便是

suǒ wèi sòng dào ài ěr lán biàn shì yuè guò láo fáng de fáng dǐng cóng yī gè yuàn zi pāo dào lìng yī gè yuàn zi

所谓送到爱尔兰，便是越过牢房的房顶，从一个院子抛到另一个院子。

To be sent to Ireland was to be thrown from yard to yard over the roof of the cell.