Production and application of light

Statistics on Incandescent Lamp Sales.¹ The sale of large tungsten filament lamps (as distinguished from the miniature types) totaled 344,000,000 during 1929, an increase of 8.7 per cent over the previous year´s sales. The fact that the production of large tungsten filament lamps alone is running well over a million lamps per working day will give some impression of the extent to which our modern life has become dependent upon this source of artificial illumination.