3S2 



Colonel field's Tfoiu on 67 o ;•/,'/ ,v : 



[ A rail- 



Now the continuotl oi'cunoncc of phenoiveivi lliis naluro, militufes 

 against the thoory, (h it stoniis are piogn ssiv i< w lii. Iwiiuls," or rntlirr 

 — as I li;\vo obsorvoil bo(\)ro — loaves !ho tlimry inoiunplclo ; for, we 

 sho.ild naturally expert from a wlurlwiiui, that, its sociioiial outline 

 wouUl bo circular, and, that the time Dccupied bolvvoon llio coinnionce- 

 mont and niiddlo, would oorrospond willi ih.if ohsiM'vod botwoon ilio mid- 

 dle and termination, whereas weluivojust founil them to stantl in the 

 proportion of *JJ to 1. In other respeois too, iho theory adopted by Co- 

 lonel Reid hasnot met willi oomplelo eonlirmaliuii, as will bo soon with 

 roferoneo to particulars observed in the ^h^(iras sI'Uim of ib3G: it appears 

 from the little information I was then able to obtain, that the centre of 

 this storm passed over a ship (theWatcr \Vit( h),at a distance of 7^0 miles 

 ^o the eastward of Madras, at i past 7 o'elockon the evening of tlie 29th 

 Oolober— just 24 hours befuro it rfacbod Madras; exhibitinii; a velocity 

 of prt)gro>sion of .'■$2 miles per huur: hence, wliatover niay have been 

 the rotatory velocity of any jM)iiii such as a fi<r. 3 (call it j'), it follows, 

 that, .it some plaoe {!>) to the norlliUrird (d' Madras, a linrricajio of the 

 vclocit-y .r \- 32 miles per hour must have been experienced ; whereas at 

 a corre«:pon liui]^ place (r) to the southward, a velocity x — ?>2 miles ])er 

 hour only would have been experienced ; ()r,since x n^prcsonts the velocity 

 which woultl be experienced at Madras, it would appear, that the gale 

 must have been 61 miles perhourmoro rapid — stronger — to the northward 

 of Madras than it was to the southward: whereas, from enquiries made 

 at the time, it appeared that a trifling dilTerenee only was experienced. 

 With this view of the subject, it will, perhaps, eventually be found ne- 

 cessary to admit, that the onward progressicjn of storms is propagated 

 by undulotion.9, and not by an actual movement of the particles compos- 

 ing the whirlwind : — and, further, with reference to fig. 3 — if the smaller 

 circle d e, represent the space within which the air was quiescent, the 

 theory would lead us to suppose that at and e a similar sfrength of 

 wind would be experienced; whereas, in the storm of 1836, as well as 

 that of 1813, and indeed in every storm wliich has occurred at Madras, 

 the wind experienced after the lull, is far more violent than that which 

 preceded it. 



In conclusion, I may say for myself, that I have been led to make 

 these remarks, not with a view of finding fault with Colonel Reid's 

 book or his theory, but with an earnest desire of forwarding, to the best 

 of my abilities, what he has so ably commenced. 



Madras Observatory : > 

 Ut June, 1839. > 



