Yosef Karo

“ Paragraph 1 - If two houses are on two sides of the public domain and they are owned by one person or by two who connected their properties, if they are level, they are permitted to throw from one house to the other. If one house is higher than the other, it is forbidden for them to throw to each other unless they are throwing clay objects and other objects that will break upon falling. This all is referring to when a public domain goes between them, but if there is a karmelit between them, throwing between the houses is always permitted. ”

“ However, if a ledge extends to the karmelit, as long as it is ten high, it is permitted, whether it is wide or narrow, and whether the objects break or not, because there is no rabbinic enactment for the karmelit. ”