Fernando Cabral wrote: >At first it came as a suprise to find that different >compasses will show completely different readings. 2, 3, 5 or even 10 degrees >east or west are quite common.
In my collection of oddities I have a small compass that may have been repaired or assembled incorrectly - whatever the cause it points the wrong way! Or was it made for the Southern hemisphere? :-) Alongside it is a hand-calibrated precision rule from a combination set by Starrett, a world-famous maker, with one edge calibrated "10 20 30 40 60 50 70 ..." Many engineering disasters resulted before someone spotted it. Tony Moss
