The fact that the earth's climate changes in cycles from 
    warm to cold to warm, etc. ("Hockey Stick Hokum," 
    editorial page, July 14) was noted in the late 18th 
    century by Edward Gibbon in his "Decline and Fall of the 
    Roman Empire": "The reindeer, that useful animal, is of a 
    constitution that supports, and even requires, the most 
    intense cold. He is found on the rock of Spitzberg, within
    ten degrees of the Pole; he seems to delight in the snows 
    of Lapland and Siberia; but at present he cannot subsist, 
    much less multiply, in any country south of the Baltic." 
    In the time of Caesar, Mr. Gibbon wrote, the reindeer was 
    native to the forests of Germany and Poland, but in 
    Gibbon's time the animal was nowhere to be seen in those 
    parts. And between the Age of Caesar and the Age of 
    Gibbon, the Medieval Warming Period and the "Little Ice 
    Age" had taken place.