The modern professional forecaster would scorn to consult the entrails. There are however many amateur forecasters who foretell weather by their aches and rheumatic pains. Probably there is a high correlation factor between body sensations and dampness; and some individuals are quite sensitive to changes in both relative and absolute humidity. This, however, does not always mean that a storm is approaching. Humidity or dampness is only one factor and may be quite local, whereas most storms are wide-spread. THE WEATHER MAP The official forecaster consults a daily weather map and certain auxiliary maps which show changes in pressure and temperature for twelve hours or more. He examines closely the contours of pressure as shown on the map. The synoptic map, as it is called, because it is a glance at weather conditions over a large area at one and the same moment, is a map on which are plotted pressure, temperature, wind direction, velocity and rainfall. The lines of equal pressure or isobars generally curve and inclose what is known as a cyclonic centre, or depression or LOW. The arrows point in, but not exactly toward the centre of the depression. On the map there will probably appear also an area of high pressure where the surface air flows leisurely outward and away from the place of highest pressure. Such an area is called an anticyclone, a word first used by Sir Francis Galton in 1863 to designate not only high pressure, but general flow of the air in a reversed or opposite direction to that of the low area or cyclone. The word cyclone was first used by Piddington in 1843 in describing the flow of the air in the typhoons of the East Indian Seas. It is from the Greek and literally means the coils of a serpent. The word cyclone must possess some special merit in the minds of journalists for it is quite commonly misused for tornado in descriptions of the smaller and more destructive storm. THE LOW Cyclone is simply the generic name for a large rotating air mass. It is a barometric depression or LOW and is characterized by a flow of air inward and around a moving centre. The air circulation is counter-clockwise in the northern hemisphere and clockwise in the south. Perhaps if the earth stopped rotating and there was no planetary circulation, with the great west-moving trades and east-moving "westerlies," the arrows on the weather map would all point directly toward the centre of the LOW; but, as things are, there are some very good reasons why air can not move directly into a LOW, that is at right angles to the isobars. Moreover, the weather map does not indicate the true flow of the air, for observations of the wind made at the ground tell only a part of the story of the balance which the flowing air must maintain under the action of various forces, such as gravitation, rotational deflection, centrifugal tendency, and the various expansion and compression forces.