Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 71
,it was exceedingly difficult, if notimpossible, to obtain reliable data as to crater diameters. For these reasonsit appeared to him that the Society mightadd to the good works which it had alreadyaccomplished by undertaking, by meansof a suitable small committee, thecodification of such points.… … Fig. 4.—Patent electric signalling projectors with sphero-paraboloid reflectors,dioptric lens and Morse key. {Mr. A. Lyon.) might also be done to encourage greateruniformity in the matter of candle-powerratings, emission and illumination curves,and data of that character. Turning specifically to…
Lighting
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
