Love Barometer

A love meter made of two glass bulbs joined by a narrow tube and partly filled with coloured spirit. Cupping the lower bulb in your hand warms the trapped air, which expands and forces the liquid up the tube into the upper bulb, where it appears to bubble and spurt. In science and physics lessons it demonstrates the relationship between heat, pressure and volume in gases, giving a simple, visual way into gas expansion and pressure differences. An illustrated exercise guide in English is included.