140 On Dust Whirlwinds and Cyclones. [No. 2. 



On Dust Whirlwinds and Cyclones. By P. F. H. Baddely, Esq. 

 M.D. ; B. Artv. Lahore. 



*' Who holds the furious storms in straighten'd reins, 

 And bids fierce Whirlwinds wheel his rapid car ?" 



Young. 



During February and March, 1851, while engaged in the inves- 

 tigation of Dust Whirlwinds, I twice witnessed a curious fact, which 

 seems to throw considerable light upon the complicated phenomena 

 of Storms. 



In following up on horseback a dust whirlwind, I observed that 

 as it passed various objects in its progress, such as tents, horses, &c. 

 it gradually diminished in size, till at length instead of a whirling cir- 

 cle of 5 or 6 feet in diameter, composed of several rotating cones or 

 spirals of dust, Plate 2, it terminated in a single cone, the apex of 

 which in contact with the earth, rotated briskly like a top, from left 

 to right, as did the whirling circle before, of which this was a portion. 



From the cone of dust, a long ribband-like band about 12 inches in 

 diameter, of equal dimensions throughout, as far as the eye could 

 reach, was seen to extend into the atmosphere, and from the circum- 

 stance of its sides presenting a greater opacity than the central por- 

 tion, I concluded it was cylindrical. 



This band was rendered faintly visible by the dust it had whirled 

 up, which by the light of the sun that shone through it, exhibited a 

 kind of vermicular spiral motion. At about 50 or 60 feet above the 

 surface of the ground, the band formed a distinct coil, as represented 

 in the plate, still preserving its cylindrical appearance, and extending 

 upwards and forwards in advance of the whirling cone, Plate I, Fig. 1 . 



Suddenly the Cone, which had the last continued to rotate, vanished 

 from the earth, and the whole band then slowly receded upwards and 

 onwards out of sight. 



The common dust whirlwind, is I conceive, a miniature representa- 

 tion of a Cyclone, and this band seems to indicate the ultimate thread 

 of the electrical spiral mass of which the whirlwinds are composed- 

 Whirlwinds large and small, appear to be made up of a number of 



