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Re: Refilling a compass, was: Compass tilt
From: Jared Sherman
Date: 2004 Jun 20, 22:06 -0400
From: Jared Sherman
Date: 2004 Jun 20, 22:06 -0400
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