https://books.google.com/books?id=utroDAAAQBAJ&pg=PA16&lpg=PA16&dq=A rigidly spoked umbrella, opening suddenly in a small room, could seriously injure an adult or child, or shatter a frangible object. Thus, the superstition arose as a deterrent to opening umbrellas indoors&source=bl&ots=TDlkVFSDFy&sig=ACfU3U262vtcixNGMQy3LAev42G-PSt8SQ&hl=en&sa=X&ved=2ahUKEwiV5bnWpMfnAhUzknIEHRbDA30Q6AEwCXoECAoQAQ#v=onepage&q=A rigidly spoked umbrella, opening suddenly in a small room, could seriously injure an adult or child, or shatter a frangible object. Thus, the superstition arose as a deterrent to opening umbrellas indoors&f=false