It was called the "mother lode", a deposit of silver so massive that it
would produce $300-million in its first 25 years of operation, establish
Nevada as a state, and bankroll the Union Army in the Civil War. Named
after an early investor, we'll see how the Comstock Lode, discovered
near Virginia City, proved to be a scientific laboratory from which vast
improvements in mining technology and safety were pioneered, including
innovations in drilling, ventilation, drainage, and ore processing.