130 The Colour of the Sea 



Valparaiso to San Francisco. Excepting the equatorial part, 

 stretching from Cape Blanco to Panama and round the coast 

 of Central America to near Mazatlan, the west coast of the 

 American continent between the fortieth parallels is the weather 

 shore of the Pacific Ocean. All along it cold and green water 

 is met with, in the same way as we have seen to be the case 

 on the Atlantic coast of Morocco. On the South American 

 coast the green water was found to extend, with few interrup- 

 tions, from Valparaiso, lat. 33 S., to Cape Blanco, lat. 4 27' S. 

 As on the Morocco coast, the green colour and the low tempera- 

 ture of the water are found only close to the shore. At a 

 distance of ten miles outside the colour is blue, and the tempera- 

 ture normal for the latitude. There can be little doubt that, 

 as the localities where the green water occurs are geographically 

 homologous, so the substance which produces the colour is 

 generically the same, namely, chlorophyll. 



The following particulars are taken from my unpublished 

 journal. The only ports or anchorages where the water was 

 blue were Huasco, lat. 28 27' S., temperature of the surface 

 water 147 C., and Carizal, lat. 28 5' S., temperature 15-1 C. 

 The occurrence in this latitude of blue water with so low a 

 temperature is very remarkable. 



At Antafogasta, lat. 23 39' S., the water was greenish- 

 blue, and its temperature was 18-0 C. Between this port 

 and Iquique the ship's course took her to a distance of nearly 

 twenty miles from the coast, and there the colour of the water 

 was ultramarine and its temperature 21-2 C. At Iquique 

 the water was quite green, and its temperature 17 C. Between 

 this port and Arica the water was quite green, even at a distance 

 of five miles from the coast, where the temperature was 19-5 C., 

 but on anchoring at Pisagua, lat. 19 36" S., the temperature 

 of the water was only 15-2 C. At Arica, lat. 18 28' S., the 

 water was equally green, but its temperature was 19-5 C. 

 Arica lies in the angle where the trend of the coast changes 

 from north to about north-west. From Arica the ship made 

 a longer run to Chala, lat. 15 49' S., keeping at a distance 

 of fifteen to twenty miles from the coast. Here ultramarine 

 water was met with, its temperature rising to 23-2 C., but 



