991, page 371">&quot;Messier's Nebulae and Star Clusters&quot;</a>, Messier used many different telescopes in his career, some of which are listed below, translated from Messier's 1807 &quot;Connaissance des Temps&quot; article <a href="https://gallica.bnf.fr/ark:/12148/bpt6k6510286w/f395.item" rel="nofollow noreferrer">&quot;Quatrième Recueil d'Observations astronomiques de 1765 à 1769&quot;</a>.</p>
<div class="s-table-container">
<table class="s-table">
<thead>
<tr>
<th></th>
<th>Telescope Type</th>
<th>Focal Length (ft)</th>
<th>Magnification</th>
<th>Owner</th>
</tr>
</thead>
<tbody>
<tr>
<td>1</td>
<td>Ordinary refractor</td>
<td>25</td>
<td>138</td>
<td></td>
</tr>
<tr>
<td>2</td>
<td>Achromatic refractor</td>
<td>10.5</td>
<td>120</td>
<td>M. de Courtanvaux</td>
</tr>
<tr>
<td>3</td>
<td>Achromatic refractor (Dollond)</td>
<td>3.25</td>
<td>120</td>
<td>Duc de Chaulnes</td>
</tr>
<tr>
<td>4</td>
<td>Ordinary refractor</td>
<td>23</td>
<td>102</td>
<td></td>
</tr>
<tr>
<td>5</td>
<td>Ordinary refractor</td>
<td>30</td>
<td>117</td>
<td>M. Baudoin</td>
</tr>
<tr>
<td>6</td>
<td>Campani refractor</td>
<td></td>
<td>64</td>
<td>M. Maraldi</td>
</tr>
<tr>
<td>7</td>
<td>Gregorian refractor</td>
<td>6</td>
<td>110</td>
<td>M. Lemonnier</td>
</tr>
<tr>
<td>8</td>
<td>Gregorian refractor</td>
<td>30</td>
<td>104</td>
<td></td>
</tr>
<tr>
<td>9</td>
<td>Newtonian refractor</td>
<td>4.5</td>
<td>60</td>
<td></td>
</tr>
<tr>
<td>10</td>
<td>Newtonian refractor</td>
<td>1</td>
<td>44</td>
<td>M. de Saron</td>
</tr>
<tr>
<td>11</td>
<td>Refractor</td>
<td>19</td>
<td>76</td>
<td>Paris Observatory</td>
</tr>
</tbody>
</table>
</div>
<p><a href="http://www.messier.seds.org/xtra/history/m-scopes.html" rel="nofollow noreferrer">According to Owen Gingrich</a>, Messier's favourite telescope is not listed above, and was a 32 ft Focal Length FL, 7.5-inch aperture Gregorian reflector with magnification 104x.</p>
<p>I cannot find any mention that any of Messier's telescopes survive, but lots of other 18th century French telescopes are around, e.g. <a href="https://www.proantic.com/en/999648-french-gregorian-telescope-18-eme-century.html" rel="nofollow noreferrer">here</a> or <a href="https://collections.musee-mccord-stewart.ca/en/objects/details/443459?ctx=b69850a490afc8164e860af22fa27416bca2f957&amp;idx=60" rel="nofollow noreferrer">here</a>, so it is possible a telescope used by Messier may still survive somewhere.</p>

CC BY-SA 4.0
2023-04-08T18:12:34.477Z
Thanks *this is wonderful!* For astronomical observations the aperture is an important parameter, I'm surprised that magnification was available but aperture diameter wasn't! Also Messier did a lot more than catalog his 110 objects, so could it have been possible that that work was done with a much more limited set of instruments?
uhoh
CC BY-SA 4.0
2023-04-08T13:15:19.297Z
2023-04-08T13:15:19.297Z
David Bailey
<p><a href="https://en.wikipedia.org/wiki/Charles_Messier" rel="noreferrer">Charles Messier</a> is known for (among other things) a <a href="https://en.wikipedia.org/wiki/Messier_object" rel="noreferrer">catalog of &quot;Messier objects&quot;</a>.</p>
<p>Neither article shows an image of &quot;Messier's telescope&quot;, though the latter includes:</p>
<blockquote>
<p>Since these objects could be observed visually with <strong>the relatively small-aperture refracting telescope (approximately 100 mm ≈ 4 inches) used by Messier to study the sky</strong>, they are among the brightest and thus most attractive astronomical objects...</p>
</blockquote>
<p><strong>Question:</strong> Which telescope(s) did Charles Messier use to catalog his 110 objects? Is the telescope (or telescopes) still around?</p>
<p>Note that after describing the advent (and invention) of the achromatic lens, Neil English in Figure 6.5 on page 92 in the chapter <em>Charles Messier, the Ferret of Comets</em> in <a href="https://link.springer.com/book/10.1007/978-3-319-97707-2" rel="noreferrer">Chronicling the Golden Age of Astronomy; A History of Visual Observing from Harriot to Moore</a> shows the following telescope with the caption:</p>
<blockquote>
<p>Fig. 6.5 A small refracting telescope by Dollond, similar to the best telescope used by Charles Messier. (Image courtesy of Wiki Commons <a href="https://en.wikipedia.org/wiki/File:Telescope_by_John_Dollond_in_VULibrary.JPG" rel="noreferrer">https://en.wikipedia.org/wiki/File:Telescope_by_John_Dollond_in_VULibrary.JPG</a>)</p>
</blockquote>
<p>but this is meant as an illustrative example only.</p>
<p><a href="https://i.sstatic.net/OUAA5.jpg" rel="noreferrer"><img src="https://i.sstatic.net/OUAA5m.jpg" alt="English: 4 inch refracting telescope by John Dollond (1706-1761) (tube) and J. Ramsted (mount). London, 18th cent. White hall of the Vilnius university library https://en.wikipedia.org/wiki/File:Telescope_by_John_Dollond_in_VULibrary.JPG" /></a> (click for full size)</p>
<blockquote>
<p>English: 4 inch refracting telescope by John Dollond (1706-1761) (tube) and J. Ramsted (mount). London, 18th cent. White hall of the Vilnius university library</p>
</blockquote>
<hr />
<p>Different (obviously) but related in History of Science and Mathematics SE:</p>
<ul>
<li><a href="https://hsm.stackexchange.com/q/6142/3869">Where are the mirrors of historic telescopes today?</a></li>
</ul>

