《墨子·61章 备突》
译文城墙内每百步设置一个 突门 ，各个 突门 内都砌有一个瓦窑形的灶。灶砌在门内四五尺处。
城百步一突门，突门各为窑灶，窦入门四五尺，为其门上瓦屋，毋令水潦能入门中。
Translation: Set up a "tu men" every hundred steps along the city wall, and build a kiln-shaped stove inside each "tu men". The stove should be built four or five feet inside the gate.