A most attractive English Derbyshire black marble and Pietra Dura desk thermometer in the form of an obelisk. Decorated and inlaid with flwers and leaves in various types of marble. Set upon a stepped base. The thermometer in Farenheight and centigrade. England circa 1840.15 inches high by 5.5 inches wide by 3.75 inches deep ( 37.5 cms by 13.75 cms by 9.375 cms).