Abstract: The invention relates to a method and device for establishing and maintaining defined temperature and hygrometric conditions inside premises. The method comprises the following steps: a supply reservoir (1) is filled with water; water contained in the supply reservoir (1) passes into tubes (3) or hollow profiled elements (3) of an evaporator/exchanger (2); part of the water is exuded on the outer walls of the tubes (3) or hollow profiled elements (3); a thin film of water is created on the outer walls; said film of water is subsequently evaporated, whereby the water circulating in the tubes (3) is cooled; a flow of air to be cooled is generated with the aid of ventilation means (7); the refrigerated water in said air flow is atomized with the aid of atomizing means (6) in order to create a humidified and cooled air flow.

Abstract: A cassette is fitted with two cylindrical chambers, each of which has, in its center, a spool axis or shaft. The width of the cassette is slightly greater than the width of a strip of microfilm. The two chambers are joined by a pair of separate, flat plates, which extend the walls of the chambers so that the strip of film runs between the two plates, with a window in the central zone of the two plates. The width of the interval between the two plates is small, to press the film accurately into place at a focal plane of the optical system of a microfilm projector. The apparatus for the use of the cassette makes it possible to cause the film to circulate in both directions.