INVENTIONS AT PANAMA. 163 



York," the greatest dredge probably ever constructed ; built by the 

 American Contracting and Dredging Company, and by them used at 

 Panama. The engines of the largest Suez dredges had a force of 

 seventy-five horse-power. Those of the " City of New York " have a 

 force of three hundred. To run all parts of the complicated ma- 

 chinery, no fewer than eight are employed. The huge ladder which 

 carries the buckets is one hundred and ten feet long ; the chain to 

 which the buckets are immediately attached, if ruptured, would reach 

 from the top to the bottom of Bunker Hill Monument. Two dis- 

 charge-pipes, each three feet in diameter and one hundred and eighty 

 feet long, carry the earth to the banks. By means of steam-pumps, 

 as in the case of the Suez dredges, water is forced into the bell or 

 hopper, and the discharge facilitated. The effectiveness of this mechan- 

 ism is not due solely to its construction on an enlarged scale ; contriv- 

 ance comes in for part of the credit, and has effected part of the result. 

 One of the peculiarities of the American dredges may be referred to. 

 To steady the vessel and hold the buckets against the bank, two spuds 

 or pile-anchors are employed. In the case of the " City of New 

 York" these spuds are sixty feet high and two feet in diameter. 

 They pass through the hull, one on each side, and the iron chisel- 

 point at the termination of each weighs eighteen hundred pounds. 

 This is planted in the bottom. When spud No. 1 descends, it serves 

 as a pivot around which the dredge, carrying the bucket-ladder in 

 operation, slowly revolves, thus traversing the arc of a circle. When 

 No. 1 is raised. No. 2 is lowered, and serves in like manner as a center. 

 After this fashion, planting a foot at a time, this huge digging, 

 spouting creature, as one might term it, advances. The movement 

 through an arc is regulated by two distance-lines, so called. These are 

 attached to windlasses, one on each side of the forward deck, the 

 other end being attached to the shore. As one line is drawn in, the 

 other is paid out, and by this simultaneous process the motion in 

 curves is maintained.* A high degree of interest attaches to a struct- 

 ure combining power, ingenuity, and complexity as these are not 

 united in any other mechanism of the sort. Such among contrivances 

 of the kind is the " City of New York." 



With regard to the amount of excavation effected by the dredgers 

 of the American Company, Mr. Bigelow sets it down as about double 

 the largest output of any machine at Suez. Lieutenant Kimball, 

 comparing the output of the later American dredges with the best at 

 Suez, sets it down as more than double, twelve hundred cubic metres 

 per hour, as compared with four hundred and eighty. 



While in the matter of dredges Americans have contributed of late 

 more than others by fresh devices and an increase of dimensions, the 

 French seem to have effected like results with regard to excavators. 



* For these particulars as to the working of the spud?, etc., the writer is indebted to 

 Lieutenant W, W. Kimball, U. S. Navy. 



