MIT Institute Archives & Special Collections Object of the Month:

Among the many perils of early aviation were various unknowns associated with innovations in design. Prudent engineers performed as many tests as possible on the ground, including the standard precaution of turning a sample plane upside down and filling its wings with sand until something broke. A widely-perceived need for more sophisticated testing inspired the evolution of wind tunnels. MIT's Technology Review noted that "a pilot who has taken an airplane off the ground and finds it to be unstable or unwilling to answer the controls is in a very unpleasant position..."