DREDGING FOR INDUSTRIAL PURPOSES 



241 



exclusive purpose of reclaiming low and marshy lands in localities 

 near large cities. In these cases hydraulic dredges are employed 

 to excavate the materials from the bottom, raise them to the 

 surface and convey them to the lands to be filled by means of long 

 lines of pipes. Thus in the year 1885 the dredge "Badger" was. 

 used at Coney Island, N. Y., to fill up some lowlands which were 

 sold at a high price for amusement and residence purposes. 



In the Engineering News, June 13, 1901, was given a description 

 of filling up tide-water flats at Seattle, Wash., which is given here 

 in a condensed form. 



The city of Seattle, Wash., is built upon the hills lying 

 between Puget Sound and Lake Washington, there being very little 



FIG. 80. Tide Lands at Seattle. 



flat ground for manufacturing purposes. Between the city proper 

 and the suburb of West Seattle is a large area, a portion of Elliott 

 Bay which is overflowed at high tide, but which is entirely bare 

 at extreme low tide; the variation from mean low water to 

 extreme high tide, being 16.7 ft. These tide flats have been filled 

 with material taken from two waterways as indicated in Fig. 80, 

 each one 1000 ft. wide and 30 ft. deep at low water. These water- 

 ways connect toward the South with Duwamish River and with 

 a third waterway running east from the southern end of the east 

 waterway to the foot of the hill, where it connects with the pro- 

 jected ship canal which is to be 140 ft. wide and 30 ft. deep to Lake 

 Washington. The difference in level between low water at the 



