Fred-In an attempt to take the heat off of you from "polite society", I pose the question of how many people does it take to screw in the russian telescope? Any guesses-Old Sailor
> From: Fred@acf.org
> Subject: [NavList 4548] Re: accurate sextant
> Date: Fri, 22 Feb 2008 17:59:19 -0500
> To: NavList@fer3.com
>
>
> Sorry Alex. I couldn't resist saying something. The Russian
> telescope is probably better than the upright prism binocs. I was
> going to make some joke with Russians as the butt of the joke about
> the inverting aspect, but thought it might offend someone, so said,
> essentially, nothing instead. Kind of like Polish jokes, such as,
> 'How many Poles does it take to screw in a lightbulb? Answer,
> 'Three, one to hold the lightbulb and two to turn the ladder.' But
> such jokes are no longer allowed, unfortunately, in polite society.
>
> Fred
>
> On Feb 22, 2008, at 2:56 PM, Alexandre E Eremenko wrote:
>
> >
> >
> > Dear Fred,
> >
> > On Fri, 22 Feb 2008, Fred Hebard wrote:
> >
> >> I'm mostly resisting any national comparison jokes here.
> >
> > I did not understand this remark. Would you explain,
> > perhaps off-the-list?
> >
> > Alex.
> >
> >> On Feb 22, 2008, at 10:38 AM, Alexandre E Eremenko wrote:
> >>> George,
> >>>
> >>>> What struck me was its rather strange
> >>>> (to me) construction, in that the
> >>>> index arm swings on the "wrong" side of the frame;
> >>>
> >>> This is not exactly so. The arm moves INSIDE the frame.
> >>> If you look carefully you see that the frame has
> >>> a complicated shape which allows the arm to move
> >>> inside. The handle is attached to the
> >>> "other part of the frame", behind
> >>> the arm. Of course you can call the part of the
> >>> frame behind the arm a bridge, but it is an integral
> >>> part of the frame. The purpose of this
> >>> arrangement is to protect the arm.
> >>>
> >>> Freiberger has similar construction of the frame.
> >>> In general Freiberger looks very similar, except
> >>> it does not have the inverting scope and does not
> >>> have the scale magnifier/illumination device.
> >>>
> >>>> I ask those familiar with this
> >>>> instrument whether they see any
> >>>> advantage in the straight-through, inverting,
> >>>> 6x telescope, compared with an
> >>>> equivalent, non-inverting, prismatic ocular
> >>>> of similar power and
> >>>> light-grasp? Presumably,
> >>>> the prismatic would be a bit heavier; are there
> >>>> other differences?
> >>>
> >>> It is very much lighter, and lets more light through.
> >>> In this telescope, the light passes through only two lenses.
> >>> All astronomical telescopes-refractors are made this way,
> >>> and the reason is to minimize the loss of light.
> >>> So the designers of this telescope surely had the
> >>> same reason.
> >>> In addition, this is the only "modern" sextant telescope
> >>> that has wires. Wires are handy for many adjustments,
> >>> and make it easier to hold the object in the center of
> >>> the field.
> >>>
> >>> In the old days (until approx. 1940-s) many sextants had
> >>> inverting scopes with wires. However the SNO scope has
> >>> a substantial advantage in comparison with these old
> >>> scopes: much larger field of view, and much larger
> >>> diameter of the objective lens. Again this lets more
> >>> light through.
> >>>
> >>> Alex.
> >>>
> >>>
> >>>
> >>>>
> >>
> >>
> >>
> >>>
> >
> >
> > >
>
>
>
>
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