40" Refractor of Yerkes Observatory, Williams Bay, WI (May 2024) (Alexandr Zaytsev)

40" Refractor of Yerkes Observatory, Williams Bay, WI (May 2024)

Visiting the dome of the largest refractor in the world still remaining in operational condition (D=40" f/19): the D=102cm doublet lens based 1897 built Clark Refractor, also often referred to simply as the Great Refractor [1-3] of Yerkes Observatory [4, 5], Williams Bay, WI. All indoor images are taken while taking part in "Space & Spaces Tour" offered by the observatory (May 11, 2024).

The cross section of the (27m in diameter) main dome structure of the building taken from [6] is shown below. The most impressive feature of the design of the structure is the central section of the main dome floor built an elevator able to adjust to match the position of the telescope, as illustrated in [7, 8].

The revisions of this image are grouped as follows:

Revisions A-J are showing areas above the moving floor inside the main dome,
Image in revision K is taken from the ground floor inside the observatory building,
Revision L shows the view from the ground level in the vicinity of the main dome,
Revisions M-Q show areas below the moving floor of the dome where the base of telescope's pier and all the motors are located.

The outdoor views of the Yerkes Observatory taken on the same visit are available under [9].

[1] https://yerkesobservatory.org/science/telescopes.html

[2] http://www.scopeviews.co.uk/YerkesVisit.htm

[3] https://www.grainger.com/know-how/inspiration/kh-video-yerkes-observatory

[4] https://yerkesobservatory.org/

[5] https://www.instagram.com/yerkesobservatory/

[6] https://yerkesobservatory.org/wp-content/uploads/2022/07/[email protected]

[7] https://www.youtube.com/watch?v=iZSZOnzuWQ4

[8] https://www.youtube.com/watch?v=9lCJQ9wrUqY

[9] https://www.astrobin.com/2pozo6/B/

B

Title: The head of the mount, its coordinate circles and service platform

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C

Title: The world largest operational refractor in all its glory - configured for visual observations

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D

Title: Fully mechanized slit of the dome - opened in daytime

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E

Title: Eyepiece side view of the instrument

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F

Title: "Master ladder" used to reach the eyepiece in instrument positions when moving floor doesn't quite do the trick

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G

Title: Mechanics of the dome (part 1 of 4)

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H

Title: Mechanics of the dome (part 2 of 4)

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I

Title: Mechanics of the dome (part 3 of 4) - the dome split internal retractable water protection membrane

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J

Title: Mechanics of the dome (part 4 of 4) - one of the counter-balance assemblies for the floor elevator mechanism

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K

Title: Literally, the stairway to heaven, leading from the ground floor of the building to the entry point into 40" refractor dome

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L

Title: The gate to the keep of the castle... I mean the door of the lower section of the dome where the base of the pier is located

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M

Title: Modest base of the pier of the modest 40" refractor, completely detached from the rest of the dome structure.

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N

Title: The dome's movable floor - view from below

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P

Title: Stairways connecting 3 levels of the main dome: basement, elevator floor level and the inner balcony level above

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Q

Title: Main motor (in the cage in the middle) and the 3 driveshafts of the main dome floor elevator mechanism

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