HOLOPHANE LTD., LONDON, S.W.1.

A new development in street lighting technique employing horizontal burning Mercury Discharge Lamps, and also providing semi-cut-off light distribution characteristics.

The high intrinsic brightness of the light source is shielded by the reflector assembly in the lantern hood, while the combined reflector refractor assembly affords a controlled two-way non-axial distribution, promoting adequate road surface and background brightness in accordance with Group "A" requirements.

These lanterns employ two-piece refractors so designed that the prismatic surfaces are internally sealed, presenting smooth exterior surfaces. Available in types suitable for Groups "A" and "B" roads, and all installation requirements.

Designed to provide suitable vertical and lateral light control in conjunction with Sodium Discharge Lamps. Two-piece refractor panels with internally sealed prisms and smooth exterior surfaces, re-direct the light flux into a well-controlled two-way non-axial distribution.

Simplicity and efficency, together with low costs, are the primary features of this series. Suited to both Groups "A" and "B" installations, together with alternative refractor desgins for symmetrical and two-way non-axial distributions.

This lantern is designed for use with vertical burning Mercury Discharge Lamps. The light control is obtained by the use of reflector diffuser prisms carried on the inside of the glass, designed to give wide spread of light at realatively low angles and a more restricted spread at high angles of emission.

Two sizes are available, to suit Group "A" and "B" installations; the refractor bowl can be supplied for symmeterical, two-way axial, or two-way non-axial distribution; this lantern is also available for side-entry mounting.