When we consider the numerous and rapid changes which take place in
our climate, it is a remarkable fact, that _the mean temperature of
a place remains nearly the same_. The winter may be unusually cold,
or the summer unusually hot, while the mean temperature has varied
even less than a degree. A very warm summer is therefore likely to
be accompanied with a cold winter; and in general, if we have any
long period of cold weather, we may expect a similar period at a
higher temperature. In general, however, in the same locality the
relative distribution over summer and winter undergoes comparatively
small variations; therefore every point of the globe has an average
climate, though it is occasionally disturbed by different atmospheric
changes.--_North-British Review_, No. 49.