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IanL
16-03-2008, 11:38 PM
Intresting article on Horace Dall of the Dall Kirkham system

http://uk.geocities.com/martinmobberley/dall.html

Merlin66
17-03-2008, 02:46 AM
They don't come much better than Horace! Unfortunately in todays era of "30 second" sound bites, new amateurs don't seem to have the same need/ wish/ desire to grind and build instruments. It seemed to have died out in the 70's.

How many of us, I wonder, started out with a basic 6" f8 and a couple of Ramsden ( what's that?... like an Ethos??) eyepieces............... Ah those were the days.

Kokatha man
17-03-2008, 07:44 AM
I did brudda - but them days is long, long gone; drifted back into the days of yore with all those other memories; like how much it used to cost to buy.....and, when I was a boy we used to.....

As for yer ramsdens, I had t' dreams about thems whilst I saved me pennies; makin' do with those huygens things!

MikeyB
17-03-2008, 08:03 AM
Fascinating article, Ian - thanks for posting it.

Dennis
17-03-2008, 08:46 AM
Hi Ian

What a fascinating man! His Jupiter (1956) & Saturn (1976) film photos are quite extraordinary. Thanks for the link.

When I’m next out with my M180 DK I’ll think of the guy!

Cheers

Dennis

Satchmo
17-03-2008, 10:07 AM
Horace Dall is also well known amongst mirror makers for the `Dall Null test' : Galaxy Optics show such a test set up on their website. I first used it about 20 years ago though it is largely supersceded today by tests on-axis.

Geoff45
17-03-2008, 12:07 PM
Here is a Ramsden circa 1965 to bring back the old memories.

Kokatha man
17-03-2008, 02:30 PM
Struth Geoff! - I know I'm as guilty as the next old codger when it comes to 'memberin' the "good ol' days of my youth;" but those piccies brought me down with a thud bro!

I'm feelin' real old at the mo' - an unless you tell me that was a typo, and the ep was really pre WW2 I'm going out t' buy some "Grecian 2000" jist to make me feel better - not that there's too much hair for it to work on!

I have nothing left from the era I mainly referred to in my prior post, (late 50's - very early 60's) though I still have my 8" mirror and secondary (flat) from the early 70's.

As I tell people these days, you didn't have much/any choice but to "grind your own" in those days - even in the early 70's a 12 and a 1/2 inch Cassegrain, EQ with optional drive on pier was $2000 from "Astronomical Supplies" at Crows Nest. This was literally then a "Dream Scope" and that amount equates to 15+ thousand if compared to a basket of costs and wages etc today. "The good old days!"

Geoff45
17-03-2008, 03:12 PM
No this was bought in the 1960's. I was living in Zimbabwe (then Rhodesia) at the time and got it mail order from England. I think the Poms were a bit behind the time, because I remember Patrick Moore at the time describing English eyepieces as terrible--tiny lenses buried in a chunk of brass, so maybe what you could get in Oz at the time would have been more modern. As for grinding your own mirror--the only way to go in those days.
Geoff

Merlin66
17-03-2008, 07:30 PM
Geoff,
I wondered where I'd left my old one.... now I see you found it!!
It may have faded from the bright brass finish ( like all of us!) but instantly recognisable!!
A 1/2" focus... right?
I've still got the original 6" Wildey mirror ( signed, 1955) which started me on this crazy hobby.

Geoff45
17-03-2008, 08:51 PM
No it's NOT YOURS. This one is a 1/4" focus.
Geoff