Such an atmosphere, it need hardly be said, is far more enervating than the hot and dry air of the Adelaide plains. The summer, which may be termed warm and dry, usually extends over, say, five months; and during the remainder of the year the climate is simply perfect. The temperature in mid-winter over the Adelaide plains rarely, if ever, reaches the freezing point, although there may be sharp frosts, and on still clear nights, so frequently experienced, copious dews. On the ranges, and on the high lying plains 150 miles north of Adelaide, lower temperatures are reached, indeed in some years there have been falls of snow.
The climatic features of Brisbane are, as a mean expression, decidedly semi-tropical. The months from October to March may be classed as tropic when vegetation makes luxuriant growth, especially if the rainfall prove abundant. The rest of the year, from April to September, is marked by a dry, bracing, "continental" climate, during which the westerly wind often proves very cold, bleaching, and searching accompanied by great dryness accumulated during the passage of this current from southern-central Australia. Many settlers affirm that they feel the peculiar searching character of the dry cold "westerlies" more keenly than the more "honest" frost of the old country. Yet vigorous constitutions thoroughly enjoy the bracing nature of the westerly weather of winter. Hard ground frosts not unfrequently occur in the Darling Downs and Maranoa districts, especially during May, June, and July, in connection with the westerly type of climate; and, moreover, ice has at times been observed in the water-jugs of bedrooms, &c. As before intimated, the westerly winds are marked by great dryness, so that (saturation= 100) a percentage of relative humidity below 33 per cent. may occur during the prevalence of such phenomena, not only in Brisbane, but especially in the more western districts above mentioned. Such conditions are characterized by great diathermancy of atmosphere, and hence are frequently followed by days of considerable heat. Even in the tropics, in inland districts, ground frosts are known to have occurred owing to this extreme diathermancy of the atmosphere far from the coast, and the consequent attendant factor of active terrestrial radiation. In coast districts, or that fringe of country bordering the ocean north from Rockhampton, frost is of very rare occurrence, and the prevailing winds are between south-east and east-north-east, with a rainfall far more abundant than that obtaining in other parts of Queensland. The climate of the country surrounding the southern end of the Gulf of Carpentaria is very hot and trying from November to March, but genial thenceforward. It is certainly not unhealthy, and the fevers suffered from in the northern and gulf districts of Queensland are largely brought on by reckless or needless exposure.
In addition to the foregoing, which has been obtained from head-quarters, certain questions were submitted by me as to the climatology of the different colonies. As it will be seen, these interrogations are somewhat extensive in their scope, and supply knowledge upon points, which is not ordinarily met with in my descriptions of Australian climate. In drafting them everything which had a bearing on health was included as far as possible, and consequently in a work of this kind they unquestionably deserve a prominent place. In arranging them I purpose placing the different replies after each question in the following order, namely, New South Wales, Victoria, South Australia, and Queensland. And in the different answers it should be borne in mind that Mr. H.C. Russell is responsible for New South Wales; Mr. R.L.J. Ellery for Victoria; Sir Charles Todd for South Australia; and Mr. Clement L. Wragge for Queensland.
IS IT NOT A FACT THAT THE TEMPERATURE AND BAROMETRIC PRESSURE ARE EXPOSED TO SUDDEN AND MARKED CHANGES? HAVE YOU KNOWN THE TEMPERATURE TO FALL, SAY, AS MUCH AS 22 DEGREES IN 15 MINUTES?
New South Wales.--The temperature sometimes changes rapidly in the summer, coming with a change from a hot wind to a cold southerly, although the instances are rare.