360 KANSAS CITY REVIEW OF SCIENCE. 
The approach of a tornado may be known by ominous clouds appearing in 
the southwest and northwest. The clouds sometimes resemble the smoke of a 
hay-stack, at other times they appear like iridescent fog. Sometimes they pre- 
sent a deep greenish hue, or are intensely black, or have a purplish, yellowish or 
bluish tinge. When these two masses or banks of clouds, under the impulse of 
opposing currents, approach each other they are thrown into great confusion, 
there is a roaring, likened to the rumbling of distant thunder, and an upward 
expulsion of air and vapor. Soon the funnel of the tornado is let down to the 
earth, and moves to the front, while scuds of clouds play around it. The tornado 
now formed has four characteristic movements : a linear movement toward the 
northeast; a gyratory movement, (north of the equator,) contrary to the hands 
of a watch ; a zigzag or swaying movement which leaves dentated edges in the 
path of the tornado, and a rising and falling movement, the poise of the upper 
current, by which the tornado leaps over portions of its path. 
If one is familiar with these premonitory signs, he is put on his guard, and 
when the tornado appears, he is prepared to act intelligently and promptly. 
Under the preceding principles he can easily determine the projected path of the 
tornado, from the location of the funnel, and whether it will be necessary to run 
north or south to escape from it. He must, of course, not run east or west. 
When a tornado is imminent certain precautions should be observed. Doors 
and windows in houses should be closed, animals in harness unhitched, and 
animals in stables let out. The safest place in a house is the southwest corner 
on the first floor, or better perhaps, the southwest corner in the cellar. If a 
tornado overtakes one on a prairie, lie face downward, head toward the east, and 
place the hands over the head for protection. If near a low solid object, like a 
large stone or stump, He face downward, east of it, head towards the object, with 
hands over the head for protection. 
Every home should have a dug-out at a convenient distance from the house, 
or what is better, a tornado-room built into the west or south wall of the cellar, 
large enough for the family, and for things of great value like deeds or money. 
The destructive effects of tornadoes result from the gyratory movement, which 
is estimated at from one hundred to five hundred miles an hour. Tornadoes 
with the hour-glass form of cloud are the most intense, and seem to be irresistible, 
but the greater number of tornadoes are of a lower intensity and we can build 
against them. Frame houses are more tenacious or elastic than brick or stone, 
and when overthrown are not so destructive to life. They should have strong 
frames. Brick houses should have an extra layer of brick laid in cement in the 
west and south walls. Stone houses with very thick walls laid in cement are 
comparatively safe against most tornadoes. 
Houses built near a hill or a bluff presenting an elevation should be located 
on the northeast side, as the elevation tends to lift the tornado over the house. 
A grove of hard wood, such as oak, maple, walnut and hickory, southwest of a 
house or a forest southwest of a town has a tendency to break the force of a 
tornado and drive it into the upper air, although it is not safe for a person to be 
