On opening the great arch at London Bridge, by throwing two arches into one, and the removal of a large pier, the excavation, around and underneath the sterlings of that pier, was so considerable, as to put the adjoining piers, that arch, and eventually the whole bridge, in great danger of falling. The previous opinions of some were positive, and the apprehensions of all the people on this head were so great, that many persons would not pass over or under it. The Surveyors employed were not adequate to such an exigency. Mr. SMEATON was then in Yorkshire, where he was sent for by express, and from whence he arrived in town with the greatest expedition. He applied himself immediately to examine the bridge, and to sound about the dangerous sterlings, as minutely as he could. The Committee of Common Council adopted his advice; which was, to re-puchase the stones of all the City Gates, then lately pulled down, and lying in Moorfields, and to throw them pell-mell, (or piece perdu,) into the water, to guard these sterlings, preserve the bottom from further corrosion, raise the floor under the arch, and restore the head of water necessary for the water-works to its original power ; and this was a practice, he had before, and afterwards adopted on other occasions. Nothing shews the apprehensions of the bridge falling, more, than the alacrity with which his advice was pursued : the stones were re-purchased that day ; horses, carts and barges were got ready, and the work instantly begun, though it was Sunday morning. Thus Mr. SMEATON, in all human probability, saved London Bridge from falling, and secured it till more effectual methods could be taken.
Life of Mr John Smeaton, in Reports of the Late John Smeaton: F. R. S., Made on Various Occasions, in the Course of His Employment as a Civil Engineer, 1812