The founders of geology at the beginning of the last century were suspicious oflaboratories. Hutton's well-known dictum illustrates the point: "There are also superficial reasoning men . . . they judge of the great oper- ations of the mineral kingdom from having kindled a fire, and looked into the bottom of a little crucible. " The idea was not unreasonable; the earth is so large and its changes are so slow and so complicated that labo- ratory tests and experiments were of little help. The earth had to be studied in its own terms and geology grew up as a separate science and not as a branch...