Of all the definitions of accident, as the term is used in equity, the best and most accurate, is undoubtedly that of Pomeroy,1 which is as follows: "Accident is an unforeseen and unexpected event, occurring external to the party affected by it, and of which his own agency is not the proximate cause, whereby contrary to his own intention and wish, he loses some legal right or becomes subject to some legal liability, and another person acquires a corresponding legal right, which it would be a violation of good conscience for the latter person, in the circumstances, to retain."