FIRE AS AN AGENT IN HUMAN CULTUEE 195 



each step in advance now requires a great outlay in patience and 

 money. 



The utilization of artificial light viewed so far as may be possible 

 in its entirety is a record of achievement in which the sensation of 

 wonder finds itself overworked. George lies, in his Flame, Elec- 

 tricity, and the Camera, makes illuminating excursions in this field 

 of marvels and touches the salient features. It is a trite saying, 

 however, that no one can keep abreast with the advances in a single 

 one of the specialties of science. 



Inquiries into the nature of light have furnished materials for a 

 classification of the kinds of light. It is now known that there are 

 a number of kinds and qualities of hght. The light with which the 

 common human activities are concerned is that form of "radiant 

 energy" to which the human eye in its development has adapted 

 itself, or, to turn it about, has caused the eye to be forced to its 

 appreciation. This is sunlight, the standard by which all the varieties 

 of hght observed by us are rated. The illumination engineer in the 

 endeavor to furnish light in the greatest amount and of most general 

 use seeks to approximate this white light. He strives to turn night 

 into day. 



The analysis of white light by the spectroscope immediately ren- 

 ders it evident that the eye is concerned with only the short range 

 of median colors to which it is adapted, the red, yellow, and orange. 

 The eye perceives all the spectrum the character of whose energies 

 is capable of inciting the function of vision. 



The human eye has developed in two lines, namely, 1, accomodation 

 to dayhght by structural developments to regulate the amount of light 

 falling on the sensitive surface, and 2, accommodation to diffused light 

 by which the sensitive surface registers to the minimum of radiation. 

 Man's eyes register to light only, and he is therefore required to move 

 about in the dark mainly by means of a tactical sense combining 

 other senses. That "seeing in the dark" is possible is a widespread 

 but false belief. 



The chronicle of fire, with its body of wonderful achievements in 

 the development of arts for the benefit of mankind, is nearing the 

 end. Other forces more wonderful are on the point of being unlocked, 

 and they will cause the crude thaumaturgy of fire to appear as ridic- 

 ulous as the incantation of a medicine man. 



FIREFLIES 



Of the natural sources of illumination the most suggestive and 

 perhaps forward-looking in the trend of modern science is the use of 

 fireflies for hght. As a method of illumination firefly light stands 

 alone. It can not be assigned as a step in the origin of the torch or 



