We did not always have GPS, and we did not always have smartphones, and we did not always know where we were. It still happens that people get lost. At the beginning of _The Lost Art of Finding Our Way_ (Harvard University Press), physicist John Edward Huth tells how there is still danger out there. He once found himself beset in fog, kayaking off Cape Cod. It had happened before, and this time, before setting out, he had noted the waves, wind, and more. He was able to use these clues to get home even in the fog, but two other kayakers were in the same fog and were not so lucky, and he subsequently read about their disappearance in the newspaper. They didn't have his ability to read the signs, and when the fog descended, they probably were completely lost and paddled seawards. His book is dedicated to them, and if Huth has his way, there will be far fewer lost hikers and sailors. There are many primitive and refined methods of land and marine navigation described here. This entertaining book is not just a summary of such techniques, but an appreciation of the pre-smartphone cultures (Arab traders, Vikings, Pacific Islanders, and those scientific types from Europe, too) that used and developed them, and a call for us to lift our eyes from our screens. Huth encourages us to leave "the bubble" of electronic positioning and take a good look around. He has lead courses to train students in primitive navigation and it works. "I have found that students can become adept at reading star patterns, following the arc of the Sun across the sky, and predicting the weather. But to acquire these skills you absolutely must leave the bubble and look at the stars, the clouds, and the Sun."
What do people do when they are lost? Lost people wander out in loopy, ineffective paths that cross back on themselves. If they are observant enough to realize that they are back where they started, panic can increase. Sometimes they use folk advice to rescue themselves, like walking downhill until they find a creek that will lead downstream to civilization; if the stream goes into a swamp, they are worse off. There's a whole list of other ineffective behaviors which lost people perform besides random walks, like following any game trail or track they come across or obsessively attempting to head off in one absolute direction. Some tactics can be effective, like getting to a high point to get an overview of the territory. Huth allows technology to intrude here: a high point is better for cell phone coverage, too. Basic land navigation starts with "dead reckoning," which was good enough for Lewis and Clark. Huth says you can gain skills in dead reckoning, but that even with a compass an experienced pathfinder can expect a precision within five or ten degrees at best. Estimates of distance covered, based on speed, similarly are subject to distortion due to terrain or fatigue. Especially interesting are corrections navigators have known for centuries they had to make. Light from a star bends as it goes through the atmosphere, for instance, and is especially bent from stars that are close to the horizon; these are just the stars a navigator will be looking for, since the job in sighting with the sextant is to measure the angle between a star and the horizon below it. Navigators are not restricted to looking at the Sun, Moon, stars, and planets. If you know something about prevailing waves, tides, currents, and winds, you might be able to pick up clues to location; the Pacific Islanders were adept at this sort of wayfinding. If you are stuck at sea and don't know where you are, you might look to the sky to see land-based birds that are fishing but will soon return to land, and they can point the way. Take care not to confuse them with pelagic birds that spend all their time at sea except for nesting. In the old days, when ships and life were slower, a sailor might take a jaunt at sea with no provision for navigation except to ask passing ships about location. Readers of _Moby Dick_ will remember that it was fairly common for ships stop and have a social "gam." Even now, a navigator can get clues from spotting ships in their traffic routes, and Huth explains how even seeing airplanes in the sky can give navigational information.
Huth's book is sizeable, with good diagrams and maps. He is an inspired teacher, and obviously loves his subject, one that includes cosmology, physics, meteorology, history, legends, and psychology. You may not have a chance of using any of the techniques here. Huth warns, "All of these techniques are matters of habit. Reading about them can be a curiosity, but they need to be practiced." I'm not in mind to practice them, and chances are I am never going to need them, but Huth's guide to guides is fun to read, and is a little monument to human cleverness.