July, 1870: (a series of plans, detailing how the airship might be converted from air-ship to under-water ship are sketched, with numerous corrections and adjustments. Beneath, a series of calculations accounting for water pressure, balancing weights, air needed, power required to move the fins and propel the tail are repeatedly scratched out, accompanied by increasingly frustrated commentary.) Beneath, Verdie has written: Further below, scratched in apparent haste: