A question of historical interest is how to estimate the age of
historical objects based on some ag-related characteristics of the
objects.  For example, the variables in this dataset can be used
to estimate the age of Egyptian skulls.  The response variable is
Year the other four variables are possible predictors.

Variable     Definition

Year         Approximate year of skull formation (negative = B.C.,
             positive = A.D.)
MB           maximum breadth of skull
BH           Basibregmatic height of skull
BL           Basialveolar length of skull
NH           Nasal height of skull