Slightly different version:
“...One end of the chain was then bolted to that which hung down the face of the Caernarvon pier; whilst the other was attached to ropes connected with strong capstans fixed upon the Anglesea side, the ropes passing by means of blocks over the top of the pyramid of the Anglesea pier. The capstans for hauling in the ropes bearing the main chain were two in number, manned by about 150 labourers. When all was ready, the signal was given to 'Go along!' A band of fifers struck up a lively tune; the capstans were instantly in motion, and the men stepped round in a steady trot. All went well. The ropes gradually coiled in. As the strain increased, the pace slackened a little, but 'Heave away! Now she comes!' was sung out. Round went the men, and steadily and safely rose the ponderous chain. The tide had by this time turned, and bearing upon the side of the raft, now getting freer of its load, the current floated it away from under the middle of the chain, still resting on it, and it swung easily off into the water. Until this moment a breathless silence pervaded the watching multitude, and nothing was heard amongst the working party on the Anglesea side but the steady tramp of the men at the capstans, the shrill music of the fife, and the occasional order to 'Hold on!' or 'Go along!' But no sooner was the raft seen floating away, and the great chain safely swinging in the air, than a tremendous cheer burst forth from both sides of the Straits....”
[The Bridge Over the Menai Straits, John Cassell's Illustrated History of England, Smith, 7th ed., 1863]