174 Star anfr TOeatber (Bossip 



Protection Wall, popularly known in the district as 

 the Promenade. The sea was dashing against the Wall 

 with winter-like fury, and as the spray shot up in the 

 sunlight rainbows appeared on it apparently at a 

 distance from where I stood of some fifty or sixty 

 feet. It was a scene of unforgettable beauty, heightened 

 by the presence of a brig under close -reefed topsails 

 labouring in the heavy seas scarce a quarter of a mile 

 from the rocky shore. 



How far off is the rainbow in reality ? When the 

 Beagle was anchored in an inlet in the southern part 

 of the Chonos Archipelago, a storm " worthy of Tierra 

 del Fuego," says Darwin, raged with great fury. 

 " During a few minutes there was a bright rainbow, 

 and it was curious to observe the effect of the spray, 

 which, being carried along the surface of the water, 

 changed the ordinary semicircle into a circle a band 

 of prismatic colours being continued, from both feet 

 of the common arch across the bay, close to the vessel's 

 side, thus forming a distorted, but very nearly entire 

 ring." 



A rainbow, my valued friend and correspondent, 

 Mr. C. T. Whitmell, tells me, is indefinitely far away, 

 because it is produced by parallel rays of light. " It 

 is not located in the drops," he says, " though due to 

 them. Whether the drops are a yard or a mile away 

 makes no difference to the distance of the bow. The 

 image of the sun reflected from a mirror a yard away 

 is not close to you. It is only the glass that is close. 

 As you walk to or from a bow the distance of the bow 

 itself is unaltered, and its size (angular magnitude of 

 radius 41 degrees) remains unchanged a proof that 

 it is indefinitely distant." 



