504 



General Notices. 



rise marked 20°, 19°, 18°, 17°, 16°, 12°, aad, on two separate days, even 

 11° ! On the 22d of May, the river ivas frozen, and yet herbage was luxu- 

 riant, and the country produced Nimosas, Eucalypti, Acacias, the tropical 

 Bottletree (Delabechea), a Calandrinia, and even a Loranth. On the 23d 

 of May, the thermometer at sunrise marking- 12°, Acacia conferta was com- 

 ing into flower ; and Eucalypti, with the usual Australian vegetation, were 

 abundant. On the 30th of May, at the elevation of 1118 feet, the almost 

 tropical Delabechea was found growing with the temperature at sunrise 22° 

 and at 9 p. m. 31°, so that it must have been exposed to a night's frost grad- 

 ually increasing through 12°. And this was evidently the rule during the 

 months of May, June, and July, (our November, December, and January) ; 

 in latitude 2G° S., among Tristanias, Phebaliums, Zamias, Hoveas, Myopo- 

 rums, and Acacias, the evening temperature was observed to be 29°, 22°, 

 37°, 29°, 25°, falling during the night to 26°, 21°, 12°, 14°, 20° ; in lati- 

 tude 25° S., the tents were frozen into boards at the elevation of 1421 feet, 

 the thermometer, July 5, sunk during the night from 38° to 16°, and there 

 grew Cryptandras, Acacias, Bursarias, Boronias, Stenochiles, and the like. 

 Cymbidium canaliculatum, the only Orchidaceous epiphyte observed, was 

 in flower under a night temperature of 33° and 34° ; that by day not exceed- 

 ing 86°. These facts throw quite a new light upon the nature of Austra- 

 lian vegetation. It may be supposed that so low a temperature must have 

 been accompanied by extreme dryness, and such appears to have been 

 usually the case. Nevertheless, it cannot have been always so, for, although 

 we have no hygrometrical observations for June and July, and only four 

 for May, yet there is other evidence to show that the dryness cannot always 

 have been remarkable. In May, the hygrometer indicated •764, -703, -934, 

 or nearly saturation, and "596 ; yet the sunrise temperature was on those 

 occasions 25°, 28°, 30°, and 34°. On the 22d of May, the grass was white 

 with hoar frost, and then the thermometer was, at sunrise, 20° under canvas, 

 and 12° in the open air ; and, on the 5th of July, when it rained all day, and 

 the tents were ' frozen into boards,' the thermometer sank during the 

 night from 38° to 16°. It is probable that this power of resisting cold is 

 connected with the very high temperature to which Australian vegetation is 

 exposed at certain seasons, and this is horiiculturally a most important con- 

 sideration. We find that, in latitude 32° S., in January, (our July,) the 

 thermometer stood eight days successively above 100°, and even reached 

 115° at noon ; that it was even as high as 112° at 4 p. m. ; that in the lat- 

 ter part of February, one degree nearer the line, it was twice 105° and once 

 110° ; that in March, one degree further northward, it frequently exceeded 

 100°, and there was not much fall in this excessive temperature, up to the 

 end of April. This will be more evident from the following 

 Table of Noon-day Temperatures. 



L atitude 



29° S. 

 32 S. 

 31 S. 



30 S. 



Nov., Dec 



Jan. Feb 



Feb., March... 

 March. 



Average of 3 Observ., 102° 

 IS .., 97i 

 17 „ 90 

 20 ,, 95 



Max. 



Min. 



