Eighteen Treatises from the Mishna, by D. A. Sola and M. J. Raphall, , at sacred-texts.com
§ 1. All the roofs of a town 1 [form] one reshuth, provided always there be not one roof, ten hands higher or ten hands lower [than the rest]. Such is the dictum of R. Meir; but the sages hold [that] every roof forms a separate reshuth. R. Simeon saith, "Roofs, as well as courts and wood-stores [inclosed places, form] one reshuth,
[for [the carrying and conveying of] all [such] utensils as were actually] therein [when] the Sabbath-rest [began], but not for those utensils [which were] in the house [when] the Sabbath-rest [began]."
§ 2. If a large roof he next adjoining a small one, [the owners of] the large [roof] are permitted [to carry utensils thither from the house], but [the owners of] the small [roof] are prohibited [so to do]. If a large court opens into a small one, through a gap [or breach in the wall], [the inmates of] the large [court] are permitted [by means of erub to carry or convey through the breach], but [the inmates of] the small [court] are prohibited [so to do], because it [the smaller court] is considered as a door [entry] to the large [court]. If a court [through the fall of its walls] is laid open towards the public reshuth, whosoever brings any thing from a private reshuth into the court, or
from the court into a private reshuth, is guilty. Such is the dictum of R. Eleazar. The sages hold, "that [whoever brings any thing] from the court into the public reshuth, or from the public reshuth, is absolved; since [by the fall of its walls, and the consequent opening] the court is become like carmelith."
§ 3. A court, [the corner walls of which have fallen down on the Sabbath, so] that [it] has been laid open towards the public reshuth on two sides; and also a house [which by the fall of the corner wall is thus] laid open on two sides; or an entry, the beam and posts of which have been removed, it is permitted [to the inmates to carry or convey thence] on that [particular] Sabbath; but it is prohibited [so to do] for the future, [on any subsequent day of rest]. Such is the dictum of R. Jehudah; but R José saith, "If it were permitted on that [particular] Sabbath, it would also be permitted for the future; but if it is prohibited for the future [on any subsequent day of rest], it is also prohibited on that [particular] Sabbath."
§ 4. If an attic be built over two [adjoining] houses—likewise bridges, the avenues to which are open at both ends—it is lawful [to carry or convey] underneath on the Sabbath. Such is the dictum of R. Jehudah; but the sages prohibit it. Moreover, R. Jehudah further said, "It is lawful to combine, by [means of] erub, an alley that is open at both ends," but the sages prohibit it.
91:1 In the East all roofs are flat.