The a ferrazza (or a ferraccia) method rounded the ends of beads by placing them in a copper pan held over a heat source............

and more:
Posted by: Beadman Post Reply
06/16/2008, 14:44:35
Hi Thomas,
The a speo method is different and separate from hot-tumbling. A speo beads are finished one-at-a-time (or, at best, a few at a time). Tumbled beads are finished en masse—that is thousands (or millions) at a time. These are two different methods to get a similar-looking result. The primary difference is that a speo beads tend to be larger (too large to tumble using the equipment of the time); whereas tumbled beads are generally small (too small and numerous to treat one-at-a-time).

To be really precise, what we now call "hot-tumbling" is only a late variation for a previous technique that the Venetians called "a ferrazza" ("in a pan"). Before a huge barrel-like apparatus was developed for tumbling, that was mechanically turned on an axis (to TUMBLE the beads in a furnace), the device was a pan (that looked something like a big frying pan), in which the beads were stirred. So in earlier times (before the 20th C.), NO beads were "tumbled" (exactly); they were stirred.

In any event, it is a mistake to say 'a speo—sometimes called tumbling.' It is stirred beads that have mistakenly been called tumbled beads. Stirred/tumbled beads should not be confused with a speo beads—because they are very different processes.

All of this is discussed in detail in the article I produced for Beads about a year ago.

Jamey