THE STORM OF SEPTEMBER 21, 1888. 257 



Victoria and New South Wales, and in many places very heavy, 

 and it is remarkable that at Bourke and Dubbo the barograms 

 shew a sudden rise, not the rise that is usual with thunderstorms 

 as a precursor of a fall, but a sudden jump upwards in the curve 

 which is carried forward. Something of the same sort appears in 

 the Adelaide barogram for Friday. 



On Friday morning the Sydney weather-chart indicated the 

 same thundery weather which had prevailed for several days. 

 About 1 p.m. distant thunder was first heard at the Observatory, 

 and the storm cloud was apparently much more distant and 

 indistinct than usual when thunder becomes audible. The 

 morning was at Sydney very sultry, there was a good deal of 

 cirrus about which looked like the front of the cyclone, the centre 

 of which was then to south-east of Adelaide. About midday the 

 clouds began to look like a distant storm, and at 3 p.m. thunder 

 was more audible, but still faint as if at a distance ; at 4 p.m. 

 storm cloud was very marked in the south-west, and at 4.25 p.m. 

 the distinctly cyclonic movement of the clouds was observed. 

 The clouds could be seen circulating round the storm from 

 north to south on the east side, and from south to north on 

 the west side, and at the same time rising in the centre 

 and falling suddenly outside. At 4.23 p.m. the wind which had 

 been from east shifted suddenly to south and then south-west, by 

 4.30 p.m. with equal suddenness it went again south-east, and 

 then shifted at one swing of the vane through south-west and 

 and north round to east again, the whole interval for these changes 

 being 25 minutes. At 4.28 the barometer began to rise suddenly, 

 as it usually does for a thunderstorm ; this continued for six 

 minutes, during which time the total rise was 0.030in., and then 

 suddenly that is in one minute it fell 0.044in., which is at the 

 rate of 2.640ins. per hour. I have never before heard of a rate 

 equal to this. Even in the most violent tropical hurricanes it is 

 not nearly so rapid, for instance, in the one that devastated 

 Guadalope on 6th September, 1865, the barometer fell 1.693in. 

 in one hour. A fall of O.lOOin. per hour in Europe or Australia 

 indicates dangerous atmospheric conditions if the fall continue 

 for any length of time, and it is only the short duration of this 

 storm, or in other words its insignificant dimensions, that 

 prevented such intense conditions from giving rise to most serious, 

 consequences ; during just three minutes this sudden depression 

 lasted, and then the barometer rose at the same rate which it fell. 

 Had the instrumental record no confirmation, I should not be 

 disposed to place implicit confidence in it, but I am obliged to 

 believe it exactly true, because in the first place, in the record, 

 such an error is practically impossible, and in the second because 

 there are three other barographs at work in the building. — One, 



Q— October 3, 1888. 



