10 AUSTRALIAN WEATHER. 



daily translation of anticyclones in our latitude, over such a large 

 section of the circumference of the globe, holds out a reasonable 

 hope that they may be traced all round, and the proportion of 

 water surface points clearly to the fact that the conditions are 

 more favourable here than in any other part of the earth for 

 normal atmospheric circulation. I do not by this intend to convey 

 the idea that I think an anticyclone keeps its shape, size, form, 

 and pecularities for weeks together, because I see them changing 

 every' day. But nevertheless there are obvious pecularities which 

 affect some anticyclones general characteristics I mean, such as 

 dryness or moisture, which, it may be, are attached to them 

 more persistently than the mere form of the isobars. And if so, 

 it will afford good data for long period forecasting. 



If I have succeeded in showing the normal conditions of our 

 weather, to be that of an endless series of anticyclones passing over 

 to the eastward at the average rate of four hundred miles per day 

 and keeping within a very moderate range of latitude, it will be 

 obvious that these conditions hold out the prospect of our being 

 able to predict the weather for some weeks in advance ; because 

 an anticyclone with such a rate of motion in latitude 38 south 

 would pass round the earth in forty -nine days as stated above. It 

 is true that in isolated anticyclones we find the rate of motion 

 vary considerably over a part of its track ; but I think it is a fair 

 assumption to make, that the average velocity of the anticyclones, 

 in a given latitude, is the rate of progress of the atmosphere at 

 that latitude, and that the apparent variations in rate are 

 simply local accelerations or retardations, which would naturally 

 affect masses of air in motion under several influences, that is, the 

 translation, the constant variations in pressure, temperature, etc. 

 Some of the conclusions arrived at from the examination of four 

 and a half years weather charts, may have to be modified slightly 

 when the investigation is continued over other years ; more 

 especially, when the number of observing stations make the data 

 more complete, but the general agreement of the results in the 

 years examined, seems to support the opinion that there will be 

 no material alterations in the results here given. 



