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I really do not want to prolong the subject of a glycerin/alcohol play on
words, as they serve the same purpose in a compass bowl, but my source
would not be the local pharmacy - Dow Chemical has no problem with either
understanding or supplying the same. Again, there seems to be no problem
with Vodka - that also qualifies as ethanol, etc.,  to which I am sure at
least some of us can testify. My comment about sailors using the compass
as a source of drink was really no joke, but a real problem of bygone
days - perhaps glycerin is not quite as tasty and thus found its way into
use - although I nerver personally tried it. Regardless, it should be
rather obvious that a variety of fluids may be used in the compass as a
damping material - the obvious criterion being a resistance to freezing
and a compatibility in all respects with the card, bowl, magnets, sealing
material, etc., being used.

On Wed, 23 Jun 2004 15:17:36 -0400 Jared Sherman
 writes:
> Henry, in the states we generally refer to ethanol, isopropanol, and
> methanol as "alcohol".
>
> Whatever a trihydric alcohol may be...if you went into any pharmacy
> and
> asked for alcohol, you would be offered one of the above--but never
> glycerin.
>
> Perhaps more to the point, when is the last time you knew of
> glycerine being
> professionally used in a compass?
> And if it is no longer in use, why was it phased out?
>
> ----- Original Message -----
> From: "Henry C. Halboth" 
> To: 
> Sent: Wednesday, June 23, 2004 2:37 PM
> Subject: Re: Refilling a compass
>
>
> Your dissertation on glycerin is a bit difficult to understand,
> since you
> allow that alcohol may be used in the magnetic wet compass. By
> definition
> glycerine is a trihydric alcohol, commonly referred to as glycerol
> and
> glycerine; further, as most modern compass manufacturers allude to
> "special" fluids being utilized in there compasses it would appear
> necessary to perform an analysis to be sure as to what constituents
> were
> actually included therein.
>
> I have no problem historically with allowing alcohol and water as
> the
> basic constituents of compass fluid or that petroleum distillates
> are now
> also used, but would respectfully invite your attention to glycerin
> and
> alcohol being alternately referred to in texts that apparently
> predate
> the experience of both your good self and that of your experts.
> Please
> refer to for starters only Knights Modern Seamanship, 10th edition,
> and
> Reisenberg's Standard Seamanship for the Merchant Service, 2nd
> edition,
> in both of which glycerin and water, and alcohol and water are
> referred
> to as floatation fluids for the magnetic compass card.
>
> For the benefit of those who have otherwise asked, I would quote
> from A
> Practical Manual of the Compass, US Naval Institute, 1921 edition,
> to the
> effect that "The bowl is entirely filled with liquid, 45% alcohol,
> and
> 55% distilled water." My notes of some 60-years ago give the same
> proportions except that they employ the then alternately employed
> term
> glycerin instead of alcohol. Regardless,  I would not employ any
> home
> brew fluid to make up a deficiency in a modern compass without
> completely
> evacuating and thoroughly cleaning the bowl - or at least consulting
> the
> manufacturer.
> By the way Vodka and water seems to remain an uncontested
> alternative.
>
> On Wed, 23 Jun 2004 11:58:09 -0500 RSPeterson
> 
> writes:
> > I've put myself out front on compass issues, so I best stand and
> > deliver.
> >
> >  From no sources or my experience do I find any reference to using
> > glycerin and water as a compass fluid.  I've talked to the old
> guys
> > and
> > checked every compass reference known and nothing on glycerin/H2O.
> > And
> > I've never seen a compass come across my bench in almost 20 yrs
> that
> > contained same though I've seen some strange home-brew
> concoctions.
> > My
> > concern is that glycerin and water will freeze.  Historically,
> there
> > have been only two compass fluids: alcohol/H2O and petroleum
> > distillate.  And all modern compasses use petroleum derivatives.
> > That's
> > it.  If others have references, I would like to review them 'cause
> > this
> > is an unknown technology to me.
> >
> > Ritchie was the first to develop the "wet-card" compass; previous
> to
> > that all compasses were "dry-card" compass of the British type.
> > Kelvin-White (later Danforth)  was the first to develop the
> > spherical
> > compass as against the Ritchie flat-top.
> >
> > I would like to hear more.  This is a good time of the year for me
> > to
> > respond;  "Schoooools, OUT for summer!"
> > Thanks.  -- Bob Peterson
> >
> >
> > Courtney Thomas wrote:
> >
> > > I'd appreciate your information regarding the proper mixture for
> a
> > > compass fluid.
> > >
> > > Thank you,
> > >
> > > Courtney Thomas
> > >
> > > Henry C. Halboth wrote:
> > >
> > >> It was my understanding that, starting from scratch, compass
> > fluid was a
> > >> proper mixture of glycerin and distilled water (my notes give
> the
> > >> correct
> > >> proportions if anyone is interested) - lacking that a good
> grade
> > of
> > >> Vodka
> > >> was always recommended as the fluid to get rid of a bubble.
> Many
> > years
> > >> ago there was always a problem with sailors tapping the compass
> > for a
> > >> surreptitious drink.
> > >>
> >
> >
> > --
> > Robert S. Peterson
> > 31 N Alfred, Elgin IL  60123  USA
> > 847/697-6491
> > Compass Adjusting & Repair for Lake Michigan Navigators Since 1985
> > Physics @ Bartlett HS
> > e-mail: rspeterson(at)wowway.com
> >
>

   

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