Chap. VI.
FRANCE.
231
worked by a capstan on land. There were also four pontoons with similar capstans, andnumerous boats, some with forty, others with eighteen oars to assist.
The pontoons were placed at regulardistances, and the cone was towed out byattaching the capstan ropes to the doublecable that surrounded it. A few minutesbefore 8 in the morning, the sea had risen9 feet up the cone, and a slight motionindicated that it was afloat: it stoodperfectly erect, balanced in every part,and needed no ballast or adjustment.
The water rose a few inches higher,when a gentle south wind moved it aboutits own diameter from the land, whichindicated that little labour would be re-quired to tow it forwards.
The great towing cable and the hawserswere fastened to the double cincture ofrope, a signal was given to slacken theropes which attached the cone to theland, and it was immediately moved for-wards by the rowers; standing out ofthe water 54 feet, it glided gently afterthe boats. About the middle of theday the vessels hoisted their sails, whenit proceeded so rapidly that boats loadedwith stones were fastened to it, whichsomewhat impeded its progress.
The vessels then reefed their sails, letgo their anchors, and were attached tothe girdle of the cone; the wind growingstronger, the second pontoon was gained,at forty minutes past 12; the third soonafter, and at a quarter past 3 it had ar-rived at its destined position.
The workmen were then ordered totheir posts. Cessart had arranged thatthe cables which held the casks should becut at points diametrically opposite toeach other, when he gave from the shorethe signal to do so, which he did at halfpast 3; the engineers then let fall fouranchors, and moored the cone to them.
The ropes which held twenty-two of thecasks being cut, it immediately sank18 feet; the cords had acquired addi-tional toughness from their strain andimmersion, and although the cuttingknives were loaded with forty pounds oflead, it required two strokes to separate them.
The two ropes which circumscribed the cone, and which were nearly 2 feet in circum-ference, were then taken off.
Twenty-one cones were put together, but eighteen only were made use of, the otherthree being sold during the revolution. According to Cessart, the first was placed in itssituation the 23d of June, 1786, and the last, the 19th of June, 1788.
These were not, however, placed at regular distances from each other. Cessart’s planwas departed from ; and the destruction of the timber work of the cones, a few years after-wards, was the consequence.
The second cone was placed 513 feet distant from the first, measuring from centre tocentre.
The third was at 159 feet; the fourth at 184 feet; the fifth at 381 feet; the sixth at416 feet; the seventh at 407 feet; the eighth at 448 feet; the ninth at 453 feet; the tenthat 492 feet; the eleventh at 737 feet; the twelfth at 817 feet; the thirteenth at 880 feet;the fourteenth at 905 feet; the fifteenth at 893 feet; the sixteenth at 1845 feet; the seven-teenth at 1630 feet; and the eighteenth at 1310.
The total length was 12,470 feet, measured from the centre of the two extremes; thedistance of the centre of the first cone to the fort on the Isle of Pelee, 3269 feet; and that
Q 4
Fig. 242.
PLAN OF MOORING.