Thanks to the _many_ people who responded about Taylor bubbles. So I see how an eruption can take place in a simple tube. But can a sustained (that is, duration of minutes) occur without a chamber of some sort? I cannot see how. Thanks again. Scott Bryan -------------- next part -------------- An HTML attachment was scrubbed... URL: </geyser-list/attachments/20051026/fd1ceb3c/attachment.html>