harbour. Sea ice surrounding Iceland extended for miles in every direction and closed harbors to shipping. The population of Iceland fell by half, but that may have been caused by skeletal fluorosis after the eruption of Laki in 1783. Iceland also suffered failures of cereal crops and people moved away from a grain-based diet. The Norse colonies in Greenland had starved and vanished by the early 15th century because of crop failures and the inability for livestock to be maintained throughout increasingly harsh winters. Greenland was largely cut off by ice from 1410 to the 1720s. In his 1995 book, the early climatologist Hubert Lamb said that in many years, "snowfall was much heavier than recorded before or since, and the snow lay on the ground for many months longer than it does today." In Lisbon, Portugal, snowstorms were much more frequent than today, and one winter in the 17th century produced eight snowstorms. Many springs and summers were cold and wet but with great variability between years and groups of years. That was particularly evident during the "Grindelwald Fluctuation" (1560–1630); the rapid cooling phase was associated with more erratic weather, including increased storminess, unseasonal snowstorms, and droughts. Crop practices throughout Europe had to be altered to adapt to the shortened and less reliable growing season, and there were many years of scarcity and famine. One was the Great Famine of 1315–1317, but that may have been before the Little Ice Age. According to Elizabeth Ewan and Janay Nugent, "Famines in France 1693–94, Norway 1695–96 and Sweden 1696–97 claimed roughly 10 percent of the population of each country. In Estonia and Finland in 1696–97, losses have been estimated at a fifth and a third of the national populations, respectively." Viticulture disappeared from some northern regions, and storms caused serious flooding and loss of life. Some of them resulted in the permanent loss of large areas of land from the Danish, German, and Dutch coasts. The violinmaker Antonio Stradivari produced his instruments during the Little Ice Age. The colder climate may have caused the wood that was used in his violins to be denser than in warmer periods and to contribute to the tone of his instruments. According to the science historian James Burke, the period inspired such novelties in everyday life as the widespread use of buttons and button-holes, as well as knitting of custom-made undergarments for the better covering