A memorandum in Trevithick's writing, apparently a diary, says:-- "From where we returned our mules to the place where we commenced to make our rafts and boat was eleven days' journey, a distance of 50 or 60 miles. The first and second days after parting with the mules we passed some soft ground, with three or four rivulets of water in narrow vales, about 10 miles on the side of the decline of the high ridge on our left. It could easily be made passable for mules, as the bad places where they could not travel did not exceed two or three miles; and had we kept a little more to the left above the soft ground, probably they could have passed. The next bad place was about a mile after the second pass across the San José River, being a very deep and abrupt vale. Had we never passed the San José River, but left it on our right hand, the road would have been much shorter, and we should have avoided this deep vale, and also the three other vales, and their three rivers of Montelegre, Juan Mora, and Ajerbi. They were, however, small, not more than half the leg in water, which is a proof that their source was not above 10 miles off and must have originated in the side of the high ridge on our left. None of the vales were impassable to mules, except that between the second passing of the river San José and the river Montelegre, which was about a mile, and might be made passable for mules by a diagonal road to be made in the side of the hill a little higher up. "Only five or six miles of road would require to be made for mules on the whole of the way we came, to where the river Serapique is navigable. We observed that we should have avoided those vales by passing a few miles more to the left, where we saw one continued high ridge running from the highest ridge of the continent, commencing at the volcano and terminating in a point near to where the Serapique River is navigable. "On a regular decline for perhaps 7000 or 8000 feet in height, down to near sea-level, which would in that distance have given a fall of about half an inch in a yard, four men in ten days would make, I have no doubt, this ridge passable for mules on a regular descent to where the Serapique River is navigable. I have no doubt if we could have spent one week more on our journey we might have passed mules the whole distance with us. To carry machinery from where the Serapique is navigable to the mines is about one-third farther than from the port of Arenas on the south, on which the carriage is two dollars per mule load; three dollars might therefore be charged per mule from the Atlantic side, a much less cost than by way of Matina, or by going around Cape Horn. It would give a speedy communication and a great accommodation to the province of Costa Rica, which I doubt not would gladly contribute to its making.