Mention of the Armstrong Dissapearing Gun at Fort Taiaroa has reminded me of a puzzle I encountered there. Around the upper rim of the gun pit are degree marks painted on the wall. They vary from exceedingly good clarity to poor and faded and don't appear to be touched up, I presume them to be original. The puzzle is this. Aligned with North, the marking is "0". Aligned with South is "180". No problems there. The difficulty relates to the other numbers which run ANTI-CLOCKWISE! That is, NW is 45, West is 90, SW is 135, SE is 225, East is 270, NE is 315. Why are they numbered this way? If they were for Reciprocal bearings (ie, if the breech is located at 90deg, the muzzle would be facing 270deg),N would be 180 and S 0 and the degrees should still run clockwise. Being anti-clockwise, they wouldn't be reciprocal for any other bearing (eg 127deg would show as 233deg, not 307deg reciprocal). The Fire control instruments from the plot room were electrical, so it wasn't because of the need for mirrors to transfer fire data.
I have asked some old gunners involved in Coastal Batteries from WW2 and they don't know why, and modern gunners go off on an explanation of Mils. But in both WW2 artillery fire orders and modern use of Mils, the compass is shown going clockwise. In fact in Maths, Surveying, Navigation and Cartography the compass always runs clockwise.
Can anyone explain? Are there any other 1880's forts elsewhere that still have similar markings?
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