699 



and according to observations during 25 years the lowest tempe- 

 rature is — llj6^, tlie liigliest 21,2^, but tliese extremes are very 

 rare and on tlie wliole of very sliort duration when they occur. 

 Tlius it is evident, tliat tlie temperature of tlie Fseroes is rela- 

 tively high in winter, low in summer, and very uniform all the 

 year round. It is of course the direct influence of the sun that is 

 of special importance to the algae, and on hot, sunshiny days the 

 amount of heat and consequently the evaporation and drying in- 

 crease considerably. But days of really hot sunshine are as a rule 

 few, (the Faeroes have no so-called summer days, according to 

 Willaume-Jantzen); moreover, the sun's warmth acts directly, 

 as a rule, for but a short period and is soon replaced by rain, fogs 

 or clouds, so that the danger of the algse on the Fseroese coasts 

 being exposed to high temperature and consequenth^ to evaporation 

 is greatly diminished. 



The amount of humidity in the air is rather high in the 

 Faeroes; for the whole year it is 82, in summer a little more, 

 about 85, in spring a little less, about 80. Deviations naturally 

 may occur, but are generally of short duration. 



The very uniform and low mean temperature of the air to- 

 gether with the high degree of humidity, both varying but a little 

 from the normal, are certainly of great importance to the littoral 

 algal vegetation, the very luxuriant growth of which is certainly due 

 for the most part to these conditions. This view has partly also 

 been put forward by Simmons (75). On page 263, he writes: »Das 

 Auftreten vieler Arten in w^eit hoherem Niveau als sonst, kaiin 

 deshalb, was die faroische (und wohl auch Nordlands) Algenvege- 

 tation betrifft, nur oder wenigstens am besten durcli die Temperatur- 

 verhaltnisse erklart werden.« In addition to the temperature, the 

 little direct sunshine, the weaker light on the whole, the humid 

 air with much rain and fog, and especially the rough sea are 

 naturally likewise important factors. 



e. Light. 



The climate of the Faeroes is, as already mentioned, rich 

 in fogs, rain, and cloudy weather, and on the other hand rather 

 wanting in sunshine. According to Willaume-Jantzen, the 

 amount of clouds at Thorshavn is 7,4 (0 = clear sky; 10 = over- 

 cast); and the Faeroes have in all 178 »cloudy days«, that is, 



Botany of the Fseroes. 45 



