[Illustration: BUILDING THE GRADE. THE DREDGER CUTTING ITS OWN PATH AND DUMPING REMOVED SPOIL IN CENTRE TO FORM THE EMBANKMENT FOR THE TRACK] [Illustration: _Photos, Hill_] THE EMBANKMENT COMPLETED, WITH THE CANALS DUG BY THE DREDGERS ON EITHER SIDE] The only difficulty experienced in this manner of handling the marsh was that the marl torn out by the grabs and deposited upon the right-of-way was so saturated after its immersion for centuries that it dried very slowly, and delays were frequent and heavy in consequence. One layer of the dump had to be left exposed for a considerable time before the next could be added. But the method of building the embankment proved so eminently successful and efficient, that a new move was made to meet the necessity for allowing the excavated soil time to dry. Four additional dredgers were built, two for each canal, and these were set to work at intervals one behind the other. The foremost dredger laid the foundations of the embankment, the second raised it a further height some days later, and after another interval of time, the third dredger contributed its quota to the constructional work. In this way the task was expedited very materially. In some places the bog was found to be covered with mangrove trees, the roots of which spread like a thick net through the soil. The consequence was that the grabs tore up a large proportion of roots associated with the soil, and the former had to be used for embanking purposes, as it could not be separated from the inorganic matter. But this fibrous substance dried very quickly, and was so highly combustible that it had to be covered with a thick layer of broken stone to protect it from fire, and also to ensure solidity by packing tightly. [Illustration: HOW THE EMBANKMENT WAS BUILT ON THE KEYS The dredged material was pumped through the pipe line to fall between wooden fences to form the grade.] [Illustration: _Photos, Hill_] HOW THE REINFORCED CONCRETE ARCHES WERE BUILT WITHIN WOODEN MOULDS BUILDING THE “OVER-SEA” RAILWAY] The completed track has a somewhat novel appearance. There is the ridge of earth, flanked on either side by a broad ditch, cut by the dredgers and running as equidistantly from one another as if drawn with a parallel ruler. These side canals, however, serve to drain the permanent way to a certain extent. When the railway-builders made their way through this inhospitable region they did not meet a vestige of civilisation for over 30 miles. Then they came across pathetic evidences of attempts at reclamation here and there in the form of tumbling homes and isolated parties of half-starved negroes, vainly endeavouring to extract some sort of subsistence from the bog.