Again, whip-cord, well-dried, may be hung against a wainscot, a small plummet affixed to it, and a line drawn at the precise spot it falls to. The plummet will be found to rise before rain, and fall when the prospect brightens.
Another device is to take a clean, unpainted strip of pine—say, twenty inches long, one wide, and a quarter of an inch thick—cut across the grain; then have a piece of cedar of the same size, but cut along the grain. Let these be glued together and set upright in a stand.
Before a rain-fall the pores of the pine will absorb moisture, and swell until the whole forms a bow; this will gradually straighten on the approach of fine weather.
There are two forms in which a balance is used that are interesting from the natural laws that govern their motions. In one a dry sponge that has been saturated in salt and water is nicely balanced against a small weight at the opposite end. The sponge becomes heavier or lighter according to the presence or absence of moisture, and any variation in this respect may be noted on the gauge above, to which the index finger on a dial points.
The simplest plan of all, and as good as any, is to place in an accurate pair of scales on one side a one-pound weight; on the other, one pound of well-dried salt. This swells and grows heavier on the approach of rain; when brighter skies return, the one-pound weight asserts itself once more.
VACATION DAYS—THE REASON WHY BOB COULD NOT GO A-FISHING.