The Art of Travel - Shifts and Contrivances Available in Wild Countries by Francis Galton
page 55 of 465 (11%)
page 55 of 465 (11%)
![]() | ![]() |
|
occulation, eclipse, etc., and the instant, a minute or two later, when
the sextant observation for time is made. All that a watch actually does is to beat seconds, and to record the number of beats. Now, a string and stone, swung as a pendulum, will beat time; and a native who is taught to throw a pebble into a bag at each beat, will record it; and, for operations that do not occupy much time, he will be as good as a watch. The rate of the pendulum may be determined by taking two sets of observations, with three or four minutes' interval between them; and, if the distance from the point of suspension to the centre of the stone be thirty-nine inches, and if the string be thin and the stone very heavy, it will beat seconds very nearly indeed. The observations upon which the longitude of the East African lakes depended, after Captain Speke's first journey to them, were lunars, timed with a string and a stone, in default of a watch. Hour-glass.--Either dry sand or water may be used in an hour-glass; if water be used, the aperture through which it runs must, of course, be smaller. CLIMBING AND MOUNTAINEERING. Climbing.--Climbing trees.--Colonel Jackson, in his book, 'How to Observe,' gives the following directions for climbing palms and other trees that have very rough barks:--"Take a strip of linen, or two towels or strong handkerchiefs tied together, and form a loop at each end, for the feet to pass tightly into without going through; or, for want of such material, make a rope of grass or straw in the same way. The length |
|