PHYSICAL GEOGRAPHY 289 



Iceland the snow-covering persists so long during winter, that all 

 intercourse between the farmsteads takes place on snow-shoes, and 

 goods are transported on sledges, but in South Iceland sledges are 

 hardly ever seen and still less snow-shoes. Snow may fall in any 

 of the summer months, but in South Iceland it is only rarely that 

 there is snowfall of any consequence during summer. In the 

 northernmost districts it happens now and then, especially when 

 Polar ice is in the vicinity of the island, that it snows so heavily 

 for some days during mid-summer, that haymaking is suspended 

 and the cattle must be stabled for a shorter or longer time. On 

 the plateau snow-storms accompanied with frost occur now and 

 then in July and August, and upon the great ice-mountains (Jokulls) 

 it often snows in all months of the year. During a period of 30 

 years it snowed on an average 84 days annually at Stykkisholm, 

 44 days in the Vestmannaeyjar, 50 days at Berufjord, 45 days on 



Papev and 64 days on Grimsev. The amount of snow, as alreadv 



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mentioned, varies greatly according to the year. Snow-storms during 

 winter have often caused great disasters by destroying thousands 

 of sheep and many human lives. The annals of Iceland give us 

 much information of such disasters, and numerous written records 

 of many centuries show that the climate of Iceland has not changed 

 since its first colonization in the year 874. 



Hail is fairly common during winter, but rare during summer. 

 On Grimsey it hails about twenty-four times annually; in the Vest- 

 mannaeyjar twenty times, at Stykkisholm five times and on Papey 

 twice. The hail-stones are as a rule small, rarely larger than grit; 

 but during volcanic eruptions, they are much larger, and often 

 include grains of volcanic sand or ashes. Thunder is very rare and 

 occurs as a rule only in winter. The registered thunderstorms average 

 two in the -year in the Vestmannaeyjar, and only one at Stykkis- 

 holm and Berufjord, while none have ever been registered on Grimsey. 

 On the whole, thunderstorms are extremely rare in northern Ice- 

 land; thus at Audkula vicarage, in the district of Hunavatnssysla, 

 thunder was heard once only between 1857 and 1873. Thunder- 



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storms are more common along the southernmost part of the coast 

 (Eyjafjoll, Landeyjar, Rangarvellir) where they occur sometimes during 

 the summer also. The volcanic eruptions are almost always accom- 

 panied by thunder and strong electrical discharges. 



The climatic conditions we have hitherto been considering, have 

 naturally been those connected especially with the coasts and the 



