h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

A mnemonic to convert a true course on a map or chart to the actual number on a compass.

Two Virgins Make Dull Company - Add Whiskey.

True course on the chart, adjusted for Variation (the difference from true north to magnetic north, depending on your approximate location) gives the Magnetic heading. A further adjustment for local magnetic error, Deviation (caused by local magnetic fields on your ship) Gives the course to be steered by your magnetic compass. Westerly corrections are added to the formula, while Easterly errors are subtracted.

We further add their address 'at 60 D ST'

60 times Distance (in any units) equal Speed (in units per hour) multiplied by Time .

The 60 converts hours to minutes.



Many years ago, at least 25 if not 30, my wife and I watched a series about memory on PBS. The host told us in one episode he would teach us how to finger-spell the deaf alphabet in the next half-hour. He had a story about each position of the fingers with an easily remembered link to the letter. One was 'R' where the index and middle fingers are crossed - sometimes when you try roller-skates you fall down and your legs are crossed in the air. To this day my wife and I can do all 26 letters almost without thinking.

I remember almost nothing else from the shows, although I think he tried to teach us how to associate names and faces, I am totally useless at that even in a small community. People often greet me by name and I have no idea who they are Fortunately my wife is better at such things.

F S

mnemonics. I am impressed.