Rev. J. Macgarvic's Tkermomeirkal Observations. 235 



governoi*, that any thing I can say on the subject may appear 

 like a tale twice told. But yoicr observations were made at Pa- 

 ramatta, 7nine were made on the Hawkesbury, twenty miles far- 

 ther in the interior, in full view of the Blue Mountains, and sub- 

 ject to dense fogs in the morning, and scorching heats at mid- 

 day, from an almost vertical sun and hot winds. 



The general average of the days, in this part of the colony, 

 may be stated as follows, the varieties being very limited. In 

 some, the morning sets in with a dense fog, which disperses 

 about ten, or sometimes sooner, and ushers in a hot day. Other 

 days arc clear in the morning, and cold at mid-day, by reason of 

 a strong cool breeze. Other days commence with a dark-blue 

 haze setting in over the forest, which continues for some time, 

 and is always followed by great heat in the sun's rays. , Other 

 days are remarkable for commencing with a clear sky in the 

 morning, which increases to a hot clear noon, with a close, sul- 

 try, suffocating, warm wind, during the rest of the day. This 

 is that sort of wind prevalent on the south side of the Equator, 

 near the Cape of Good Hope, which seamen call a fiery south- 

 easter. Other days are completely enveloped in clouds, when 

 the thermometer ranges very little all day. Other days are re- 

 markable for incessant rain. These varieties are so common in 

 the colony, that it is no difficult matter to predict the kind of 

 day from the*appearance of the morning. Occasional deviations 

 sometimes take place ; as in the case of occasional dry squalls, 

 and thunder storms, which are very loud and long-continued ; 

 but these are exceptions to the general rule. 



The extremes of this division, the very hot days, on which 

 the thermometer r>anges from 30" to 40°, and the calm moderate 

 days, on which it ranges from 3° to 4°, were so unlike the same 

 days in England, that I considered it might be useful to know 

 the fluctuations of the thermometer upon these days, to see if 

 Uiey might assist in forming or explaining some general rule that 

 might account for the distribution of heat, and change of tem- 

 perature. 



As I have neither time nor inclination to indulge in lengthened 

 speculation on the subject, I shall give you the results of my ob- 

 servations, made with great care, from which you will sec that 

 the thermometer, on these hot days, fluctuates in a most surpris- 



