Show cloore get 1 professor tyndall used to explain to popular audiences with alio aid of a brilliant experiment that the blue color of the sky Is owing to floating par tides of invisible dust that break up and scatter the short waves which are the blue waves 0 light this as a writer in knowledge shows occure principally at a creat elevation where the atmospheric dust 1 extremely fine while in the lower regions of the air where the dust 1 coarser the scatter luff affect all the rays or colors alike the fringes of clouds seen nearly in the direction of the pun are largely due to dust which especially accumulates in tho neighborhood 0 clouds and retracts refracts the around their edges |