GEMARA: Shall we assume, that our Mishna is not according to Hananiah, as we have learned in a Boraitha, viz.: "Boards may be put up at a well and ropes for a fence of a caravan, but Hananiah said, that ropes for a well are permitted but not boards"? Nay; we may say, that our Mishna agrees with Hananiah; but a well containing rain-water is one thing and one containing spring-water is another. Our Mishna treats of spring-water and Hananiah refers to rain-water. To make an enclosure around a well of rain-water is permitted only during the time of the pilgrimage to Jerusalem.