A Wine Thief (or as they are known around here, an Eleanor - (latin: Parum furem sororem )) is a means of taking samples of wine or beer for testing for SG values etc. It is a 290mm long plastic tube, open at each end. It is lowered into the wine or beer to be sampled. A finger is put over the exposed end and this enables the sample to be lifted out of the fermenting vessel and lowered into a trial jar. Take your finger off the end and the wine drops out. Its something to do with physics, please don't ask me to explain further as l was probably gazing out of the classroom window when that was covered. But then, it could be magic. Either way, it works and avoids the need for messy syphoning.