Tunneling

(p. pr. & vb. n.) of Tunnel

手打:南希

• Tunneling under rivers presents many more difficulties than driving through the hardest rock. Edward W. Byrn. 十九世纪发明进展.
• His experiments made him doubtful of the possibility of running such railroads, unless a great amount of very expensive tunneling and grading were first done. 鲁伯特·萨金特·荷兰. 历史性发明.
• It is believed that this was the first time that soft material met with in tunneling under a river has been solidified by means of fire. 佚名. 神奇的知识之书.
• An important engineering invention for tunneling through silt or soft soil is the so-called shield. Edward W. Byrn. 十九世纪发明进展.
• In tunneling under the river, nearly every conceivable combination of rocks and soils were met, but for the most part the material was silt. 佚名. 神奇的知识之书.

手打:南希