Apparatus for transferring visible images from a first surface to a second
surface and/or for fusing or fixing a visible image to a substrate,
comprising: a cylindrical member secured between two round end plates to
form a cylindrical structure; a volatile liquid incorporated within the
cylindrical structure in a cavity, at least one wall of which is
thermally connected to the cylindrical member; and a heater that heats
the liquid to an operating temperature, wherein the amount of the
volatile liquid is such that all of the volatile liquid would be
evaporated at a temperature that is less than about 20.degree. C. above
the operating temperature.