Shabbat 8 - Throwing a basket
If one threw a round wicker basket from the street (public domain) into a private domain (courtyard), and the basket was ten hand-breadths high and over six hand-breadths in diameter, then he has thrown not an object but another domain, and for that he is not liable. That is because a basket which is that big qualifies as a private domain itself, and one is only liable for throwing objects, not domains. However, if it was smaller than six hand-breadths in diameter, then it is not a domain but an object, and for that he is liable.
That was the statement of Abaye. Rava added that if it was exactly ten hand-breadths high, then he is not liable either: some leaves are bound to protrude beyond the ten hand-breadths, and this is how high the public domain extends, so the object was never fully in the public domain, and for such partial transfers one is again not liable. And Abaye, what does he answer? He agrees in principle, but considers leaves insignificant.
If the basket overturned in the air and landed on its rim, then even if it was seven hand-breadths, one is not liable: while in the air, being three hand-breadths above the ground, it had its walls downwards, and using the principle that "one may extend the walls" we say that it already touched the ground while it was in the air above ten hand-breadths, and as we just saw, one is not liable for partial transfers.
Rav Ashi disagrees and makes him liable. He says that we can use the principle of "extend the walls" only when the extended walls make something fit for use, and in our case the walls of the basket extending downward do not help anybody.
Art: Peter de Wint - Still-life with a jug and wicker baskets