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Tada, none, it clamps in.

Thanks,

Fred

On Feb 23, 2008, at 3:26 PM, james whitson wrote:

> 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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