INTRODUCTION. xxx j 



range is from 50 to 98. The winds show a reversed order at these 

 two places : while it blows from the eastward on the east coast during 

 the summer season, it is blowing from southwest on the south coast ; 

 and in the winter this is again reversed to southwest at the former 

 place, while at the latter easterly winds are experienced; the cause 

 of this state of things is to be looked for in the extensive arid wastes 

 which exist in the centre of New Holland, and will account for 

 some of the remarkable phenomena which take place in the climate ; 

 perhaps there is none more notable than the excessive droughts which 

 frequently prevail and continue for months ; in other years great 

 floods occur. In the Narrative, Vol. II., p. 168, 4to. edition, I have 

 spoken of the exploration of the country, and the peculiar condition 

 in which it was found by the exploring parties, and to which I would 

 refer for information upon the subject. The quantity of rain which 

 falls is very variable : in 1840, 35-25 inches fell; in 1841, 45 inches; 

 making a fourth more. The rainy season is in April and May : the 

 greatest quantity which has been 'known to fall in any one day, was 

 20-12 inches. 



The degree of moisture, by our observations, was -748. I have 

 before remarked that there is a great difference in the climate of New 

 South Wales, and that every locality has in a measure its own. It is 

 difficult to account for the anomalies that occur in the seasons. The 

 rains that prevail on the eastern coast, are generally brought by the 

 west and southwest winds from the interior, as all the meteorological 

 registers, kept at Port Jackson and Macquarie, prove : these are land 

 winds; yet, at an opposite season, we find these same winds causing 

 the blight that is so much dreaded by the agriculturist, from the want 

 of moisture. In March, the barometer stood at 29-969 in., while the 

 temperature of the air and water had risen from 3 to 4 higher than 

 in December. 



ANTARCTIC CRUISE. This cruise was made during the summer 

 season of the southern hemisphere. The diagram on Plate XL, p. 302, 

 gives the track of the Vincennes, the oscillation of the barometer, 

 and the variations of the thermometer, the mean daily depression of 

 the barometer, or the diminished pressure of the atmosphere within 

 and along the Antarctic continent : the mean pressure was deter- 

 mined to be 29 - 040 in., its extreme oscillation 1-160 in. The tempe- 

 rature of the air, with but few exceptions, followed that of the 

 water : these exceptions only took place when near large bodies of 

 ice, and Avhich are readily distinguishable on an inspection of the 

 diagram. During a period of 42 days in midsummer, the tempe- 



