Trevithick also appears to have been among, if not the very first to employ the expansive principle of steam. In the year 1811-12 he erected a single-acting engine of 25 inches cylinder at Hull-Prosper in Gwithian, with a cylindrical boiler, in which the steam was more than 40 lbs. on the square inch above atmospheric pressure; and the engine was so loaded that it worked full seven-eighths of the stroke expansively. In this he seems to have preceded Woolf by several years. It is also stated by Mr. Gordon in his 'Treatise on Elementary Locomotion,' that Trevithick was the first to turn the eduction-pipe into the chimney of the locomotive to increase the draught.[45] We now come to the most romantic and stirring period of Trevithick's career. In 1811 M. Uvillé, a Swiss gentleman at that time living in Lima, came to England to see if he could procure machinery for clearing the silver mines, in the Peruvian mountains, of water. Watt's condensing engines were, however, of too ponderous a nature to be transported over the Cordilleras on the backs of the feeble llamas, and Uvillé was about to give the matter up in despair, when, on the eve of his departure from this country, he chanced to see a small working model of Trevithick's engine in a shop window near Fitzroy Square. This model he carried out with him to Lima, and had the satisfaction of seeing it work successfully on the high ridge of the Sierra de Pasco. Uvillé now returned to England to procure more engines of the same kind, but he was a second time almost forced to give the matter up; for Boulton and Watt, the most distinguished engineers of their time, assured him that it was impossible to make engines of sufficient power and yet small enough to be carried over the Andes. Fortunately, however, Uvillé at this point met with Trevithick himself, and was enabled to make such arrangements with him as resulted in the embarkation, during September 1814, of three engineers and nine of Trevithick's engines. On landing at Peru, Uvillé and his charge were received with a royal salute, and in due time the engines, which had been simplified to the greatest extent, and so divided as to form adequate loads for the weakly llama, were safely carried over precipices where a stone may be thrown for a league. An engine was soon erected at Lauricocha, in the province of Tarma, which successfully drained the shaft of the Santa Rosa mine, and enabled working operations to be recommenced. During the year 1816 Trevithick, hearing of this success, gave up family and fortune and embarked for South America. On landing he was received with the highest honours; all Lima was in a state of excitement, which rose to a still greater pitch, when it was found that his engines, by clearing the mines of water, had doubled their produce and increased the coining machinery sixfold. Trevithick was created a marquis and grandee of old Spain, and the lord warden of the mines proposed to raise a silver statue in his honour.