of terrific energy and frequently cause terrible destruction of crops
and property on shore and of shipping at sea. Thunderstorms, often of
great violence, are frequent in May and June, before the commencement
of the rainy season. During July, August, September, and October the
rains are very heavy. The rivers and lakes are swollen and frequently
overflow, flooding large tracts of low country.

At Manila the average rainfall is stated to be from 75 to 120 inches
per annum, and there the difference between the longest and shortest
day is only 1 hour 47 minutes and 12 seconds. This rainfall, immense
though it be, is small as compared with that of other parts of the
archipelago; e.g., in Liano, NE. of Mindanao, the average yearly
downpour is 142 inches.

Gales.--The gales of the Philippines may be divided into three
classes, known by the local names of Colla, Nortada, and Baguio. The
Colla is a gale in which the wind blows constantly from one quarter,
but with varying force and with alternations of violent squalls,
calms, and heavy rains, usually lasting at least three days; these
gales occur during the southwest monsoon and their direction is from
the southwest quarter. The Nortada is distinguished from the Colla,
in that the direction is constant and the force steady, without the
alternations of passing squalls and calms. The Nortada is generally
indicative that a typhoon is passing not very far off. These gales
occur chiefly in the northern islands, and their direction, as the
name implies, is from the northward. Baguio is the local name for the
revolving storm known as the typhoon, which, being the more familiar
term, will be used in these notes.

Typhoons.--These storms have their origin to the east or to the
southeast of the Philippines, whence their course is westward, with
a slight divergence to the north or south, the average direction
appearing to be west by north. They occur in all months of the year,
but the greater number take place about the time of the equinoxes. The
most violent ones occur at the autumnal equinox, and on an average, two
or three occur every year, and sometimes one follows another at a very
short interval. It is believed that when one of these typhoons passes
a high latitude in September there will be another in October of that
year, and one may be looked for in November in a lower latitude. These
tempests are not encountered in latitudes below 9 degrees N. The rate
of progress of these s