That design does not have a cap on the condenser and would be dangerous if it had one.
It's also no longer considered the best design among the hobby distillers and tinkerers who are involved with improving small still design.
You'll probably find a great deal more info on hobby stills, their design and construction on the home distiller forum at http://www.homedistiller.org/forum/ or the artisan distiller forum at http://www.artisan-distiller.net/phpBB3/index.php or the yahoo hobby distiller's group at http://groups.yahoo.com/group/Distillers/ .
The language and practice of even very small scale professional distilling are so different from the hobbyist approach that for someone new to the art, knowledge garnered from either sector will only serve to confuse when applied to the other.
The improved design that you want to go looking for is called "vapor management"
