subject of scientific speculation. North and north-west of Flinders Range
are large plains covered with stones, extending as far as latitude 25
degrees. To the north of that, although the sun was intensely hot, there
were no hot winds; in fact from that parallel of latitude to the Indian
Ocean, either going or returning, they were not met with. "On reaching
latitude 27 degrees on my return," writes Mr. Stuart, "I found the hot
winds prevailing again as on my outward journey. I saw no sandy desert to
which these hot winds have been attributed, but, on lifting some of the
stones that were lying on the surface,* I found them so hot that I was
obliged to drop them immediately. (* On the surface, as I suppose, of the
large plains North of Flinders Range. ED.) It is my opinion that when a
north wind blows across those stone-covered plains, it collects the heat
from them, and the air, becoming rarified, is driven on southwards with
increased vehemence. To the north of latitude 25 degrees, although
exposure to the sun in the middle of the day was very oppressive, yet the
moment we got under the shade of a tree we felt quite alive again; there
was none of that languid feeling which is experienced in the south during
a hot wind, as for example that which blew on the morning after reaching
the Hamilton,* in latitude 26 degrees 40 minutes. (* Journal 1861 to
1862.) That was one of the hottest winds I ever experienced. I had the
horses brought up at 7 o'clock, intending to proceed, but seeing there
was a very hot wind coming on, I had them turned out again. It was well I
did so, for before 10 o'clock all the horses were in small groups under
the trees, and the men lying under the shade of blankets unable to do
anything, so overpowering was the heat." Unfortunately, Mr. Stuart had no
thermometer.

Mr. Stuart is anxious to direct attention to the establishment of a
Telegraph line along his route. On this subject he writes as follows:--