an ore-grinding device whose introduction to the west is attributed to
Spanish/Mexicans.  briefly, it was a circular pad usually enclosed by rock.
in the center was a post with an arm extending out past the rock enclosure
to which an animal was harnessed.  two large rocks were attached to the arm
within the enclosure and the animal was set to walk around the enclosure,
pulling the arm and with it the rocks which dragged and crushed the ore
within the enclosure.

it was very popular for relatively small scale mining enterprises because it
was easy to construct from local materials.  technological developments in
the states led to what was called the "improved" arrastra.  see Historical
Archaeology 17(1):85-95.

-----Original Message-----
From: Iain Stuart <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Thursday, September 14, 2000 3:44 PM
Subject: arrastras


>And arrastras are?????
>
>Iain Stuart
>Principal, Archaeology and Heritage Management
>HLA-Envirosciences Pty. Ltd.