Holophane Three-Way Bowl Refractors are similar in size and mechanical construction to the standard symmetrical types, but the prism formation is designed to concentrate the light rays in three main directions instead of symmetrically around the unit.

This Three-Way concentration gives higher intensities than those obtained with the standard type and therefore permits of wider spacing with equivalent uniformity of illumination.

The Three-Way type distributes the light rays in three main beams and has been designed for installation of "T" street intersections.

List No.	Gas Filled Type Lamps (Watts).	Overall Dimensions ins.		Standard Position of Lamp* 80°
		Diam.	Height.
3/4437	60-100	6½	6	60mm.
3/4438	150-300	8½	7½	80mm.
3/4433	500-750	11¾	9	92mm.

^* From centre of filament to top of glass

Vertical Candle Power Distribution Curve.

Plan Candle Power Distribution Curve.
Through a 80° Cone.

Holophane 3-Way Refractors should be installed at a "T" street intersection where the widths of the streets does not exceed 80 feet. The maximum candle power is given from 70° to 80° from the vertical in three directions.

The two opposite beams are given with their maximum candle-power at 10° from the horizontal and the third beam at 90° from the horizontal. These units, therefore, should be installed at the side of the road and opposite the intersection.

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Holophane Ltd	Elverton Street, Vincent Square	London, S.W.1
Telegrams :- "HOLOPHANE, SOWEST, London"		Telephones :- "VICTORIA, 2491, 8258."

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