Thanks, Alan! Now I can see it! And you're right, there's not much wire at all that gets immersed. Just out of curiosity, have you (or has anyone) compared measurements using your system vs. the water displacement one using the same 'weights? It would be interesting to know whether there are consistent differences in the two ways of finding density if two systems are commonly being used to measure them.
Oh, re: the stocking question...just saw this again from Kev's post, "If an absorbant material is used, such as with some types of "net bags", then it is possible that enough water can be absorbed up the material such that the weight of the material outside the main water compromises the calcualtions." That's another good point, the capillary action of whatever's used to hold the things. The few strands of wire definitely seems a better option!
I wonder how much altitude affects measurements of a weight in water. Would someone in Denver get the same reading as someone in Denmark?
(Yes, I'm a frustrated scientist, inflicting myself on the GMB.)