In the mean time Mr. Stephenson and his assistants were diligently occupied in making the necessary preliminary arrangements for the conduct of the traffic against the time when the line should be ready for opening. The experiments made with the object of carrying on the passenger traffic at quick velocities were of an especially harassing and anxious character. Every week, for nearly three months before the opening, trial trips were made to Newton and back, generally with two or three trains following each other, and carrying altogether from 200 to 300 persons. These trips were usually made on Saturday afternoons, when the works could be more conveniently stopped and the line cleared. In these experiments Mr. Stephenson had the able assistance of Mr. Henry Booth, the secretary of the Company, who contrived many of the arrangements in the rolling stock, not the least valuable of which was his invention of the coupling screw, still in use on all passenger railways. At length the line was finished, and ready for the public ceremony of the opening, which took place on the 15th September, 1830, and attracted a vast number of spectators. The completion of the railway was justly regarded as an important national event, and the opening was celebrated accordingly. The Duke of Wellington, then Prime Minister, Sir Robert Peel, and Mr. Huskisson, one of the members for Liverpool, were among the number of distinguished public personages present. Eight locomotive engines, constructed at the Stephenson works, had been delivered and placed upon the line, the whole of which had been tried and tested weeks before, with perfect success. The several trains of carriages accommodated in all about six hundred persons. The procession was cheered in its progress by thousands of spectators—through the deep ravine of Olive Mount; up the Sutton incline; over the great Sankey viaduct, beneath which a great multitude of persons had assembled,—carriages filling the narrow lanes, and barges crowding the river; the people below gazing with wonder and admiration at the trains which sped along the line, far above their heads, at the rate of some 24 miles an hour.