CIRCULATION OF THE ATMOSPHERE 



449 



or less illustrated in nature, but he never succeeded in uniting the three 

 equations in one comprehensive system. The Germans approached more 

 nearly a satisfactory solution, but as already stated, the assumption that 

 cyclones and anticyclones are symmetrical, respectively, about warm and 

 cold centers, is no longer tenable. We have already made the assertion 

 that the asymmetrical cyclone, as it occurs in nature, does not conform 

 satisfactorily to any homogeneous vortex. It will be possible to show 

 how this is by giving a few details regarding waterspouts, tornadoes 

 and hurricanes, which will lead up to this conclusion. 



Local Vortices in the Earth's Atmosphere 



A large waterspout was seen at Cottage City, Mass., in the Vineyard 

 Sound, on August 19, 1896, about eight miles distant from Cottage 

 City. Fortunately a series of good photographs was secured of the 

 waterspout and its cloud, which together with the meteorological data, 

 have enabled us to compute the dimensions and the velocities of motion 

 in all parts of it by means of the vortex formulas. It happens that the 

 same cloud developed two types of vortex, at short intervals of time 

 between them. One is the funnel-shaped vortex and the other is the 

 dumbbell-shaped vortex. Fig. 1 gives an illustration of a section 



Fig. 1. Funnel-shaped Vortex. 



through the funnel-shaped vortex, and shows the boundary of the sev- 

 eral vortex tubes. The horizontal dimensions are multiplied by ten 

 for the sake of showing the relative dimensions more plainly which 

 exist from one tube to another. It will be noted that the distances 

 between the successive tubes get smaller and smaller in a geometric 

 ratio towards the axis. They concentrate at the lower part, and expand 

 so that the lines become parallel to a horizontal plane in a region at 

 vol. lxxvi. — 31. 



