Shabbos Daf 8 שבת דַף 8

Abaye said: If one throws a reed basket (כוורת) into a reshus harabim and the basket is ten tefachim high but not six tefachim wide, he is liable because the basket is considered an object that was transferred.

But if the basket is six tefachim wide he is exempt because any object that is ten tefachim high and four tefachim wide is large enough to be considered a “reshus”, not an “object.” The reason is that the only throwing done in the Mishkan was specifically for small objects when the craftsmen threw small needles to one another. Therefore larger objects are considered a reshus, and one is not liable.

The reason why a round basket needs to be six tefachim wide is so that it can contain a rectangular object that is four tefachim wide.

Rava said that even if the object is less than six tefachim wide is exempt, because it is impossible that some slivers of the basket do not extend up above ten tefachim resulting in some of the basket in a makom petur. To be liable for transferring one must place the entire object within the domain.
(Abaye considers the slivers of basket that extend above ten tefachim insignificant).

Ulla said: If there is an post nine tefachim high in a reshus harabim and the public uses it to adjust their burdens on it, and one threw an object four amos away and it landed on the post, the person is liable since the top has the status of a reshus harabim.

He explains that if an object in reshus harabim is less than three tefachim high, people tread upon it and therefore is considered part of the reshus harabim.

If the object is between three and nine tefachim high the public neither treads upon it, nor uses it to adjust their burdens on it, it is either a karmelis if it is four tefachim wide or a makom petur if it less than four tefachim wide.

Rav Yehuda said: If one lifts one end of a bundle of reeds (זירזא דקני) from the ground and topples it forward, then lifts the second end from the ground and topples it forward, and does this numerous times until the bundle has been moved four amos in a reshus harabim, he is not liable until he lifts both ends of the bundle simultaneously and transports it four amos.

It is not considered an עקירה until both ends have been lifted from the ground simultaneously.