SCHAW. — Australasian Weather-charts and N.Z. Storms. 63 



indebted for the initiation of this system of weather observa- 

 tions and weather-charts, although it so happens that the 

 Governments of Queensland and South Australia, and more 

 especially the former, have been most wisely liberal in provid- 

 ing suflicient funds for maintaining an efficient meteorological 

 department of State. 



Before proceeding to discuss these weather-charts, how- 

 ever, I wish to draw your attention, first, to the schematic 

 representation of the general circulation of the atmosphere 

 given in the diagram (PI. V.), and to the general theory of cy- 

 clones and anti-cyclones, premising that on both subjects we 

 are far from having attained to accurate knowledge, or to a 

 general consensus of opinion. 



Starting at the equatorial belt of calms, which, you will 

 observe, lies north of the equator, we see the upper current 

 flowing over towards the poles, while a cooler under current 

 in the opposite direction flows towards the equator to replace 

 the other. This cool current, deflected to the left, as before 

 mentioned, causes the south-east trade winds in this hemi- 

 sphere. 



At about 35° latitude the upper current flowing pole-wards 

 is met by an opposite upper current flowing towards the 

 equator, and in this region lies the belt of comparative calms 

 and high pressure with anti-cyclonic circulation (i.e., against 

 the hands of a watch in this hemisphere), and the currents re- 

 appear near the surface of the earth, flowing out from the calm 

 belt north and south. That flowing north, in this hemisphere, 

 or towards the equator, we have already noticed as the south- 

 east trade winds ; that flowing towards the southern pole, de- 

 flected to the left or eastwards, produces the " brave west 

 winds," " the roaring forties," or the " counter-trades " so well 

 known to navigators. In the higher atmosphere above these 

 westerly winds a reverse current exists flowing northwards to- 

 wards the equator : and here our fairly-certain knowledge ends ; 

 but there are strong grounds for believing that the general circu- 

 lation is completed as shown in the diagram, an upward circula- 

 tion taking place at about the 60th parallel of latitude, with a 

 very low barometer when the opposing low-level currents meet, 

 just as the downw^ard circulation with a very high barometer 

 occurs at the meeting-place of the high-level currents near the 

 35th parallel of latitude. Beyond this is pure conjecture at 

 present ; but reason leads us to believe that the high currents 

 from all sides meet in the region of the pole, causing anti- 

 cyclonic calms and high pressure there, and a vigorous outflow 

 on all sides at a low level. This appears to be the vertical or 

 meridional system of general circulation. 



As regards the two contrary and apparently supplementary 

 systems of circulation in a horizontal, or, rather, gyratory, 



