ommentary,
was the joint work of Hoover and his wife--it was Mrs. Hoover, indeed,
who began it--and occupied most of their spare time, especially their
evenings--and sometimes nights!--and Sundays, through nearly five years.
They had been for some time collecting and delving in old books on China
and the Far East and ancient treatises on early mining and metallurgical
processes, and had accumulated an unusual collection of such books,
ransacking the old bookshops of the world in their quest. In 1902, Mrs.
Hoover while looking up some geology in the British Museum Library,
stumbled again on Agricola, which she had forgotten since the days she
was in Dr. Branner's laboratory. By invoking the services of one of
their friends among the old book dealers the Hoovers soon owned a copy.
Caught especially by the many curious and only half understandable
pictures in it they began to translate bits from it here and there,
especially the explanations of the pictures, and in a little while they
were lost. Nothing would satisfy them short of making a complete
translation. It became an obsession; it was at first their recreation;
then because it went very slowly it seemed likely to become their life
avocation.

They found an early German translation, which, however, helped them
little. The translator had apparently known little of mining and not too
much of Latin. They went to Saxony, to the home of Agricola, hoping to
get clues to the difficult things in the book by seeing the region and
mines which had been under his eyes while writing it, and finding
traditions of the mining methods of his time. But it was as if a sponge
had been passed over Agricola and his days. Fire had swept over the
towns he had known and all the ancient records were gone. The towns,
rebuilt, and the mines of which he had written were there, but of him
and of the ancient methods he wrote about there was hardly record or
even tradition. They went to Freiberg, where has long existed the
greatest German school of mines, the greatest mining school in the
world, indeed, until the American schools were developed--probably the
Germans would not admit even this qualification--and there they found no
more to help them than in Agricola's own towns. In fact, the Freiberg
professors seemed rather irritated by the advent of these searchers for
ancient mining history, for, as the savants explained, the Freiberg
methods and machines were all the most modern in the world; the