190 BULLETIN 139^ UNITED STATES NATIONAL MUSEUM 



of the speaker would be of advantage. Consequently artificial light 

 may be essential to communications at night. It is of frequent ob- 

 servation that light is used and required by aborigines in circum- 

 stances where legends and stories are told after nightfall. The value 

 of noting the facial expression of the speaker is also important. Fol- 

 lowing this by-product of the subject it may be inquired whether 

 there is a basis for the observation that the speech of various groups 

 of men is fully gesture-aided, incompletely aided, or destitute of such 

 aid. Gestures may be considered as the communication of ideas by 

 means of muscle reading or as symbolic or pictorial, suggesting the 

 incorporation or survival of sign language as an element of spoken 

 language. 



The impression is that artificial light is an important factor in aid- 

 ing the expression of ideas through speech. 



It is interesting to note that architecture and light are so closely 

 connected in cause and effect. The house is usually thought of as a 

 protection against cold, heat, rain, or wind, but rarely as a protection 

 against light. Nevertheless this feature is as prominent as any men- 

 tioned, due weight being given to the environment. The racial char- 

 acters of house construction are not considered here, but it will be 

 found that the simple dwellings of uncivilized races have covered the 

 light problem as well as the complicated houses of the civilized. It 

 may be remarked that the window opening and roofs of the houses 

 of civilized man are the chief features by which artistic expression of 

 buildings is achieved. 



Many domestic industries were carried on by firelight, and the 

 family gathered about the hearth has always formed a picture which 

 can not be excelled in primitiveness. Needs, however, for a rather 

 special concentration and position of the source of illumination stimu- 

 lated the invention of holders, brackets, stands, etc., about the fire- 

 place, using primitive wood illuminants whose combustion produced a 

 reek of smoke, requiring a long experience to produce a partial im- 

 munity. For moving the fight about more freely then came the 

 torch stand, the candleholder, or some form of grease lamp. Gradu- 

 ally occupations which required careful seeing developed forms of 

 lighting apparatus suited to their special needs, as the weaver's lamp 

 which could be hung over the work, the brewer's lamp, which could 

 be stuck in a post or barrel, and the fike. Often the kitchen pre- 

 served the most primitive styles of illumination, while the "best 

 room" had the latest. There arose, therefore, in the early 

 period a considerable diversity in illuminating apparatus designed for 

 special needs without in any way leading to the production of better 

 light. The effect, however, of the increased utifization of light 

 through increasing the hours of labor is notable and has produced a 

 great effect upon human progress. 



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