In a message dated 9/17/2000 10:57:49 AM Eastern Daylight Time,
[log in to unmask] writes:

<< We've heard all about arastras used to break ore-bearing rocks, but what
 about the clay and soil grinding machines that look just like arastras?  I
 don;t recall what they were called, bu I've seen them in various sizes from
 portable to horse powered with 5 foot stones used in preparing materials
 for brick, adobe, and pottery.  Brick bats and pottery wasters could also
 be ground in them and mixed with the clay.

         Dan W. >>

Are you referring to pug mills perhaps?

Carl Steen