ABSTRACT
Climatic changes come on several different timescales. Between short-term fluctuations lasting a few years and changes extending over thousands of years there are variations over a few centuries which may have profound effects on natural phenomena and human affairs. It is variations on this scale, stretching over several generations, with which we are concerned in studying the Little Ice Age. It was a period which may be seen as beginning in the thirteenth and fourteenth centuries (Porter 1986) and then, after an interval of more clement conditions, culminating between the mid-sixteenth and the mid-nineteenth century. It was also a period of lower temperature over most if not all of the globe, sufficiently marked to have had important consequences, especially in certain sensitive areas in high latitudes and at high altitudes where conditions for plant growth and agriculture are marginal.
