A magnetic compass, such as the Silva Ranger, points towards Magnetic North. Most maps are oriented to True North. The difference is the Declination. Declination is measured in degrees East or West. I find the conventions of declinations very confusing. Declination in the east is west, and west is east. Every time, I must think of the physical situation. Imagine a beach ball made of many pieces, each fat in the middle and tapering towards the ends. Hold it so that all the pieces come together at the top and bottom, and the fat parts are horizontal around the middle. Draw a belt around the middle. Label the top "North Pole", the bottom "South Pole", the belt "Equator", and the seams "lines of latitude". Now draw in the continent of North America. It doesn't need to be a good drawing, since it is entirely imaginary. Now make an "X" a little northwest of Hudson's Bay, Canada, and label it "Magnetic North". Got that? Mark a "M" at Massachusetts, "K" at Kentucky, and "C" at California. Draw a line from Kentucky to Magnetic North and another from Kentucky to True North. They should be almost overlapping. Do this at Massachusetts. The Magnetic North line is left or West of the True North line. In California, the Magnetic North line is to the right or East of the True North line. There is a declination map for the United States of America in the Silva Ranger Instruction Manual. (Note that Rensselaer and Washington Counties in New York have been ceded to Vermont!) If you have a Brunton Model 8040, then there is even a declination map printed right on the back of the compass mirror. Declination changes not only from one locality to another, but also with time at the same locality. In Kentucky, the declination has changed about 5ø since my farm was first surveyed shortly after the War of 1812. In Upstate New York, the declination has changed about 10ø since Kiliaen van Rensselaer "bought" it from the Indians in 1635. The effect of declination on a plot of your deed is to rotate it by that number of degrees. Big deal. If you don't know the declination where and when your parcel was surveyed, call it zero and you will have a map oriented to Magnetic North. Access to the entire text files is thru .