The defendants, whose liability we have to determine, knew the boy possessed the shanghai, but, according to the findings of fact, as I understand them, they made no attempt to deprive him of it, though one or other of them did warn him of the dangers of its use and did forbid him to use it elsewhere than at his own home. Mayo J., who tried the action, considered that these admonishments were not enough and that, having regard to the risk of injury to person or property, accidental or intentional, involved in a boy of that age bearing a shanghai, the parents were guilty of negligence.
On appeal to the Full Court, his decision was reversed by Napier C.J., Angas Parsons and Reed JJ. on the ground that it exacted too high a degree of care, one out of step with the general practice and understanding of ordinary people, and that the parents had done all that a reasonable person could demand of them, the only further step open being to attempt to prevent the boy retaining or obtaining possession of a shanghai. As SO often happens in the law of tort, the liability of the party is seen to depend on a vague and uncertain standard giving little guidance either to judge or litigants.
A nice assessment of the risk to persons or property from a boy in possession of a shanghai gives but small assistance in forming a conclusion upon the measures a parent is called upon to take. Everyone knows that a stone discharged from a properly made shanghai will break an electric globe, a roofing slate, or window, and may do more than trivial injury to head, face, or finger, and that the chances of a boy making any of these his target may be arranged in a sharply descending scale. That shanghais are not instruments of precision is common knowledge and it is apparent that in thickly populated and built-up areas the risks attending their use are greatly increased and at the same time the boy finds fewer legitimate occasions for discharging a shanghai than he would in more open country. If the important consideration be, as no doubt it is, how the community regards these risks, whether as nothing but unavoidable or reasonable incidents of vigorous boyhood, or as something reprehensible that a parent or guardian may and ought to stop, then we are thrown back to a great extent on our concep- tions of what is reasonable and proper, practical and usual.
It is true that civic authority and school masters have always frowned upon the instrument and have attempted actively to repress it. This, I think, has been the case not only here but in England, where substantially the same instrument is known by the ancient name of catapult, and in America, where it is called a sling- shot. Civic authority has perhaps carried on an ancient tradition from the days of the stone bow which must have served the same