Given a good hot summer's day, flies as numerous as the supply of water is
scanty, clouds of dust, little or no breeze, and the same quantity of
gold, and a few score of men working within an area of nine or ten acres,
one is sometimes tempted to think that gold may be bought too dear. But
the very lowest depths of despair, cannot compare with the heights of
satisfaction, attained after a successful day's "dry-blowing."
2. BY MEANS OF TWO DISHES, AND A TRIPOD STAND AND PULLEY.
A tripod, twelve or fifteen feet high, is set up over a hard and smooth
piece of ground. By a rope and pulley the full dish is hauled up as far as
required; the rope is then made fast and a string, fixed to the edge of
the dish, is pulled, and the dish tipped up allowing the dirt to fall on
to the prepared surface below, where it is swept up and treated as in the
first method described. With a fair breeze this is a very effectual way of
getting rid of the fine dirt.
3 BY MEANS OF A SIEVE.
This method is only suitable when the soil is wet and sticky, or where the
nuggets are fairly large and not too rare.
On the first rush to Kurnalpi, where more alluvial gold was found in a
short time than on any other field, sieves were almost the only implements
used.
A sieve is very useful for prospecting the surface soil, being more
portable and more rapidly worked than the dishes.
A combination of these three methods is found in the DRY BLOWING MACHINE.
It has always been a hotly debated question, whether what is known as the
"Cement" comes under the heading of "reefs" or "alluvial." This cement is
composed of angular quartz-fragments, broken from the reefs or veins,
and fragments of diorite and hornblende schists, cemented together by
lime; it is very hard and solid and, in places, continues to a depth of
over twenty feet. The gold is extracted from these depths by crushing and
dry-blowing. I have mentioned this peculiar composition last, as I am not
at all clear to which class of formation it belongs.
At first this cement, which the shallow alluvial ground overlies, was
supposed to be "bottom," that is to say, that there was considered no
likelihood of gold being found at a greater depth. Later developments,
however, have proved this theory to be wrong, and with regard to this I
cannot do better than quote extracts from a report made by
Mr. E. P. Pittman, Government Geologist of New South Wales, in which
he says: -
"He had considered the question of deep-leads of alluvial, and after
visiting Coolgardie, Kalgoorlie, and Kanowna, he thought it probable that
there would shortly be a large output of alluvial gold from this source.
In Coolgardie the dry-blowing had been confined to a very shallow depth,
and yet close to Coolgardie - in Rollo's Bore - there was evidence of the
existence of a very deep valley.
