While on the subject of trekking through the wilderness, I came up with some interesting posts and videos that document some of the skills lost through time and progress. Sure, we have GPS systems to locate our positions and help see us safely home, but to the hearty men and women on the frontier these were advancements in technology that were not to be imagined until the likes of Jules Verne gave us the vision of the world we have the luxury of taking for granted. Today we worry about finding charging stations and Rhino propane tanks. Then, you just might survive if you could find water to drink and dry tinder to start a fire. You can imagine how foreign this is to one who won't stay in a hotel room that doesn't have cable, a refrigerator, and an ice machine down the hall. Self deprecation aside, the skills described in recent posts are relevant to those who navigated the uncharted wilderness of the late eighteenth century. And certainly essential to groups of hearty trekkers undertaking a wilderness adventure. The last post covered basic navigation without the use of a map. This is a follow-up posting that will provide additional details factors that will influence how we navigate in the wilderness.
Using The Sun: While on the subject of 18th Century orienteering, I found this You Tube posting showing a method for finding True North using nothing more than a long stick on a sunny day. This method was described in an earlier issue of On The Trail magazine, and great periodical for people whose personas exist in the late 18th century. Unlike most of the other videos I reference, this production was not meant to appeal to the historical reenactor, but is accurate just the same. Do your best to ignore the jazzy sound track.
Nickle Knowledge: One important caveat is that this technique helps to locate Geographic North Pole (GNP), while using compass identified Magnetic North Pole (MNP). I dare say that one should stay with one or the other, since they can vary significantly depending on where you are on the globe.
From this diagram, you can locate the GNP, located at the center of the wheel, and the MNP, identified by the black dot above the blue-shaded region of the United States. The GNP can be identified using the shadow method on a cloudless day, and locating the North Star (Polaris) on a cloudiness night.
In the chart you will see that the Prime Meridian, which runs through Greenwich, England, is at the 3:00 position. You would have to move westward to 90 degrees West Longitude to enter that zone (blue) where the offset, or declination, of the lines point to GNP and MNP is minimal.
For a more detailed description of Magnetic and True North, along with the third concept of Grid North, click here. If you're interested. Or not. I won't judge.
Coincidences: There are lines where the MNP and the GNP align perfectly. This is called the agonic line. You can see that there regions in the United States where such alignment actually exists.
Now, if we assume our treks occur in the blue zone (see previous diagram), declination (the difference between GNP and MNP) is less of an issue. Then too, maps made during the period were probably createdlocally, and mapmakers used the most reliable tool available: the compass.
For now, I think it's important to understand the basics of how the compass works, and how to use its ability to point in a constant direction. From this, you can duplicate a path, providing you kept goods notes about both the direction you walked and the number of steps you took. This is not an exercise in wandering, but more one of taking advantage of the constant the compass provides, and using the recorded distance, that you provide.
