《明史·志·卷六十三》
并且起龄木乐店到达飞云桥，占地以千里计算，需用役夫上百万，累积工夫十年，不能确保它的成功。
且起木栾店至飞云桥，地以千里计，用夫百万，积功十年，未能必其成也。
Besides, from Muleshop to Feiyun Bridge, it would take up hundreds of thousands of square miles, require millions of laborers, and take ten years to complete, without any guarantee of success.