The fluorescent bulb of the lamp reduces inherent brightness of the light source and so reduces the likelihood of glare from the lantern. The prism design co-operates with the fluorescent mercury lamp to produce a main beam at 78° from the downward vertical which is designed to provide good road surface brightness in relation to modern practice in mounting heights and spacing.

Specification

Special Features. One-piece cast light alloy body combines end support and opticell into one unit, with smooth outer glass refractor bowl hinged to give easy access to interior on releasing two captive screws. Asbestos gasket between boy and refractor bowl ensures full weather protection. The smooth outer surface of refractor bowl resists grime and dirt accumulation, thus requiring less cleaning attention. The bowl is of heat resisting glass.

Optical System. The internally moulded prisms of the refractor bowl are designed to give a concentrated beam of high intensity at peak level. Re-directing as much light as possible to the road surface, the optical system ensures that the maximum light from the merucry lamp is distributed to the lower hemisphere.

Materials. The lantern body is made from a silicon aluminium casting, specially selected for its resistance to corrosion. The gasket is made from asbestos. Other components are non-ferrous metals.

Finish. The internal surface of the body is finished in stove enamel white and the outer in aluminium.

Installation. The end support has an entry for a 5 3/8" length of 1¼" B.S.P. plain barrel. This is gripped by three 3/8" B.S.W. set screws to the column bracket. Wiring is brought to a heavy duty porcelain terminal block.

A cable clamp is provided for the incoming leads.

Lamps. ATLAS 250 watt or 400 watt colour corrected mercury type MBF/U lamp.

Catalogue Number.

PJC/G.1400 250W or 400W MBF/U lamp.