Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 411
loudy weather.Moreover, each unit maj^ contain ametal filament lamp, and will there-fore have the requisite brightness bynight. In Fig. 2 a second method of deal-ing with the problem is also shown.Tliere are marked out on the roofblack letters (MFJ), 2 metres long on ayellow ground. These letters… … Yia. 2.—liluiuiuated charadors for the guidanceof aviators at an Aerodrome in Germany. Experience has shown that the charac-ters sliould not be less tlian 20 cms.broad, and 1-5 metres high. Theycan then be perceived at a height of800 metres, and even when the aviatoris travelling at 80 kilometres…
Lighting
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
