Leanne:
Happy to hear that you didn't pay for it. When I ran a store I tried to talk people out of buying them, because they are difficult to use, and unreliable. At least, that's my opinion.
That web page has a great write-up on the vinometer. Basically put some wine in the reservoir, let 2-3 drops come through, and turn the vinometer upside down (thus spilling the rest of the wine wherever). Now hold it to the light or whatever in a struggle to read the silly thing.
Btw, I read somewhere that it doesn't work if there is residual sugar in the wine. I found it hard enough to read with red wine, that I never tried white wine.
Steve