PATAGONIA 155 Viedma only is thoroughly known ; it was ex- plored in October, 1874, by Lieut. Feilberg of the Argentine navy, who found it to be 27 m. long and 100 m. in circumference, with a west- ern drainage to the Pacific 32 m. distant. The explorer reached it by the Santa Cruz, and on his return descended the river (which has a current of 6 m. an hour) to Port Santa Cruz at the mouth in 26 hours. The Rio Gallegos flows into the Atlantic at the port of the same name, in lat. 51 50' S. Some of the lagoons in the north are not perennial, but disappear on the subsidence of the floods at the end of the rainy season. The geology of Patagonia is at once simple and interesting. From the Rio Colorado, in the Argentine pampas, south- ward almost to lat. 51, extends one great de- posit including many tertiary shells, all appa- rently extinct, the most common of which is a colossal oyster often a foot in diame- ter. Overlying these beds, the thickness of which at Port San Julian is over 800 ft., is a peculiar soft stone, really pumiceous, though including gypsum and somewhat resembling chalk, and one tenth of whose bulk is com- posed of infusoria, among which last Ehren- berg discovered 30 oceanic forms. The white beds are everywhere capped by a mass of gravel, forming probably, according to Dar- win, one of the most extensive beds of shin- gle in the world. At the Santa Cruz river it reaches to the foot of the Andes, the thickness of the stratum half way up that river being over 200 ft. ; and it probably extends every- where to that cordillera, whence have been derived the well rounded pebbles of porphyry ; thus its mean breadth may be computed at 200 m., and its mean thickness at 50 ft. The whole land from the basin of the Eio de la Plata to Tierra del Fuego has been raised in mass, to a height varying between 300 and 400 ft., within the period of the now exist- ing sea shells; the old and weathered shells on the surface of the upheaved plain still par- tially retain their colors. The upward move- ment has been interrupted by at least eight long periods of rest, during which the sea ate deeply and uniformly into the land, form- ing at successive levels the rows of terraced escarpments. The lowest of these step-like plains is 90 ft. high, and the highest near the coast 950 ft. The plain beyond Lake Viedma, at the foot of the Andes, slopes up to an ele- vation of 3,000 ft. At Port San Julian, in some red mud capping the gravel on the 90 ft. plain, Darwin found half a skeleton of the macrauchenia Patachonica, a remarkable quad- ruped, as large as a camel; and Capt. Sulli- van of the British navy has since discovered, imbedded in regular strata on the banks of the Rio Gallegos, numerous large fossil bones, and some smaller ones, presumed to have be- longed to an armadillo. The middle portion of the straits region, from Peckett's harbor to Port Gallant, is mostly of secondary forma- tion, as far as determined by Mr. Pourtales, who visited the country during the Hassler ex- pedition (1871-'2), the coal of Punta Arenas (Sandy Point) being cretaceous. The moun- tains of the west are for the most part com- posed of primitive rock, immense fragments of which are numerous around the upper course of the Santa Cruz. According to Dar- win, it would be possible to prove that the bed of that river was once the bottom of a strait here joining the Atlantic and Pacific oceans, like that of Magellan. The mineral resources of Patagonia, though supposed by geologists to be comparatively extensive, are imperfect- ly known. Gold was found in 1874 in the region of the Gallegos and Santa Cruz rivers, and near Sandy Point ; but mining operations begun in that year were shortly suspended. Coal is abundant in Brunswick peninsula, though but small quantities have hitherto been extracted. Some diamonds have been dis- covered in the Gallegos river, and pronounced to be similar to those of Brazil. The climate in the north is extremely cold in winter and warm in summer ; and it is very dry, there being often no rain during nine months. In the south there is more moisture; the rainy and windy seasons are spring and summer; the remainder of the year is characterized by calm, interrupted only by light winds. Thun- der is not heard oftener than once in five years. Smallpox is unknown ; rheumatism is com- mon; and the climate is in general remark- ably salubrious. One of the striking charac- teristics of Patagonia is the similarity of the productions throughout, with the single excep- tion of the straits region. The same stunted plants are everywhere to be met with on the arid shingly plains, and the same spiny shrubs in the valleys. Some thorn-bearing shrubs oc- cur likewise in the north, where, not a tree being seen, they form, with salt pools here and there, the only relief to the dreary monotony of the grass-covered plains. In the east the vegetation consists of grasses and a few legumi- nous and composite plants and shrubs, with sweet berries of various kinds. In the south the forests present four species of trees : two beeches, the antarctic (fagm antarctica) and the evergreen (F. letuloides) ; the Winter's bark (drimys Winteri), known for the stimu- lant tonic properties of its aromatic bark ; and the libocedrus tetragona, akin to the Chilian tree furnishing the valuable alerce timber. Shrubs and climbers abound in the thickets, the ornamental species including the Fuchsia, Desfontainea, Perrottetia with small globular berries, philesia with its bell-shaped, rose-red, waxy flowers, and many others. Nearly all the species of the Patagonian flora are also indigenous to Chili, and are found in every part of the moist country from the north of the republic to Magellan straits. Ferns, moss- es, and lichens are found in great abundance ; and among the marine weeds should be men- tioned the gigantic macrocystis pyrifera so common in the straits and on the W. coast, and
