Re: Another HD flat

Daniel A. Mitchell

From Palomar Observatory document …

"On March 26, 1936, the mirror blank began its 16-day trip by rail from Corning to the Caltech optical shop in Pasadena. The telescope project captured the public’s imagination, and all across the country thousands of people lined the train tracks to watch it pass.

It was shipped on NYC well-flat No. 499010. Many photos of this movement can be found online.

The glass blank did arrive in Pasadena and went to Caltech optical shop. It stayed there for a couple years while the mirror was ground and polished. The completed mirror was then trucked up the mountain to its present location at the observatory. The whole story can be found by searching at Caltech-Palomar and the Corning Glass Works.

The mechanical parts of the telescope mount were shipped through he Panama Canal to the west coast. They were much bigger and heavier than the mirror.

This 200” telescope remained the largest in the world for many years. Though now surpassed, it’s still a respectable instrument today.

Dan Mitchell

On Aug 2, 2019, at 3:59 PM, Daniel A. Mitchell <danmitch@...> wrote:

Sorry!  It’s probably true that many of the USERS of such large machines were also in the industrial east, but not ALL. Some HAD to go “out in interchange” … or be transferred from one car to another (unlikely). There were only a few places in the country where such things could be made, and they had to be shipped to wherever they were needed.

The huge items needed for the Manhattan Project (“Jumbo"), and the Palomar 200” telescope mirror being good examples of huge items being moved most of the way across the country. Not to mention the big battleship guns … these things moved back and forth across the country before, and during WWII; and for some time after. These things had short service lives and had to be relined. Most all the big 16”-gunned battleships were in the Pacific, and the only yard that could reline their guns was on the east coast. Such movements from Washington State and California to the east and back were common.

Dan Mitchell

On Aug 2, 2019, at 12:43 PM, Gatwood, Elden J SAD <elden.j.gatwood@...> wrote:

I have seen others like this, that were for creating things like large mill rolls, flywheels, and such.  They didn't use regular molds for these ingots, but made up special breakable molds, once poured a cooled, were broken to release the ingot.

These did not go out in interchange; I never saw one on somebody else's rails.

Elden Gatwood

-----Original Message-----
From: [] On Behalf Of David Soderblom
Sent: Friday, August 2, 2019 12:21 PM
Subject: [Non-DoD Source] Re: [RealSTMFC] Another HD flat

It says it’s an ingot, but it looks rough, like concrete.  And why the asymmetric shape?

David Soderblom
Baltimore MD USA

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