VOYAGE TO ALGERIA. 195 



violent. There had been scarcely a gleam of sunshine 

 throughout the day, but the cloud-forms were fine, and 

 their apparent solidity impressive. On Thursday morn 

 ing the green of the sea was displaced by a deep indigo 

 blue. The whole of Thursday we steamed across the 

 bay. We had little blue sky, but the clouds were again 

 grand and varied cirrus, stratus, cumulus, and nimbus, 

 we had them all. Dusky hair-like trails were some- 

 times dropped from the distant clouds to the sea. 

 These were falling showers, and they sometimes occu- 

 pied the whole horizon, while we steamed across the 

 rainless circle which was thus surrounded. Sometimes 

 we plunged into the rain, and once or twice, by slightly 

 changing our course, avoided a heavy shower. From 

 time to time perfect rainbows spanned the heavens from 

 side to side. At times a bow would appear in frag- 

 ments, showing the keystone of the arch midway in 

 air, and its two buttresses on the horizon. In all cases 

 the light of the bow could be quenched by a Nicol'" 

 prism, with its long diagonal tangent to the arc. 

 Sometimes gleaming patches of the firmament were 

 seen amid the clouds. When viewed in the proper 

 direction, the gleam could be quenched by a Nicol's 

 prism, a dark aperture being thus opened into stellar 

 space. 



At sunset on Thursday the denser clouds were 

 fiercely fringed, while through the lighter ones seemed 

 to issue the glow of a conflagration. On Friday morn- 

 ing we sighted Cape Finisterre -the extreme end of 

 the arc which sweeps from Ushant round the Bay of 

 Biscay. Calm spaces of blue, in which floated quietly 

 scraps of cumuli, were behind us, but in front of us was 

 a horizon of portentous darkness. It continued thus 

 threatening throughout the day. Towards evening the 

 wind strengthened to a gale, and at dinner it was diffi- 



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