THE EARTH. 327 



not our present province to enter upon. It will 

 be sufficient, therefore, only to observe, that all 

 these appearances arise from the density of the 

 cloud, together with its uncommon and peculiar 

 situation with respect to the spectator and the 

 sun. It may be observed, that but one of these 

 three rainbows was real, the rest being only re- 

 flections thereof. It may also be observed, that 

 whenever the spectator stands between the sun 

 and a cloud of falling rain, a rainbow is seen, 

 which is nothing more than the reflection of the 

 different coloured rays of light from the bosom of 

 the cloud. If, for instance, we take a glass 

 globe, filled with water, and hang it up before 

 us, opposite the sun, in many situations it will 

 appear transparent ; but if it is raised higher, or 

 sideways, to an angle of forty-five degrees, it will 

 at first appear red ; altered a very little higher, 

 yellow ; then green, then blue, then violet 

 colour; in short, it will assume successively all 

 the colours of the rainbow ; but, if raised higher 

 still, it will become transparent again, A falling 

 shower may be considered as an infinite number 

 of these little transparent globes, assuming diffe- 

 rent colours, by being placed at their proper 

 heights. The rest of the shower will appear 

 transparent, and no part of it will seem coloured, 

 but such as are at angles of forty-five degrees 

 from the eye, forty-five degrees upwards, forty- 

 five degrees on each side, and forty-five degrees 

 downward, did not the plane of the earth prevent 

 us. We, therefore, see only an arch of the rain- 

 bow r the lower part being cut off from our sight 



