=The birth of volcanoes.=—To confirm the impression that the formation of the volcanic mountain is in reality a secondary phenomenon connected with eruptions, we may cite the observed birth of a number of volcanoes. On the 20th of September, 1538, a new volcano, since known as Monte Nuovo (new mountain), rose on the border of the ancient Lake Lucrinus to the westward of Naples. This small mountain attained a height of 440 feet, and is still to be seen on the shore of the bay of Naples. From Mexico have been recorded the births of several new volcanoes: Jorullo in 1759, Pochutla in 1870, and in 1881 a new volcano in the Ajusco Mountains about midway between the Gulf of Mexico and the Pacific Ocean. The latest of new volcanoes is that raised in Japan on November 9, 1910, in connection with the eruption of Usu-san. This “New Mountain” reached an elevation of 690 feet. [Illustration: FIG. 88.—View of the new Camiguin volcano from the sea. It was formed in 1871 over a nearly level plain. The town of Catarman appears at the right near the shore (after an unpublished photograph by Professor Dean C. Worcester).] As described by von Humboldt, Jorullo rose in the night of the 28th of September, 1759, from a fissure which opened in a broad plain at a point 35 miles distant from any then existing volcano. The most remarkable of new volcanoes rose in 1871 on the island of Camiguin northward from Mindanao in the Philippine archipelago. This mountain was visited by the _Challenger_ expedition in 1875, and was first ascended and studied thirty years later by a party under the leadership of Professor Dean C. Worcester, the Secretary of the Interior of the Philippine Islands, to whom the writer is indebted for this description and the accompanying illustration of this largest and most interesting of new-born volcanoes. As in the case of Jorullo, the eruption began with the formation of a fissure in a level plain, some 400 yards distant from the town of Catarman (Fig. 88). The eruption continued for four years, at the end of which time the height of the summit was estimated by the _Challenger_ expedition to be 1900 feet. At the time of the first ascent in 1905, the height was determined by aneroid as 1750 feet, with sharp rock pinnacles projecting some 50 or 75 feet higher. =Active and extinct volcanoes.=—The terms “active” and “extinct” have come into more or less common use to describe respectively those volcanoes which show signs of eruptive activity, and those which are not at the time active. The term “dormant” is applied to volcanoes recently active and supposed to be in a doubtfully extinct condition. From a well-known volcano in the vicinity of Naples, volcanoes which no longer erupt lava or cinder, but show gaseous emanations (_fumeroles_) are said to be in the _solfatara_ condition, or to show _solfataric_ activity.