SIYHALF.TXT Compass Theory & Operation 6 Chapter 1/2 Compass Theory and Operation If you do not have a Silva Ranger compass, then skip to Chapter 1_C. Honest! I really didn't plan on a Chapter 1/2. There really is a god, and Her Name is Serendipity! Some people have complained that Chapter 1 is too long, and then I had to make it even longer to accommodate the new Ranger. There is a lot to cover in using the Silva Ranger, and you are learning to survey too. It might take more than one pass to understand it all. If it takes more than three passes, then complain. My address and phone number are at the end of the chapter. Don't think that you can take a shortcut by reading the little Instruction Manual. If you think that this technical writing is half-assed, then you oughta be enthralled by the Ranger Instruction Manual. This is one case where you should NOT read the instructions before operation. Silva's Instruction Manual is so bad that I must limit my warranty. WARRANTY NOTICE! The warranty of CAVE, Inc of the SURVEY IT YOURSELF: instructions will be VOIDed if you read the Silva Ranger Instruction Manual! I strongly suggest that you do not look at Silva's instructions before you look at mine, or you run the grave risk of declaring yourself stupid. Silva Compass now has a new and improved version of the old standby Ranger 15T. The author has not personally field tested this new and improved version, and makes no claims that it is fit for any purpose whatsoever, including Surveying It Yourself. Eventually, these new and improved upgraded Rangers will be given the cave test. Two previous models of the Ranger were used to survey many miles of cave under the most abusive of environmental conditions. Anything that goes into a cave can be pretested by being stirred in a bucket of sand and mud, rolled down a stone staircase, and then washed in a washing machine. And still work. You could depend on the old Rangers to get you to hell and back. Or at least to survey The Backdoor To Hell Cave. There is no magic in a compass, not even a fancy compass. If you thought that you were buying magic, then I will give you your money back. Reluctantly. I wish that you would have forewarned me. SIYHALF.TXT Compass Theory & Operation 7 The only thing that might pass for magic is that the red end of the compass needle points North. Even if you don't really understand it all, you can still survey it yourself. I have a Master's degree in geology, and I don't understand it all either. It is sufficient for many useful purposes to have an instrument which will point in the same direction as any other of its kind. This enables people to communicate direction on The Earth's surface, or indeed under The Earth's surface. You have probably used a common compass to tell which way was north. And I am sure that all of you have watched The Sun rise in The East, and set in The West. The mere fact that The Sun stays put and The Earth moves underneath it does not impair The Sun's usefulness for finding direction. Those of you who don't live in a cave or in a big city probably have watched The Sun rise in The East many times. You might have even noticed that The East isn't always in the same place. The mere fact that The East isn't always in the same place does not impair its usefulness for determining direction. If you give directions from Sunrise, you must take into account the fact that Sunrise moves. Maybe this doesn't make much difference for the job at hand, or maybe it does. You decide. For example, if you wanted to tell someone the direction from your house to the house in which your brother lives (without being there to point to it) you might say that it is the house towards where the sun rises and a little around to the right. If there are only a few houses in the village, this amount of precision might work just fine. If you are installing spaceport runway landing lights, it might not be good enuf. You decide. Hopefully, I have gotten this far without telling you anything that you didn't already know. A compass points North, just like a Sunrise points East. Knowing that, the next question should be, "What is the standard deviation?" If your question is, instead, "What is Standard Deviation?", then you are about to learn something new. If you have any rituals which must be first performed, then perform such rituals now. Hocus. Poke us. Standard Deviation is merely a way to come closer to the answer to the question, "How close should I expect to come to the truth?" Just like ole Sunrise, the direction in which the compass points isn't always the same. It might be good enuf for what you are doing, it might not. You decide. Standard Deviation is a more precise way to measure precision, used by people whose business it is to ask what the numbers mean. SIYHALF.TXT Compass Theory & Operation 8 All the fancy on the Ranger enables you to determine a direction precise to about one degree. This is quite sufficient for preliminary surveying, and most of the time this is all that you need. Even if you need more precision, it is usually well worth your while to do a preliminary survey. A precision of one degree is about what you can draw with a paper and pencil and ruler and protractor. Is that good enuf? You decide. Is it too good?? Most of the time I would be happy to have a freehand sketch on the back of an envelope. This, plus a cryptic description of what to find when you get there, has been the standard way to describe property since the invention of writing. If you need a more precise description, then with SURVEY IT YOURSELF: you have the instruments and instructions for doing so. Continue. There are a bunch of gadgets on the Ranger which increase its precision from that of a napkin sketch to pen & ruler quality. I'll tell you more about them when you need them. The Ranger compass can be used just like a tourist store compass to tell which way is north. The red end of the compass needle points north. This is good enuf to navigate while driving on unfamiliar roads, or to find your way back to the lodge. The Ranger compass can be used just like any decent hiking compass to orient maps and get directions precise to about ten degrees. Turn the compass until the arrow under the compass dial lines up with the compass needle. Read the direction from the compass dial on the edge towards the landmark in question. There is also a way to get a direction precise to one degree with the Ranger. You will learn how to do this when the proper time comes. Meanwhile, you can use the Ranger just like any other compass with which you are familiar. Ignore the gadgetry you don't need. No magic. Magic is for magicians and bankers. If anything about the compass seems like magic (except for the fact that the red end of the compass needle points north), then you had best think about it until the magic runs out. It might help to get out a map of someplace familiar (the United States for example) or better yet, a globe. If you have any problems with my instructions, then contact me. CAVE, Inc, 1/2 Fast Road, Ritner, KY 42639. Dave, 606/376-3137. If you have problems with the Silva Ranger instructions, then contact Silva Compass, Johnson Camping, Inc, POB 1602, Binghamton, NY 13902-1604. Customer "Service": 800/572-8822