178 HENRY A. HUNT. 



It also appears that the hour of maximum varies from year to 

 year, in 1891 it was from 9 to 10 ; 1888, 11 p.m. to midnight; 

 1875, 1 to 2 p.m. and so on. 



The questions as to the number and strength of bursters in the 

 several seasons and months of the year I have treated in the same 

 manner. 



TABLE II. 



In Table No. 2, all the bursters on record have been grouped 

 in another way, which brings into evidence other characteristics. 

 The table has the years on the sides and months across the top, 

 and the information given under each month and for each year is 

 the maximum velocity of the wind, and if there are several bursters 

 in the month the average of their greatest velocities ; at the right 

 hand side the average of the greatest velocities for the year, and 

 the greatest velocity attained at any time during the year. It is 

 also shown that the average number in each year is thirty-two, 

 the greatest in any year fifty-six, and the least sixteen. The 

 average of all the greatest velocities is 42*7 miles per hour, the 

 greatest one hundred and fifty-three miles per hour. (It must be 

 borne in mind that all the anemometer results at Sydney are 

 recorded on the assumption that the velocity of the wind is three 

 times that of the centres of the cup, this has been the practice 

 since 1862, and it is deemed better not to alter it until the exact 

 ratio has been decided and generally accepted.) 



It is necessary to state here that in the conditions under which 

 this prize essay was written, there is no express definition of the 

 minimum velocity of wind which shall constitute a burster, I have 

 therefore taken as such every sudden shift of wind to south or 

 south-west, from any point between west and north on the one 

 side and east and north on the other side, irrespective of the 

 velocity of the wind ; always provided however, that the velocity 

 was maintained subsequently for some hours with force. 



It will be observed that the table brings to light the fact, that 

 the mean velocity of the wind is greater in spring than in autumn, 



