If a new window is made for light, its size [to spread tumah] is the large gimlet of the [Temple] chamber. If some of the window is left, [the size] is the height of two fingerbreadths by the width of a thumb. What are cases in which ‘‘some of the window is left’’? A window was being boarded up, but the job was not completed. The minimum size for a hole created by erosion through water, small animals, or salt is the size of a fist. If someone decided to use [this hole] for general usage, its size is a square handbreadth; if for light, the size of a gimlet. Lattices and screens combine to equal the size of a gimlet according to Beis Shammai. Beis Hillel say: Only when the size of a gimlet is in one place. [The above list establishes the criteria] to allow tumah to enter and to allow tumah to exit. R’ Shimon says: [These are the minimum dimensions] to allow tumah to enter, but to allow tumah to exit [the minimum amount is] a square handbreadth.