1) CARRYING FROM ONE RESHUS HA'YACHID TO ANOTHER THROUGH RESHUS HA'RABIM
QUESTION: The Gemara explains that one may not lift a bucket from a well (a Reshus ha'Yachid) into the window of one's home (also a Reshus ha'Yachid) through Reshus ha'Rabim, unless there is a ten-Tefach-high wall of earth around the well. The wall of earth necessitates that one lift the bucket more than ten Tefachim high in order to pull it into the window. Consequently, the bucket does not pass through Reshus ha'Rabim at all, since the airspace ten Tefachim above the ground of Reshus ha'Rabim is considered a Makom Petur and not Reshus ha'Rabim.
The Gemara clearly assumes that one is not permitted to carry from one Reshus ha'Yachid to another through Reshus ha'Rabim. This assumption, however, is not so simple. The Mishnah in Shabbos (96a) teaches that it is prohibited to transfer an object along the length of Reshus ha'Rabim, but not from a Reshus ha'Yachid on one side of Reshus ha'Rabim to a Reshus ha'Yachid on the other side.
Perhaps the reason one is prohibited to carry a bucket from a well to one's home (when there is no wall around the well) is unrelated to the fact that the first domain is a Reshus ha'Yachid. Rather, it is prohibited mid'Rabanan to carry from Reshus ha'Rabim to Reshus ha'Yachid, even if the object never came to rest in the Reshus ha'Rabim.
This suggestion, however, is also difficult. The Mishnah earlier (97b) states that when one sits on a roof to read a scroll, and one end of the scroll rolls down but does not reach the ground (or ten Tefachim from the ground) of Reshus ha'Rabim, he is permitted to bring the scroll back. Similarly, when one sits on a Karmelis to read a scroll, and one end of the scroll rolls into Reshus ha'Rabim, he may bring the scroll back. In both cases he is allowed to bring the scroll back because two conditions are met. First, one side of the scroll remains in his hand. Second, the other side of the scroll did not land in an area from which it would be forbidden mid'Oraisa to carry the scroll back to its place (see Eruvin 103a). Similarly, in the case of the Gemara here, one should be permitted to carry the bucket through Reshus ha'Rabim into Reshus ha'Yachid, because these two conditions are met. First, the bucket remains in his hands. Second, it was never in a place from which it would be forbidden mid'Oraisa to carry, since it was only in the airspace of Reshus ha'Rabim and not on the ground.
(a) The RASHBA explains that the Gemara here follows the opinion of Rebbi Akiva, who maintains that "Kelutah k'Mi she'Hunchah Dami" -- passing an object through the airspace of Reshus ha'Rabim is equivalent to laying the object on the ground of Reshus ha'Rabim (see Rashi to 98b, DH Toch). Therefore, the second condition is not met -- even when the bucket merely passes through the airspace of Reshus ha'Rabim, it is indeed in a place from which one may not carry mid'Oraisa.
(b) The RITVA answers that in the Gemara's case of a bucket full of water lifted out of a well and over into a window through Reshus ha'Rabim, the law is more stringent than usual. Due to the weight and bulkiness of the bucket, the bearer might momentarily let the bucket rest on the ground while it passes through Reshus ha'Rabim. Therefore, he must lift it ten Tefachim or more from the ground, so that there is no concern that it will rest in Reshus ha'Rabim.
(c) The BACH (OC 354) answers that one is permitted to return a scroll to its original place only b'Di'eved, when it accidentally fell into another Reshus. One is not permitted to unroll the scroll intentionally into the other Reshus and then to roll it back. Accordingly, one should not be permitted to reach out into the well l'Chatchilah in order to carry the water to his home.
(The Rishonim may have considered the case of the well to also be a case of b'Di'eved, since the water was drawn from the well in an entirely permissible manner. Once the bucket is full, to return it through Reshus ha'Rabim to his home is considered carrying through Reshus ha'Rabim b'Di'eved and not l'Chatchilah. -M. KORNFELD)