at Pitt-Town^ New South Wales, 245 



sphere ; and we have not any doubt that, if a continued series 

 of experiments were made at very short intervals in this colony, 

 the hours in averages would be found exactly to correspond. 



Mr John Coldstream made a series of observations, for twenty- 

 four hours, each month in the year, for one year, the results of 

 which were published in the Memoirs of the Wernerian Society for 

 1823. According to the average result of these well conducted 

 experiments, it was ascertained that the daily range of the ther- 

 mometer was on an average about 9°.93, its maximum being 23% 

 which happened in August, its minimum 5° occurring in Fe- 

 bruary. The average daily range would be much greater in 

 this colony, when we know it sometimes ascends from 65° and 

 70° to 114°^ and, according to your own accurate observations 

 at Paramatta, even to 118|° in warm situations in the open air. 

 It would, therefore, be a matter of singular utility, to Jiave 

 many sets of observations long continued, and at very small in- 

 tervals, both at Paramatta and on the Hawkesbury, and perhaps 

 on the Blue Mountains, and at Bathurst or Liverpool Plains, in 

 this colony, that the general rule might be found by which the 

 temperature of the earth is regulated, and changes of tempera- 

 ture produced. This has been recommended by Dr Dewey in 

 America, and by Mr Coldstream in Britain, who very justly 

 observe, " that this is a task that may be accomplished by the 

 co-operation of many, but can never be done by any single in- 

 dividual.'^ If this be the case in America and in Britain, where 

 all " appUances and means to boot'' may be readily procured. 

 It must be greatly increased in this colony, where so little en- 

 couragement, and so few facilities, are given, even by men who 

 profess to love and follow science for the sake of truth, that no 

 man will think of encountering the difficulties. It will be long 

 before an equally accurate set of experiments with your own 

 shall be made we fear in this colony. Should an opportunity 

 present itself to me, I shall not fail to embrace it. Yours, &c. 



