It led to the production of the first chipped flint in the Eolithic Age; it invented the wheel and the sail, it discovered the Arts, in their crudest form, of smelting, forging, weaving and husbandry in the early dawn of our civilization; and it is today as eager as ever, if opportunity allows, to explore the unknown and investigate the untried for the very peculiar reward, the mental satisfaction it gives, which can never be measured by any pecuniary or social standard.    From Wordnik.com.  [The Research Council and Its Work] Reference

Eolithic (Pliocene)?.    From Wordnik.com.  [How to Observe in Archaeology] Reference