Last Updated: Aug 24, 2018     Views: 135

Image: Disk Hoisted by Crane. Photograph by Ayres A. Stevens, Corning Glass Works. United States, Corning, NY. March 26, 1936. Glass slide: 8 x 10 cm. George V. McCauley Archive, Rakow Research Library, Bib ID: 116511. New York Digital Heritage Collections, ID: 1000093960.

Hello! Thank you for your question. The answer I am including here is pieced together from several newspaper accounts that appeared in print between July 7, 1935, and April 11, 1936, of the disk's more than 3,000-mile journey.

The Challenges

The July 7, 1935, issue of The Daily Oklahoman defines the problem: "How to pack for shipment across the United States the 20-ton, 200-inch mirror, a piece of glass the size of a fashionable night club dance floor."

The Index-Journal of Greenwood, South Carolina, reports on March 10, 1936, about the movement of the disk from the storage building onto a fifty-ton trailer, from which it would be transported to a special rail car: "Railroad officials said two days would be necessary to bolt and brace the 'eye' in place in the well on the special car."

The Decatur Daily Review, on March 11, 1936, explained how the disk was loaded into the rail car: "Standing on edge, the crate containing the mirror was lifted into a hole in the middle of the car.... It was necessary to stand the 200-inch disc on edge to provide clearance for railroad viaducts and overhead bridges." The train was to be comprised of a locomotive, the car with the disk, a boxcar containing equipment needed for unloading, and a caboose. The train was "expected to average between 25 and 30 miles an hour." Another article indicated the speed limit was 25 miles per hour.

The Route

The route, according to the article in The Decatur Daily Review, would use New York Central tracks to Cleveland, "where a switch will be made to the Cleveland, Chicago and Cincinnati lines. This road will be used to St. Louis, where the train will transfer to the tracks of the Chicago, Burlington and Quincy railroad." The final switch would occur in Kansas City to the Atchison, Topeka and Santa Fe system. The article claims that "it would be necessary to lower the rails in some places to enable the crate to pass under overhead obstructions."

200-inch Disk Route from Corning to Palomar

Image: Train route (in red) of the 200" disk from Corning to Caltech.

A March 27, 1936, article from The Daily Times of New Philadelphia, Ohio, explains, "The disc was encased in an all-steel crate weighing 15 tons. Five layers of heavy felt, three-fourths of an inch thick, protected the rime. The face of the disc was lined with cork three inches thick." The weight of the disk rested "on steel girders between which were layers of cork to protect against shocks." Finally, "Four six-inch axles with cork cushioning through the center of the eye practically held the crate to the car."

The Oakland Tribune (California) describes the disk's journey as "more closely guarded than any king on any similar travel." Before the truck could be unloaded at Caltech, workers planned to grease the shop floor "so the truck can be slipped, instead of driven, into position for the final unloading."

Archival Collections

In addition to newspaper accounts, we also hold several archival collections in the Rakow Research Library at The Corning Museum of Glass that might be of interest to you:

Additional Information

The archives for Corning Incorporated may have more specific information regarding the trip, security, and logistical matters. I suggest that you contact them as well if your research calls for more specific and verifiable detail.

Many of the newspaper articles that I cited in this response are available in the database, which is acessible whenever you are on the Museum campus and might also be available to you through your local library. (Individual subscriptions are available as well.)

A more extensive list of resources is available upon request. Please let us know if we can be of further assistance via Ask a Glass Question (, email (,
phone (607-438-5300), or text (607-821-4029).


Please do not hesitate to contact us with your glass-related questions in the future!





Comments (2)

  1. you will get a lot of information from a video and a book. The PBS video titled "Journey to Palomar" from 2008 is available now on YouTube. The book " the Perfect Machine" by R. Florence has great detail about Palomar, Corning, and more.
    by J D on Nov 30, 2020.
  2. As a former docent at Palomar Observatory, I researched this 11 years ago in order to make a model for the onsite museum. I have made models of the modified flat car # S-499010 in N, HO, S, O, and G scale. The information I got then was primarily from two sources, Journey to Palomar video, and the book The Perfect Machine....which have already been recommended. Just recently (December 2020) I received the magazine Central Highlight, volume 50, issue 4, which has an excellent description written by my friend David Ross. These 3 sources should give you everything you need.
    by jay d on Dec 22, 2020.

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