A vow of silence has protected the mystery behind an ingenious invention for nearly 500 years. The secrets behind an amazing diving bell, a technical marvel which allowed men to stay underwater for hours at a time, might predate others by 200 years.
A vow of silence has protected the mystery behind an ingenious invention for nearly 500 years. The secrets behind an amazing diving bell, a technical marvel which allowed men to stay underwater for hours at a time, might predate others by 200 years.
