Round-bottomed glass eudiometer built in the late eighteenth century on the model designed by Alessandro Volta. The top end carries a small hollow brass cylinder with slits and three radiating pointed rods. A glass cylinder is attached to the brass cylinder. A swiveling brass ring is fastened to to the top. The instrument, signed "G. Adams London," is the work of the famous English naturalist and instrument-maker George Adams. The eudiometer was used to measure the quantity of carbon dioxide in atmospheric air within a confined space.