Magnetic arc control enables the standard type of 250 watt or 400 watt vertical burning mercury vapour lamp to be used in a horizontal position, the lampholder being easily adjusted to accommodate either lamp.

Closely graded control of the light output in the vertical plane near the horizontal ensures that glare is kept to a minimum. At the same time sufficient light is emitted up to the horizontal to maintain continuity of visual accommodation. This principle of controlled cut-off, combined with a wide beam spread and high candle-power at the effective angles, gives maximum visibility.

Construction And Finish

The lantern is built almost entirely from silicon aluminium alloy. It consists of a main casting and a refractor bowl-retraining frame which is attached to the main casting by an adjustable hinge and is locked by a quick action spring catch. The joint between the frame and the castings is sealed by a rubber gasket, thus ensuring that the lantern remains weatherproof. The magnetic deflector gear is carried on bearers above the aluminium anodised reflector the contours of which are carefully preserved.

Spare Cover Bowl, Cat. No. SS701 can be obtained.