Petrarch is not the only great name that links the Renaissance to the birth of mountaineering. That versatile genius, Leonardo da Vinci, carried his scientific explorations into the mountains. We have already mentioned his great picture of storm and thunder among the hills, one of the few mementos that have survived from his Alpine journeys. His journey took place towards the end of the fifteenth century. Little is known of it, though the following passage from his works has provoked much comment. The translation is due to Mrs. Bell: “And this may be seen, as I saw it, by any one going up Monboso, a peak of the Alps which divide France from Italy. The base of this mountain gives birth to the four rivers which flow in four different directions through the whole of Europe. And no mountain has its base at so great a height as this, which lifts itself above almost all the clouds; and snow seldom falls there, but only hail in the summer when the clouds are highest. And this hail lies (unmelted) there, so that, if it were not for the absorption of the rising and falling clouds, which does not happen more than twice in an age, an enormous mass of ice would be piled up there by the layers of hail; and in the middle of July I found it very considerable, and I saw the sky above me quite dark; and the sun as it fell on the mountain was far brighter here than in the plains below, because a smaller extent of atmosphere lay between the summit of the mountain and the sun.” We need not summarise the arguments that identify Monboso either with Monte Rosa or Monte Viso. The weight of evidence inclines to the former alternative, though, of course, nobody supposes that Da Vinci actually reached the summit of Monte Rosa. There is good ground, however, for believing that he explored the lower slopes; and it is just possible that he may have got as far as the rocks above the Col d’Ollen, where, according to Mr. Freshfield, the inscription “A.T.M., 1615” has been found cut into the crags at a height of 10,000 feet. In this connection it is interesting to note that the name “Monboso” has been found in place of Monte Rosa in maps, as late as 1740.[1]