METEOROLOGICAL PERIODICITY. 175 



celebrated M. Arago, after a profound investigation of this subject, 

 uses words tliat are well worthy of study, and with them I will 

 close : — 



" Thus the various phcuomena of the celestial vault and of 

 meteorology, even while they appear by their irregularity to 

 defeat the sagacity of the human mind, are ultimately found by 

 profound investigation to be connected by sublime relationship." 



Discussion. 



The HoTf. Johx Smith, M.D., M.L.C., said this interesting con- 

 tribution to the meteorological literature of New South Wales 

 greatly extended the scope of Mr. Kussell's former paper. He 

 deserved great praise for the industry he had shown in hunting 

 up the old records. He (Dr. Smith) had done something of 

 this sort a few years ago for the Water Commission, hunting up 

 notices of the weather in the newspapers, from 1802 down- 

 wards. He believed Mr. Russell had now exhausted all available 

 sources, and they need not look for any additional information 

 of value between the foundation of the Colony and the com- 

 mencement of regular observations in 1840. All they had to do 

 was to study carefully the facts collected. (In proof of the 

 difficulty of getting trustworthy accounts of former years, Dr. 

 Smith compared the statement of Captain Stokes, of the Beagle, 

 as to the drought of 1838-9, with letters kept on record by a 

 friend residing in Sydney. According to Captain Stokes there 

 was no rain at all here for eight or nine months, including the 

 period from November, 1838, to March, 1839 ; but the gentleman 

 referred to mentioned several instances of rainfall in that 

 period.) He (Dr. Smith) concurred in the theory of Mr. 

 Hussell, that we get our rain from the meeting of the cold polar 

 wind with the warm moist equatorial wind (or the return trade 

 wind). The zone of rainfall probably oscillates north and 

 south, according as the polar wind or the equatorial predomi- 

 nates. A comparison of results at Hobart Town or Launceston, 

 Wilson's Promontory, Twofold Bay, Sydney, Port Macquarie, 

 Brisbane, and Bockhampton, would bring out the truth as to this 

 oscillation. Last year Melbourne and Tasmania had more than 

 the usual quantity of rain, while we had less. From this it 

 appeared that either the return trade wind was too strong, or 

 the polar wind was too weak for this Colony. If the fact of 

 oscillation of the rain belt can be established, we should then go 

 a step further and seek to ascertain the cause of the oscillation. 

 The Hon. L. F. De Salis, M.L.C, expressed his opinion of the 

 high importance of Mr. Bussell's paper. He (Mr. De Salis) firmly 

 believed tliat there was periodicity in the weather of the Colony. 

 T 



