The following warnings of the approach of a typhoon, and directions for avoiding the most dangerous part of it, are taken from the China Sea Directory:  The earlier signs of a typhoon are clouds of a cirrus type, looking like fine hair, feathers or small white tufts of wool, traveling from east or north, a slight rise in the barometer, clear and dry weather, and light winds.  These signs are followed by the usual ugly and threatening appearance of the weather which forbodes most storms, and the increasing number and severity of the gusts with the rising of the wind.  In some cases one of the earliest signs is a long heavy swell and confused sea, which comes from the direction in which the storm is approaching and travels more rapidly than the storm’s center.  The best and surest of all warnings, however, will be found in the barometer.  In every case there is great barometric disturbance.  Accordingly, if the barometer falls rapidly, or even if the regularity of its diurnal variation be interrupted, danger may be apprehended.  No positive rule can be given as to the amount of depression to be expected, but at the center of some of the storms the barometer is said to stand fully 2 inches lower than outside the storm field.  The average barometric gradient, near the vortex of the most violent of these storms, is said to be rather more than 1 inch in 50 nautical miles.  As the center of the storm is approached the more rapid become the changes of wind, until at length, instead of its direction altering gradually, as is the case on first entering the storm field, the wind flies around at once to the opposite point, the sea meanwhile breaking into mountainous and confused heaps.  There are many instances on record of the wind suddenly falling in the vortex and the clouds dispersing for a short interval, though the wind soon blows again with renewed fury.

In the northern hemisphere when the falling barometer and other signs create suspicion that a typhoon is approaching, facing the wind and taking 10 or 12 points to the right of it, will give the approximate bearing of its center.  Thus, with the wind NE., the center will probably be from S. to SSE. of the observer’s position.  However, it is difficult to estimate the center of the vortex from any given point.  This partly arises from the uncertainty as to the relation between the bearing of the center and the direction of the wind, and greatly from there being no means of knowing whether the storm be of large or small dimensions.  If the barometer falls slowly, and the weather grows worse only gradually, it is reasonable to suppose that the storm center is distant; and conversely, with a rapidly falling barometer and increasing bad weather the center may be supposed to be approaching dangerously near.

Practical Rules.—­When in the region and in the season of revolving storms, be on the watch for premonitory signs.  Constantly observe and carefully record the barometer.