My friends and I recently celebrated the (now international) Day of Geology by visiting an old pegmatite open-pit mine. That was great fun, and we found some nice specimens, including some Garnets (not to be confused with Grenades (sorry, that’s a Swedish pun… I couldn’t resist…)).
On the way back, however, we found something else that was interesting. Near the entrance to the site, someone had dumped a truckload of stuff that appeared to come from an old nautical firm’s office or something. Many of the things were mouldy and disgusting, seeming to have been there for a while, but we found some stuff worth bringing home, for instance two pieces that appeared to have belonged to some kind of nautical instrument.
We first thought it might be parts of some kind of a sextant, but looking at images of such instruments didn’t bring a clear match. Therefore I contacted my father, who knows about these things, or in case he doesn’t, knows someone who does. A few weeks later, he had worked it out, having showed images of the things to friend of his who has for many years been captaining large ocean going vessels.
It appears that what we had found were pieces of a repeater compass (Swedish: pejlkompass), which is an instrument used for gauging the bearing to landmarks or, at sea, other vessels, over time. There are normally at least two, one on each wing of the bridge, on every modern larger vessel.