a 
Petermarn Creek, after a nearly easterly course of about forty-five miles, 
joins the Palmer at ten or twelve miles below the Walker junction. From the 
Petermann junction the Finke pursues a nearly E.S.E. course for sixty miles, 
when it is joined by a very important branch, the Hugh. This river has its 
‘source on the northern edge of the Macdonnell Ranges, about twenty-five miles 
west of Alice Springs, and, sweeping through the range at Brinkley Bluff, flows 
in a general E.S.E. direction. ‘The Finke is next joined on the west by the 
Lilla at a point thirty-two miles in a direct line 8.S.E. from the Hugh junction. 
About thirty-six miles in a direct S8.E. line.from the last point another creek, 
the Goyder, joins the Finke on the west. Further south still, and to the east 
of Charlotte Waters, it is jomed by the Coglin. 
Below the junction of this creek the Finke has no defined channel, but 
spreads out over wide alluvial flats. Sixteen miles 8.S.E. of Charlotte Waters 
the telegraph line crosses Adminga Creek, which runs easterly to the flats over 
which the Finke waters spread. Still further to the south the Alberga, which 
takes its rise in the eastern extremity of the Musgrave Range, after being joined 
on the nerth by a tributary, the Stevenson, and being then known as tlie 
Macumba, flows E.S.E. towards Lake Eyre. It is into the Macumba that part 
of the floodwaters of the Finke flow on their way to Lake EHyre. The greater 
portion, however, disappears from the surface, and is absorbed by the vastly 
extensive sandhills and plains which stretch round the north and east sides of 
Lake Eyre. In the above description of the Finke and such of its tributaries 
as occur in the area examined by the Expedition no mention has been made of 
the Todd, an important stream which takes its rise on the northern edge of the 
Macdonnell Ranges to the north of Alice Springs. It leaves these ranges at 
Heavitree Gap, and at first has for many miles an easterly course, after which 
it turns 8.S.E. towards Lake Eyre. It is very probable, but this is not 
certainly known, that the Todd junctions with the Finke south of Charlotte 
Waters. 
(6) Length and Rate of Fall of Finke Channel.—The total length of the Finke 
from its source in the Macdonnell Ranges to Lake Eyre must be about 1,000 
miles, although the distance in a direct line is not greater than 500 miles. A 
few calculations have been made on the rate of fall of the channel of the Finke 
over different portions of its course. The difference in the altitudes above sea 
level of the channel of the Finke at Mount Sonder and at the Mission Station, 
a distance of fifty-four miles, is about 490ft. These data give a rate of fall of 
about 9{t. per mile. Between the Mission Station and the junction of the 
Palmer with the Finke the rate of fall is 5ft. per mile, the difference in the 
altitude of the two places being 699ft., and the distance between them 135 
miles. Lastly, the difference in the altitudes of the Finke Channel at the 
Palmer junction and at Lake Eyre, a distance of 536 miles, is 980ft., which 
gives a mean rate of fall of less than 2ft. per mile. Between Heavitree Gap 
(1,718ft. above sea level) and Oodnadatta (397ft. above sea level), a total 
distance in a direct line of 357 miles, the fall of the slope of the surface 
averages about 3°7ft. per mile. 
The above figures show, as might have been expected, that the rate of fall is 
at its maximum in the Macdonnell Ranges, and at a minimum on the Cretaceous 
plains near Lake Eyre, between which places there is a gradual decrease in the 
rate of fall as we go from north to south. 
