Page:Popular Science Monthly Volume 90.djvu/34

 Efficiency Methods in Hauling and

���One of the most important duties devolving upon the engineer corps of the United States Army is the dredging of channels and harbors, be- cause the ocean bottom is con- stantly shifting and debris of all kinds is settling in navig- able inlets. In the Mobile, Ala., district, there are three outer bar channels where sea- going dredges work, and eight inner channels where pipe-line dredges are used, one of which is the Wahalak, illustrated in the oval above and in the con- tinuous picture on the right

��18

�� �