for instance, the second Thames, the sections of arm to force downward. While using the ejector, and, in- mouth of the tunnel near the New Jersey bank of the which are made up of smaller pieces bolted together. deed, at all times, except when in hard silt or clay, the river, and by one long… … Fig. 3. THE DOWD TUNNELING SYSTEM. . grade to reach the surface not far from the river on the New 171% feet high by 16 feet wide. This form allows the short force than the backward pressure of the earth heading inci- York side. dent to the weight of the superincumbent column of water sections of…
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