glas[br]water[br]paper clip[br][br]
1 Fill a glass with water.[br][br]2 Carefully top the water up until the glass is full. Keep adding water and observe that the water does not overflow but starts building a bulge.[br][br]3 Take a paper-clip and carefully slide it onto the water.[br][br]4 What happens next? Paper-clip (1) swims/ (2) sinks[br]