The difficulty of following the tracks of explorers is acknowledged to be great, especially
where, as in most journeys through the Australian continent, heavy-wheeled vehicles
cannot be employed, and hence the traces of the travellers are with celerity obliterated.
The means of indicating exploring lines have hitherto been limited to marking trees,
and these marks are often passed unobserved in close proximity to the spot by the
most vigilant searcher. It has occurred to the writer of these lines that by sowing
seeds of rapidly growing plants of marked character in many localities during the
progress of an expedition, its lines might be more readily indicated than by any other
method. If, for instance, the seeds of
(the so-called Cape wattle) were chosen for the purpose, the feathery foliage of
the bushy trees would be recognised subsequently at several miles distance as indicative
of the presence of the traveller who selected that particular plant for marking his
route. About 220 seeds of this tree weigh one ounce. Approximately, 100 seeds would
suffice, on an average, to raise here and there, at a distance of a few miles, some
of the plants along one day's exploring march. Hence, less than 10lb. of the seed
would supply to an explorer the means of indicating the lines of his field operations
for fully a year, assuming that 3,000 miles of country are traversed during that time.
If, however, ½ cwt. of such seeds were scattered or planted along the line of a year's
exploration, how many groups of this Acacia might then be established? The soaking
of the seeds in water might always be effected at the nightly bivouacs, and the sowing
be made at almost any spot, since
resists even the most severe drought. It would, moreover, when subsequently sprung
up, in many places afford shady resting-places where now but bare treeless plains
or desert tracts exist. Several other kinds of seeds might be selected for similar
purposes, every explorer choosing his own tree to establish the indications of his
march.
