162 PHILOSOPHY OF STORMS. 



We invite the special attention of the meteorologist to be 

 directed to this cloud. Let him watch it from the moment 

 of its beginning to form in the morning, taking drawings of 

 it through all its stages ; noting the length of time from one 

 stage to another, until it dissipates or produces rain. If it 

 dissipates without raining let him try to ascertain the cause. 

 Did its top rise into a current of air, moving in a different 

 direction, and preventing it from rising perpendicularly, 

 slicing off its top and dissipating it in air not saturated with 

 vapor? Or did it spread out in all directions, and thus dis- 

 sipate ? Or did the failure depend on the dew point ? Or 

 what were the circumstances in which it differed from col- 

 umnar clouds producing rain ? In case of producing rain, let 

 the top of the cloud be particularly noted. Did it change 

 its appearance about the time, or a little before the rain is 

 seen to descend from its base ? And in case the cloud be- 

 comes very lofty, does the base of the cloud sometimes sink 

 to a lower level, and appear convex below ? And is an ex- 

 tension of this appearance the water spout ? Does the cloud 

 also swell out sometimes above, so as to form a shape some- 

 thing like an hour-glass, or double cone, with the apices 

 together ? What kind of cloud does this columnar or hour- 

 glass rain cloud form after the rain is over, and how does it 

 differ from the cloud which dissipates without raining ? Does 

 it become the feathery cloud, sinking a little at the top and 

 rising at the base, and spreading out in the direction of the 

 upper current ? What is the direction of the upper current 

 at the equator ? Is it towards the west? If so, do storms travel 

 in that direction and with what velocity ? Near the equator, 

 on the north side, do the storms recede a little from the equa- 

 tor as they travel westwardly, and so on the south side of the 

 equator? Or is there any general law on this point ? 



During the rapid formation of the columnar cloud, is the 

 wind affected ? If the theory above alluded to is correct, it 

 'should blow in all directions towards the forming cloud, and 



