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Re: Home made level vial observation results & Amundson at the So. Pole
From: Wolfgang Hasper
Date: 2012 Feb 17, 14:23 +0100
I found pictures of an AH for mercury by Keuffel & Esser circa 1838-1908, (example 1) and another US Navy model, (example 2) presumably much later but virtually identical. The differences between this and the AH in the Amundson photos are very apparent in these nearly contemporary pieces.
1) there is a conspicuous lip on the tray giving it depth to retain the liquid.
2) there is no leveling mechanism at all, presumably because is would be superfluous with self-level mercury
3) there is clearly a funnel like adaptation of one corner of the tray to make pouring off the liquid mercury into a vial easier.
4) there is a wind screen attachment, which would have been needed in the scene we see at the pole. (Note the flag whipping and the parkas worn being pushed back against the body in Amundson photo.)
I have never used a mercury AH but in high winds I presume even mercury would be disturbed, as suggested by both of these kits having wind-screens included.
5) they are rectangular rather than square or round
None of these characteristics are seen in the Amundson south pole photograph.
Randall F Morrow PT
Ergonomics Safety Consultant
Chronic Pain Program
Kaiser Permanente - Kern County - Bakersfield
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From: Wolfgang Hasper
Date: 2012 Feb 17, 14:23 +0100
Randall,
Amundsen states in his book he took three AH with him, two of black glass and one of mercury.
(Book is available as pdf online, I think there's a link in his Wikipedia entry)
There is the one famous photo taken somewhere unterway with the AH on a box and a fellow bendig over it, while the navigator stands back some meters with a sextant in his hand. Hi-res versions can be found online. Zomming in, it is clearly the black glass AH being used, levelling screws and two vials attached to the base plate are visible.
Black glass does not freeze unlike Mercury that cannot be used in severe cold.
Mercury is of course a lot easier and more reliably levelled, excluding any possible errors from that side.
Amundsen used the Mercury AH to take the real important sights at the pole, obviously it was not so cold there :o)
More intersting info on his and Scotts polar region CelNav is in
THE OBSERVATIONS OF AMUNDSEN AND SCOTT
AT THE SOUTH POLE
ARTHUR R. HJNKS, C.B.E., F.R.s.
AT THE SOUTH POLE
ARTHUR R. HJNKS, C.B.E., F.R.s.
in
TIlE
GEOGRAPHICAL
JOURNAL
GEOGRAPHICAL
JOURNAL
Vol em No 4 April 1944
it's available online, too but I do not have tha link handy. Any search engine will quickly retrieve it.
Best
Wolfgang
Gesendet: Donnerstag, 16. Februar 2012 um 22:49 Uhr
Von: Randall.F.Morrow@kp.org
An: NavList@fer3.com
Betreff: [NavList] Home made level vial observation results & Amundson at the So. Pole
Von: Randall.F.Morrow@kp.org
An: NavList@fer3.com
Betreff: [NavList] Home made level vial observation results & Amundson at the So. Pole
I found pictures of an AH for mercury by Keuffel & Esser circa 1838-1908, (example 1) and another US Navy model, (example 2) presumably much later but virtually identical. The differences between this and the AH in the Amundson photos are very apparent in these nearly contemporary pieces.
1) there is a conspicuous lip on the tray giving it depth to retain the liquid.
2) there is no leveling mechanism at all, presumably because is would be superfluous with self-level mercury
3) there is clearly a funnel like adaptation of one corner of the tray to make pouring off the liquid mercury into a vial easier.
4) there is a wind screen attachment, which would have been needed in the scene we see at the pole. (Note the flag whipping and the parkas worn being pushed back against the body in Amundson photo.)
I have never used a mercury AH but in high winds I presume even mercury would be disturbed, as suggested by both of these kits having wind-screens included.
5) they are rectangular rather than square or round
None of these characteristics are seen in the Amundson south pole photograph.
Randall F Morrow PT
Ergonomics Safety Consultant
Chronic Pain Program
Kaiser Permanente - Kern County - Bakersfield
NOTICE TO RECIPIENT: If you are not the intended recipient of this e-mail, you are prohibited from sharing, copying, or otherwise using or disclosing its contents. If you have received this e-mail in error, please notify the sender immediately by reply e-mail and permanently delete this e-mail and any attachments without reading, forwarding or saving them. Thank you.
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