42 Introduction 



From the above tables it will be seen that 

 the lowest temperature of any month in 

 Shetland is January. The month possessing 

 the highest temperature is July. Thus, in 

 Shetland, the annual mean temperature is 

 2-63 above Orkney, and 1*08 below Glasgow. 



The prevalence of moisture is a character- 

 istic feature of all insular climates, and none 

 the less in Shetland. It is to be regretted, 

 however, that it has not been possible to 

 obtain data as to the rainfall in the islands. 

 If such record has been kept by any reliable 

 person, he has not, as far as can be discovered, 

 given his facts to the world. 



The same difficulties which prevented 

 Edmondston from providing similar informa- 

 tion in 1845 has met the present writer in 

 1902, namely, that such observations as are 

 known to have been taken by residents have 

 been irregular. In a question of science one 

 cannot give the result of occasional observa- 

 tions in any manner likely to be inferred as 

 an assumption of authority. 



Calculated very roughly, however, the 

 writer estimated the rainfall in Unst at about 

 25 inches, estimating from January ist, 1903, 

 to middle of June in the same year. 



