DEWAR VESSEL n.
el for holding liquid air, etc., having the space between the walls exhausted so as to prevent conduction of heat, and sometimes having the glass silvered to prevent absorption of radiant heat; -- called also, according to the particular shape, Dewar bulb, Dewar tube, etc.
DIORAMA n.
A mode of scenic representation, invented by Daguerre and Bouton, in which a painting is seen from a distance through a large opening. By a combination of transparent and opaque painting, and of transmitted and reflected light, and by contrivances such as screens and shutters, much diversity of scenic effect is produce…