500 DEVELOPMENT OF ILLUMINATION. 



only as a luxury for illumination. Hence, up to a few years ago, all 

 avocations ceased at dark. Four years ago the writer, while encamp- 

 ing at Walpi, noticed only a solitary light at night in the pueblo. 

 There was at that time a demand for candles. Two years later a num- 

 ber of lights shone from the windows of the village. Lately coal oil 

 has become known; a great many families possess the luxury of a coal- 

 oil lamp, and this has worked a great change in the habits of the peo- 

 ple. This seems in epitome the history of illumination. 



