W. Ferrel— Cyclones, Tornadoes and Waterspouts. 37 
it cools at the rate of 1° C. for each 100 meters before it 
conditions of a continuing cyclone at all, the power of the 
cyclone would at least be very w 
ere the state of the atmosphere is such, whether dry or 
saturated with moisture, that the rate of decrease of tempera- 
ture with increase of altitude is greater than in an ascending 
current, it is ee to be in a state of unstable equilibrium, since 
ing action of the currents set in motion. But an pera 9 
in this state over a large area would not furnish the conditions 
for a large cyclone, but there would be simply a bursting up 
of the lower strata through the upper ones at various places, 
giving rise to numerous local showers, and often to tornadoes 
and hailstorms. In order to have the complete conditions of a 
rtant element, since without this we cannot have the state 
«2 unstable equilibriam unless the rate of decrease of tempe- 
rature with increase of elevation in the atmosphere generally 
is greater than 1° C. for each 100 meters, but where the air is 
saturated this condition takes place with a rate of decrease less 
than half as great, : rate of decrease which is often found in 
vapor, and the “ab sae the decrease of temperature of the air 
ith the increase of elevation, the greater is me 
power of ag clone. But without these there sid be: 
small gradients with no violent winds, and the depression only 
becomes 2 from the gradients extending over a large 
e equator where there i is no gyration of the area of 
alain: around its center in virtue of the earth’s rotation 
