it by itself offers no sure guide. Very often Albany will report 

 a sudden fall of half an inch in twenty-four bours, while 

 other places will be entirely ignored by the depression. Then 

 again suppose we are satisfied, from a concurrence of reasons, 

 that a storm centre lies to the south of Albany, we have no 

 guide whatever as to what its movements will be. B}^ mapping 

 out the whole of Australia and New Zealand with isobaric 

 lines, as is regularly done every morning, we can perhaps infer 

 to a certain extent that certain particular movements are 

 unlikely. If, for instance, an anticy clonic area, or a region of 

 high barometers, were lying over south-eastern Australia, and 

 another over, or to the west of '^ew Zealand, the normal 

 winter high pressure being over central x4ustralia, while a low 

 pressure was noticed to the south or south-east of the Leeuwin^ 

 we would have fairly good reasons to suppose that the said 

 low pressure would not move eastwards for a time, until some 

 changes had taken place in the conditions over south-eastern 

 Australia and New Zealand. But when no such decided 

 barriers are opposed to a storm's progress, it is not always 

 easy to say in what manner one that is suj^posed to be off the 

 Leeuwin will act. Sometimes it will come steadily eastward, 

 sometimes south-east, sometimes shoot up into the G-reat Bight, 

 and after an indefinite time travel south-east, sometimes south- 

 ward, sometimes remain where it is, and sometimes all trace of 

 it will disappear during the course of a day. 



The most serious difficulty with which we have to contend 

 lies in the fact that almost all the storm centres keep well to 

 the south of the continent. We have thus very often no sure 

 guide as to the distance of this centre, no exact knowledge of 

 the shape of the isobars, even on the northern c^uadrants, none 

 whatever on the southern, and no idea of the state of the 

 atmospheric pressure to the south-east, south, and south-west, 

 to give reasonable grounds for assuming the centre will move 

 in any given direction, or with any given velocity. "When we 

 have managed to satisfy ourselves that a disturbance lies a 

 little south of Eucla, as a general rule we notice that the time 

 of lowest pressure will occur at Adelaide about 20 to 24 hours 

 later, but sometimes the minimum readings occur almost 

 simultaneously at the two stations. There is, however, a very 

 lar^e percentage of storms that once fairly seen to be on their 

 way past Eucla will reach Adelaide in from 12 to 2i hours. 



Another difficulty occurs. Suppose we have noticed a storm 

 centre pass Eucla, after having previously traced it past 

 Albany and Esperance Bay, and have noticed that it is a 

 perfectly steady and business-like storm, proceeding onward 

 composedly and regularly in its work of destructiou or other- 

 wise, and we can be pretty certain that Adelaide will have a 



