Dear all Hist Arch readers
 
I am seeking comparative information on technologies used in arid gold
field situations to extract gold from alluvial deposits without using
water, especially late 19th century to about WWII.
 
The Australian context is that in the 1890s the first goldfields in the
arid centre were exploited and as water was obviously at a premium a
number of methods were developed to obtain gold from (usually) surface
and buried alluvials.  The first was winnowing with miners' pans, like
chaff is winnowed.  By the 1900s a range of largely ad hoc wheelbarrow
or semi-portable dry blowers were used.  These generally had a shaking
tray with riffles above a bellows system that wouldblow and rework soil
until the heavier gold particles separated.  These were characteristic
throughout arid Australia and 'dryblowing' / 'dryblower' appear to be
Australian coined terms, but there are references to American technology
being investigated  in c. 1895.
 
I am interested in any American (North Central or South..) parallels or
examples.  My suspicion based upon no evidence is that the forms are
indigenous adaptations and will be regionally and individually variant.
Prove me right.
 
Many thanks in advance.
 
Denis Gojak
Historical Archaeologist
New South Wales National Parks and Wildlife Service
Australia