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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.

On Sun, 20 Jun 2004 22:06:18 -0400 Jared Sherman
 writes:
> Ritchie are in Pembroke, MA now at www.ritchienavigation.com/ and you
> could
> give them a call to enquire.If you can send them a digital photo
> they may be
> able to identify the compass.
>
> The two issues are that the fluid be the right viscosity, and that
> it not
> dissolve anything. My impression is that the mysterious "compass
> fluid" sold
> at genuine marine prices is what we call kerosene in the States, aka
> "paraffin oil" in the UK. Much thinner than mineral oil. Of course
> kerosene
> comes in many grades, so the "compass fluid" probably is somewhat
> more
> refined than what you'd buy at a fuel station.
>
> ----- Original Message -----
> From: "Trevor J. Kenchington" 
> To: 
> Sent: Sunday, June 20, 2004 5:25 PM
> Subject: Refilling a compass, was: Compass tilt
>
>
> Jared wrote, in response to George:
>
> > 
> >
> > Johnson's confirm this to be simple mineral oil, with fragrence
> added.
> > Generic mineral oil from the pharmacy is sold unscented, typically
> at less
> > than half the cost. Of course, then the compass might not smell as
> sweet.
>
>
> I have a rather nice older, brass box-compass, less its box, picked
> up
> for next to nothing at a flea market years ago. However, its fluid
> had
> been drained off, making its card very unstable and the compass
> quite
> useless as anything but decoration. Can anyone suggest how I should
> determine whether it should be refilled with oil (Johnson's or
> otherwise) or spirit?
>
> I figure that getting a new box made would easy enough if I could
> refill
> the compass itself. Maybe I would also need to restore the seals to
> keep
> the fluid in. Still, the result should be prettier, better quality
> and
> likely cheaper than buying a new compass of the same type.
>
>
> This compass is identified as "Ritchie, Boston". It is marked in
> quarter
> points but also in degrees, from 0 to 360. I assume that the latter
> (rather than markings of 0 to 90 in each of four quadrants) dates
> the
> instrument to post-1920 but perhaps American practice turned to the
> 360-degree notation before the British did (and/or perhaps my memory
> of
> when the Royal Navy abandoned quadrantal notation is wrong).
>
>
> Trevor Kenchington
>
>
> --
> Trevor J. Kenchington PhD                         Gadus@iStar.ca
> Gadus Associates,                                 Office(902)
> 889-9250
> R.R.#1, Musquodoboit Harbour,                     Fax   (902)
> 889-9251
> Nova Scotia  B0J 2L0, CANADA                      Home  (902)
> 889-3555
>
>                      Science Serving the Fisheries
>                       http://home.istar.ca/~gadus
>

   

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