May 10, 1858.] WILSON’S JOURNEY IN NORTH-WEST AUSTRALIA. 211 
ferruginous sandstone, originally 300 feet in thickness, but which 
has been largely denuded by the sea, that has drifted its mud to 
lower levels; 2ndly, A compact siliceous sandstone, with hardly a 
trace of stratification, which forms the surface of the many flat-topped 
hills met with in the country ; Srdly, A clay slate, that decomposes 
into a reddish clay and a very productive soil ; and 4thly, Lime- 
stone. The general dip of all these is to the North-West. 
The Plains of Promise, and many other low plains that border 
the sea-coast, are formed of red sandstone, which has been degraded 
by the sea subsequent to its first formation, and has been drifted 
and deposited anew in its present station. Most of the islands in 
the Gulf of Carpentaria are of the same nature. This kind of soil 
is occasionally covered with a productive alluvium, but is poor and 
unfertile in itself. Where the second stratum, the compact sand- 
stone, has been cut through by rivers or by ancient sea action, the 
shale below is deeply worn away, and even now the sides of the 
ravines may be observed to be continually undermined and the hard 
overlying rock breaking off and falling in. In this way are formed 
the extensive plains that run parallel with the dividing ridge and 
the coast,, but separated from the latter by detached masses of 
cliff-topped hills ; their soil consists of a rich and deep clay, through 
which the limestone sometimes protrudes. Trap plains occur in the 
higher part of the table-land. 
Perhaps on no part of the Australian coast are there so many 
rivers navigable to a distance exceeding 50 miles from the sea. Of 
these are the Victoria; the Glenelg, whose mouth is still unknown ; 
the Prince Eegent Eiver, the Adelaide, and the Liverpool. 
The Meteorological Eegister that was kept at the camp on the 
Victoria Eiver, lat. 15° 30' S., gives the following results 
Mean Temperature at 
Max. 
Min. 
Rainy 
Days. 
O 
o 
o 
O 
o 
October 
... 1855 
1 
November 
• • 9 9 
81*0 
100*0 
93-0 
106*0 
69-0 
12 
December 
• • 5 5 
79*0 
94*0 
87-0 
105-0 
73-0 
20 
January 
.. 1856 
78*0 
94-5 
86-0 
104-0 
71-0 
15 
February 
* * 9 9 
78*3 
92-3 
86-5 
99-0 
75*0 
19 
March . . 
79*3 
96-0 
89-5 
102-0 
75-0 
8 
April 
* • 9 9 
75*3 
91*2 
85-3 
98-0 
69-0 
6 
May 
• * 9 9 
66*6 
91 8 
84-7 
96-0 
60*0 
0 
June 
• • 9 9 
59*0 
84*4 
77-5 
97'0 
47*0 
3 
July 
* - * 9 9 
59*0 
87*0 
1 
80*0 
97-0 
49*0 
North Australia is eminently a grassy country, not only from the 
abundance of its grasses, but from their yariety. In no part of 
VOL. II. s 
