[Therion] grid alignment rotation

[Graham Mullan]

Ben

We've had similar problems, notably with some of Willie's data where he 
applied a correction that encompassed both compass error and 
declination. The result suggested was to insert a line

declination 0 degree

which zero's the declination correction. One can then add a line such as

calibrate compass +11.5

in our circumstances, not needed in yours where the alignment with grid 
north has already been made.

As far as UFS is concerned, it's also worth noting that Therion 
recognises the local grid so you can use

cs: OSGB:ST

Graham