Abstract: An apparatus for the prevention of ice dams on roofs of edifices comprising a ventilator, a first and second outdoor temperature sensor. The first temperature sensor is located outside where snow will not collect. The second outdoor temperature sensor is located on the roof of the edifice where snow will collect. Both sensors are housed to protect the sensors from extreme weather conditions, such as sun and wind. The apparatus also comprises a thermostat for receiving the temperature readings from the first and second temperature sensors and manipulating the ventilator. The apparatus also provides a method of preventing ice dam formation on roofs of edifices, comprising the steps of detecting a first temperature reading of the ambient atmosphere, detecting a second temperature reading of the roof of the edifice, comparing the readings to determine whether conditions exist for ice dam formation, ventilating an air space below the roof of the edifice to cool the roof if ice dam conditions are present.

Abstract: A roll caster comprising a pair of rotatable rolls (1, 2), and mounting means (4, 5) for moving one of the rolls towards and away from the other, so as to adjust the gap between the rolls. A nozzle assembly (9) for directing molten metal into the gap between the rolls, is mounted with its outlet end projecting into the gap, with a suitable clearance. The nozzle assembly is mounted on a carrier (13) which is moved in accordance with the movement of the rolls, by means of a mounting comprising movable links (16, 17) so as to maintain the required clearance between the nozzle and the rolls.