The oscillatory motion was imparted to this by one tentacle of the
handling-machine.  With two spatulate hands the handling-machine was
digging out and flinging masses of clay into the pear-shaped
receptacle above, while with another arm it periodically opened a door
and removed rusty and blackened clinkers from the middle part of the
machine.  Another steely tentacle directed the powder from the basin
along a ribbed channel towards some receiver that was hidden from me
by the mound of bluish dust.  From this unseen receiver a little
thread of green smoke rose vertically into the quiet air.  As I looked,
the handling-machine, with a faint and musical clinking, extended,
telescopic fashion, a tentacle that had been a moment before a mere
blunt projection, until its end was hidden behind the mound of clay.
In another second it had lifted a bar of white aluminium into sight,
untarnished as yet, and shining dazzlingly, and deposited it in a
growing stack of bars that stood at the side of the pit.  Between
sunset and starlight this dexterous machine must have made more than a
hundred such bars out of the crude clay, and the mound of bluish dust
rose steadily until it topped the side of the pit.