164 



HENRY A. HUNT. 



BURSTERS FELT FIRST SOUTH OF SYDNEY. 



The most probable explanation is as follows : — The high pressure 

 following the \ depression in many cases moves faster over 

 Victoria than it does over this Colony, and thus forces the lower 

 part of the y\ to the east making the axis of it more or less 

 towards south-east and north-west. Were it not for this swinging 

 of the y\ depression, the wind, from its natural inclination to the 

 centre of a low pressure, would be south-west instead of due south. 



CONDITIONS GOVERNING THE RATE OF TRANSLATION. 



The southerly isobars of the y\ depression usually reach the 

 south coast first, hence it follows that the burster touches the 

 coastal stations in rotation, beginning at the south. The rate at 

 which it travels in its northerly course is decided, first by the 

 inclination of the axis of the A to the trend of the coast, and 

 secondly, by the then prevailing rate of the general atmospheric 

 motion to the eastward. , 



DIFFICULTY IN FORECASTING TIME OF BURSTER'S ARRIVAL. 



These few remarks will show how many and how serious are the 

 difficulties to be contended with in predicting the moment at 

 which a burst will arrive at any given point, for up to the present 

 moment it has been found impossible to decide how far the axis of 

 the A ma y deviate from its vertical position before reaching the 

 coast, or whether the rate of atmospheric motion may diminish, 

 maintain or increase. 



TABULAR STATEMENT OF THE PROGRESS OF SOUTHERLY 

 BURSTERS UP THE COAST. 





13th November, 



1893. 







Distances 



Interval 



Translatn. 



Stations. 



Time. 





Ratef-hr. 





Miles. 



h. m. 



Miles. 



Moruya 



4 - 45 p.m. 





Velocity of 



Jervis Bay 



5-30 p.m. 47 



45 



62-7 wind at Syd- 



Wollongong 







ney 36 m. in 



Sydney 



7 p.m. 88 



1 30 



58' 7 short gusts. 



Newcastle 



11 a.m. 62 





42 miles. 





16th October, 1893. 





Jervis Bay 



2-30 p.m. 





Velocity of 



Sydney 



9*50 p.m. 88 



7 20 



12 wind at Syd- 



Pt. Macquarie (Oct. 17) 



8-30 a.m. 172 



19 20 



9 ney 20 miles. 