<telescope><history><messier-catalog>
Which telescope(s) did Charles Messier use to catalog his 110 objects?
uhoh
# Which telescope(s) did Charles Messier use to catalog his 110 objects?

(Asked by: username_0 on 2023-04-07)

[Charles Messier](https://en.wikipedia.org/wiki/Charles_Messier) is known for (among other things) a [catalog of "Messier objects"](https://en.wikipedia.org/wiki/Messier_object).

Neither article shows an image of "Messier's telescope", though the latter includes:

> Since these objects could be observed visually with **the relatively small-aperture refracting telescope (approximately 100 mm ≈ 4 inches) used by Messier to study the sky**, they are among the brightest and thus most attractive astronomical objects...

**Question:** Which telescope(s) did Charles Messier use to catalog his 110 objects? Is the telescope (or telescopes) still around?

Note that after describing the advent (and invention) of the achromatic lens, Neil English in Figure 6.5 on page 92 in the chapter *Charles Messier, the Ferret of Comets* in [Chronicling the Golden Age of Astronomy; A History of Visual Observing from Harriot to Moore](https://link.springer.com/book/10.1007/978-3-319-97707-2) shows the following telescope with the caption:

> Fig. 6.5 A small refracting telescope by Dollond, similar to the best telescope used by Charles Messier. (Image courtesy of Wiki Commons <https://en.wikipedia.org/wiki/File:Telescope_by_John_Dollond_in_VULibrary.JPG>)

but this is meant as an illustrative example only.

[![English: 4 inch refracting telescope by John Dollond (1706-1761) (tube) and J. Ramsted (mount). London, 18th cent. White hall of the Vilnius university library https://en.wikipedia.org/wiki/File:Telescope_by_John_Dollond_in_VULibrary.JPG](https://i.sstatic.net/OUAA5m.jpg)](https://i.sstatic.net/OUAA5.jpg) (click for full size)

> English: 4 inch refracting telescope by John Dollond (1706-1761) (tube) and J. Ramsted (mount). London, 18th cent. White hall of the Vilnius university library

---

Different (obviously) but related in History of Science and Mathematics SE:

* [Where are the mirrors of historic telescopes today?](https://hsm.stackexchange.com/q/6142/3869)

**Tags:** telescope, history, messier-catalog

---

## 1 answers

### Answer by username_1 on 2023-04-08. Score: 4

According to Kenneth Glyn Jones' book ["Messier's Nebulae and Star Clusters"](http://www.messier.seds.org/xtra/history/m-scopes.html "Volume 2 of Practical Astronomy Handbooks, ISSN 0964-0320, Cambridge University Press, 1991, page 371"), Messier used many different telescopes in his career, some of which are listed below, translated from Messier's 1807 "Connaissance des Temps" article ["Quatrième Recueil d'Observations astronomiques de 1765 à 1769"](https://gallica.bnf.fr/ark:/12148/bpt6k6510286w/f395.item).

|  | Telescope Type | Focal Length (ft) | Magnification | Owner |
| --- | --- | --- | --- | --- |
| 1 | Ordinary refractor | 25 | 138 |  |
| 2 | Achromatic refractor | 10.5 | 120 | M. de Courtanvaux |
| 3 | Achromatic refractor (Dollond) | 3.25 | 120 | Duc de Chaulnes |
| 4 | Ordinary refractor | 23 | 102 |  |
| 5 | Ordinary refractor | 30 | 117 | M. Baudoin |
| 6 | Campani refractor |  | 64 | M. Maraldi |
| 7 | Gregorian refractor | 6 | 110 | M. Lemonnier |
| 8 | Gregorian refractor | 30 | 104 |  |
| 9 | Newtonian refractor | 4.5 | 60 |  |
| 10 | Newtonian refractor | 1 | 44 | M. de Saron |
| 11 | Refractor | 19 | 76 | Paris Observatory |

[According to Owen Gingrich](http://www.messier.seds.org/xtra/history/m-scopes.html), Messier's favourite telescope is not listed above, and was a 32 ft Focal Length FL, 7.5-inch aperture Gregorian reflector with magnification 104x.

I cannot find any mention that any of Messier's telescopes survive, but lots of other 18th century French telescopes are around, e.g. [here](https://www.proantic.com/en/999648-french-gregorian-telescope-18-eme-century.html) or [here](https://collections.musee-mccord-stewart.ca/en/objects/details/443459?ctx=b69850a490afc8164e860af22fa27416bca2f957&idx=60), so it is possible a telescope used by Messier may still survive somewhere.

> **Comments:**
> **username_0**: Thanks *this is wonderful!* For astronomical observations the aperture is an important parameter, I'm surprised that magnification was available but aperture diameter wasn't! Also Messier did a lot more than catalog his 110 objects, so could it have been possible that that work was done with a much more limited set of instruments?  

---

