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SCIENCE PROGRESS. 



very much higher regions of the spectrum of transverse 

 ethereal vibrations, then it must become a question of degree 

 and of wave length, as implied above by the writer, and no 

 perfectly simple statement can be made. 



The activity of ordinary sunlight in promoting the 

 discharge of electricity into the atmosphere is evidently a 

 question of great meteorological importance ; but it is enor- 

 mously affected by the condition of the earth's atmosphere, 

 At high elevations the rays are very active, but in valleys 

 the power is less, and on many days in a town there is 

 hardly any power left at all. The writer's assistant, Mr. 

 Davies, constructed a portable apparatus with which he 

 made many observations in Wales and other places during 

 last summer at different heights and at different periods of the 

 day. The results are such as might naturally have been 

 expected, but we do not yet know whether the sun 

 emits any X rays at all detectable in the higher region of the 

 atmosphere, or whether this latter variety of radiation is 

 an artificial product recently introduced by man into the 

 operations of Nature. 



Oliver Lodge. 



