Astronomer Clyde Tombaugh is shown in a now-famous photograph at the age of 24 with his "homemade" 9-inch Newtonian telescope in this image also shown in Elva R. O'Hara's Clyde W. Tombaugh: Farm Boy Reached for the Stars.

Shown in the photo, the telescope tube is marked with something like




along the length of the tube, and illegibly with


and some other markings in a different, light-toned printing around the circumference of the tube.

According to the linked article:

Tombaugh was born on Feb. 4, 1906, in Streator, Ill. He might have been a typical farm boy but for his one fascination: astronomy. Through the influence of his father and an uncle, the 12-year-old Tombaugh began observing the night sky. He spent hundreds of hours using a 9-inch telescope bought at Sears and Roebuck, learning to methodically identify stars and constellations as well as to observe the movements of the planets.

But on page 243 of Gary Leonard Cameron Iowa State University 2010 thesis Public skies: telescopes and the popularization of astronomy in the twentieth century it says:

Sears Roebuck had only a few cheap hand-held telescopes for sale in its catalogues from the 1920s to the 1940s. However, by 1961, Sears had a total of nine models of astronomical telescope for sale, all Japanese imports under the Tower label.

Question: So exactly what is the origin of Clyde Tombaugh's 8-inch Newtonian telescope?

Cropped from Elva R. O'Hara's Clyde W. Tombaugh: Farm Boy Reached for the Stars:

enter image description here

The description there says:

Image caption: Clyde W. Tombaugh shared a homemade telescope with his father and uncle. Photo courtesy of NMSU Library Archives and Special Collections

Description here says:

The astronomer Clyde Tombaugh, discoverer of Pluto here shown with his homemade 9-inch telescope. Date: circa 1930

  • $\begingroup$ @JamesK thanks, there's another error; "8-inch" in the first sentence needs to be changed to "9-inch". $\endgroup$
    – uhoh
    Aug 11, 2019 at 5:33
  • $\begingroup$ I'm not sure, you could read the printing on the telescope as "8 inch AP" $\endgroup$
    – James K
    Aug 11, 2019 at 5:36
  • $\begingroup$ @JamesK The block quote says 9 inch, I'd read 8 like you from the photo but it's low quality, so I'm now sticking with the cited authoritative source. I'll change it myself to be consistent with 9 used elsewhere in my post. $\endgroup$
    – uhoh
    Aug 11, 2019 at 5:38
  • 1
    $\begingroup$ Fair enough, It's no an answer, but that one looks homemade. The "OHIO" markings look like the pipe was designed for something else, and "Newtonian Telescope" looks to be hand stencilled. $\endgroup$
    – James K
    Aug 11, 2019 at 5:50
  • $\begingroup$ @JamesK I agree 100%. If it was from the Sears catalog it might have Sears & Roebuck written on it as well. $\endgroup$
    – uhoh
    Aug 11, 2019 at 5:54

1 Answer 1


In the first chapter of Out of the Darkness: The Planet Pluto, Tombaugh gives a colorful, personal account of his youth in Illinois and Kansas, including five telescopes:

  • his uncle's uncorrected 3-inch refractor
  • a 2.25-inch achromatic Sears-Roebuck refractor his father and uncle shared
  • a mediocre 8-inch reflector he made in 1926
  • a better 7-inch reflector he made for his uncle
  • an excellent 9-inch reflector he made in 1928

The last two benefited from optical testing in a storm cellar built extra long for that purpose. Tombaugh's planetary sketches using the 9-inch reflector got him the job at Lowell Observatory.

The same photo appears on page 23 with this caption:

Clyde W. Tombaugh, at the age of twenty-two, with his homemade 9-inch (22.9-centimeter) reflecting telescope on the family farm near Burdett, Kansas. This picture was taken in the summer of 1928, eighteen months before the discovery of Pluto.

APOD 1997-02-04 (© 1996 K. Beatty) shows him at age 89 with the same telescope in New Mexico.

  • 1
    $\begingroup$ excellent and well-sourced answer, thanks! $\endgroup$
    – uhoh
    Aug 11, 2019 at 15:58

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .