Pig ay it 
W. Ferrel—Cyclones, Tornadoes and Waterspouts. 33 
Art. VII.—Meteorological Researches, Part bie ee ak Torna- 
: does and Waterspouts ; by Wo. F 
[Abstract, published by permission of CarLILE P. PaTrerson, Superintendent 
of the United States Coast and Geodetic Survey. ] 
torial and ae regions. This gives rise to an interchanging 
motion of the air, toward the equator below and from it above, 
and if it were not for the effect of the earth’s rotation on its axis 
this interchanging motion would be at all places in the direc- 
tion of the meridian, and would be continually accelerated in 
its initial motions, until the friction arising from these motions 
would exactly equal the force producing them, after which the 
motions of any one place would be constant, but of course differ- 
ent at different places. The now well- known effect of the 
earth’s rotation is to give rise to a deflecting force to the right 
of the direction of the moving body in the northern hemisphere 
and the iebanlle in the southern, whatever may be the direc-— 
_ tion of motion, Hence the air in moving above toward the 
poles, is deflected toward the east and in moving toward the 
equator below, toward the west, so that the tendency is for the 
air to assume an eastward motion in the middle and higher lati- 
tudes, and a westward motion nearer the equator. ‘These latter 
motions combined with the interchanging motions between the 
equatorial and polar pao give rise to what. are called the 
_ general motions of the atmosphere, depending upon the differ- 
ence of temperature between these regions and independent of 
local disturbances of temperature. 
The amount of eastward motion depends upon the amount of 
_ friction, and must be such that the friction at the earth’s sur- 
| face is equal to the force causing this component of motion, 
_ and the same with regard to the westward motions. According 
. a well established principles of Nashanie there cannot arise 
_ any force from the effect of the earth’s rotation, which by means 
of friction would tend to either increase 2 decrease the earth’s 
SPs ART ee 
* Coast and Geodetic Survey Report for 1878. Appendix 10. 
Am. Jour, re Serizs, Vou. XXII, No. 127.—Juxy, 1881. 
