But the "human factor" is not the only element of nature with which railway management has to contend. Another, not less serious in its potential consequences, was brought to mind in sinister fashion a few years later, when, during the winter storms of 1868, the Severn and its tributaries rose in flood with such alarming rapidity that the driver of an early morning goods train from Machynlleth to Newtown found, as he ran down the long decline from Talerddig past Carno, that the water was washing over the footplate of the engine, and nearly put out the fire. He naturally bethought him of the wooden bridge over the Severn at Caersws, but, after, careful examination, it was safely crossed. On the return journey, however, the bridge was being carefully approached once more, when, in the dim dawn of a February morning, the engine suddenly toppled-over the embankment abutting on the structure. The floods had washed away the earthworks, though the beams of the bridge itself held fast, and driver and fireman were killed. Word was sent to Oswestry and Aberystwyth, and in the first passenger train from the latter place Capt. Pryce, one of the directors, and Mr. Elias, the traffic manager, were travelling to the scene of the disaster, when it was discovered that another bridge, near Pontdolgoch, was giving way under pressure of the torrent, and the train, crowded with passengers, was only held up just in time to avert what could not have failed to prove a catastrophe far more tragic in extent. Wild rumours quickly spread concerning the cause and nature of the actual mishap, it being freely stated by sensation-mongers that the Severn bridge had collapsed; but Mr. David Davies, who had been its builder and was now a director of the Company, was able to show that, despite the exceptional strain on the construction, the bridge had resisted the force of the flood and was as firm as ever. Wooden bridges, however, have now had their day, and in recent years have, in all important cases, under the enterprising supervision of Mr. G. C. McDonald, the Company's engineer and locomotive superintendent, been replaced with iron girders, to the undisguised regret of some old-fashioned believers in the efficacy of British oak!