The church of the house, constructed in such a manner as to separate the Great Convent from the Boarding-school like a veritable intrenchment, was, of course, common to the Boarding-school, the Great Convent, and the Little Convent. The public was even admitted by a sort of lazaretto entrance on the street. But all was so arranged, that none of the inhabitants of the cloister could see a face from the outside world. Suppose a church whose choir is grasped in a gigantic hand, and folded in such a manner as to form, not, as in ordinary churches, a prolongation behind the altar, but a sort of hall, or obscure cellar, to the right of the officiating priest; suppose this hall to be shut off by a curtain seven feet in height, of which we have already spoken; in the shadow of that curtain, pile up on wooden stalls the nuns in the choir on the left, the schoolgirls on the right, the lay-sisters and the novices at the bottom, and you will have some idea of the nuns of the Petit-Picpus assisting at divine service. That cavern, which was called the choir, communicated with the cloister by a lobby. The church was lighted from the garden. When the nuns were present at services where their rule enjoined silence, the public was warned of their presence only by the folding seats of the stalls noisily rising and falling.