《徐霞客游记·滇游日记二十九》
从它上方往西行二里，越过下厂，抵达上厂，可坑谷又在中间隔开了它们，分为两条岔路而来，一条来自东北，一条来自西北，而炉子房屋盘踞在两条路之间。
从其上西行二里，越下厂，抵上厂，而坑又中间之，分两岐来，一自东北，一自西北，而炉舍踞其中。
From the top of the cliff, go west for two miles, cross the lower factory, and arrive at the upper factory. The pit valley separates them in the middle, and they are divided into two forks, one from the northeast, the other from the northwest, and the furnace house is located between the two roads.