176 REMARKS ON THE PRECEDING PAPER, 



A heavy thunderstorm from S.W. is always preceded by a 

 N.E. wind, and if such a wind in summer blows fresh after sun- 

 down, in 9 times out of 10 the next day will exhibit thunder. 



So, preceding the gales of 6th and 9th August, 1861, 1 noticed 

 the upper clouds progressing from the westward, and the surface 

 wind from westward also, when, quietly at first, a body of 

 clouds which had formed in the east began to move westwardly, 

 and the east wind wedged itself in between the two westerly 

 strata, and after a struggle of about 3 hours obtained the mastery. 



A similar phenomenon was observed by me before the cyclone 

 of ll-12th June last, and that of June, 1857. So constant 

 is the struggle between the polar and equatorial winds, that I 

 have never missed it when I have looked for it, at the commence- 

 ment and close of a hot wind. The hot wind frequently com- 

 mences at Sydney from seaward at N.E., and ends at S.W. or S. ; 

 clouds, for hours preceding the change, gathering in S.W. by 

 condensation of the vapour suspended by the N.W. wind through 

 the contact with the S. wind. The KB. wind hot is the hot N.W. 

 current deflected by the KB. 



Furthermore, I have stood out in a furious hot wind for hours 

 watching the wind vane, which is then oscillating between S.W. 

 and N.W. ; and if any one will but place an aneroid on his table, 

 under his eye, during one of our summer thunderstorms, he will 

 observe the index oscillating to and fro, as the pressures occasioned 

 by the two winds engaged in conflict alter according as they gain 

 or lose strength by turns. 



Taking then all these facts into consideration, I consider it 

 demonstrated that there are always two winds engaged in all our 

 storms. 



Now, to utilise the observations we have by forecasting coming 

 storms, seems to be the object of Mr. Tebbutt's paper. I agree 

 with him, that to do this we must have more observers, and 

 perhaps more correct ones than we have at present. 



Many of the published notes in the daily papers are useless, 

 from occasional typographical errors, and errors of observation. 

 I have been in the habit of checking the figures given by the 

 observers, which, when the heights of the places of observation 

 are known, is the easiest -thing possible. If the readings are 



