It is 35 feet 8 inches in diameter inside the bark four feet from the ground.
它在距离地面四英尺的树皮内直径为 35 英尺 8 英寸。
英语百科
List of gear nomenclature
(重定向自Inside diameter)
The addendum is the height by which a tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line; also, the radial distance between the pitch diameter and the outside diameter.