but a precipitous escarpment on the southeast. The Gothics are like a steep wedge standing on its base, and tapering from all four sides of the base to the ridge. Whiteface is a long sharp ridge, steep if not actually precipitous on each side, and leading up to a peak at the southwestern end. Some buttresses run out from the ridge and make beautiful cirques on its flanks. Hurricane, when viewed from the east, resembles a sharp volcanic cone; from the west it is flat. There are several, of which Dix is the highest example, which, like Vesuvius, have a small conical summit set upon a large mountainous base. Nippletop is a rather favorite name in the local nomenclature of the inhabitants. There are several smaller mountains which have the outlines of a steep haystack when viewed from certain directions, and their precipitous sides and doming tops fix the eye at once. Yet they may each be a ridge when seen from the opposite. One very exceptional peak, quite inappropriately called Sugarloaf, near Hulett's on Lake George, is a circular mesa, with a flat top several acres in area and dropping with steep sides to the lake slope below. It resembles a round fort or old-time castle, such as St. Angelo, across the Tiber from Rome, or Castle William on Governor's Island in New York Harbor. It is due to flat foliation in the gneisses combined with intersecting vertical joints. Not a few other mountains, although of very irregular shapes at the base, yet have flat tops of considerable area. Their level summits appear to be the surviving remnants of some old-time peneplain now faulted into relief, as will be later explained.

The plateau portion, which makes up practically the western half, is not absolutely flat, but is more or less diversified with low hills and intervening broad valleys. Occasional summits give views of moderate extent, but no elevations can properly be called mountains, and the general term plateau is most expressive. It may well be the remnant of an old peneplain, perhaps the important one widely developed in Cretaceous time in the east.

The Valleys. The mountains can not all be described without parallel and complementary reference to the valleys, and in discussing the latter the causes which have led to the production of the former may best be mentioned.

At least two marked and contrasted types of valleys may be distinguished. There is an old series which in part probably dates back even to Precambrian time. In the eastern mountains the cause of their excavation is oftentimes obviously the presence of relatively soft and easily eroded limestone in the series of gneisses. In several notable cases the Potsdam and even later Paleozoic formations can be traced by the remaining outliers some miles into the old crystallines, and although subsequent faulting has exercised its modifying and disguising influence, yet it has appeared to several observers that the old

depressions were recognizable. The old valleys have gentle slopes and wide expanses. Their contours are softened down and the whole physiographic expression is one which suggests long-continued erosion and maturity of form. In studying out these relations, one has also to eliminate as far as possible the mask of glacial drift which is everywhere in evidence. The valleys of the old system run in their most marked development east and west, and north and south. Several of them are occupied to-day by some of the largest streams and lakessuch as Schroon lake, the southern third of Lake George, parts of the Hudson Valley and several tributary to Lake Champlain. One half of an old valley will often remain with characteristically gentle slope and mild topography, while the other half of the depression will consist of the steep precipices of the next type. And as the second type has been superimposed upon the first, the observer is often forced to trace the former out despite its disguises and modifications.

The second type of valley is obviously the result of faulting, and of faulting that is of no great geological antiquity. The sides and steep escarpments and the depressions may have all the characteristics of a "Graben-senkung, or of a fjord, if the latter can be imagined away from the sea. In the southeastern portion of the mountains as well as in the interior, three pronounced sets of fault escarpments may be recognized and plotted. The most marked one is northeast, and to it is due the general northeast and southwest trend of the mountains. The topographic maps, and still more the relief model prepared by

E. A. Howell, show this in all desirable clearness. Along the shores of Lake Champlain the ridges come in one after another from the southwest, making the western shore of the lake a series of bays with bold intervening headlands. The central portion of Lake George, where the wildest and most picturesque scenery is found, is another example. Precipitous escarpments characterize the shores, while mountains of rugged outline shut in the observer. In the interior these characters appear on an even grander scale. The Lower Ausable lake is a Graben; Avalanche lake, one of the sources of the Hudson, has cliff's so steep that the traveler must take to a boat to find a passage. In Wilmington notch, as also in Indian pass, cliffs hardly less than a thousand feet, front the traveler.

A second but less strongly developed series of faults runs northwest and southeast and is the cause of many cross breaks at right angles with the set last mentioned. They serve to block out the individual mountains amid the general northeast trend of the ridges, and are responsible for innumerable little cross-passes which are found on all the summits. In the high mountains, the little cross-passes almost always have a well-defined bear or deer trail following them through. They serve also to develop sharp shoulders in the precipices of the first type and to give the shores of a lake a very serrated outline. In the Mount Marcy and Elizabethtown quadrangle they, with the first set, have occasioned the interesting lattice-shaped' drainage noted by Professor Brigham some years ago. The little streams flow

FIG. 7. THE CASCADE LAKES, BETWEEN THE KEENE VALLEY AND LAKE PLACID-illustrating

FIG. 8. DEER'S LEAP, AN ESCARPMENT ON LAKE GEORGE-produced by intersecting north

east and northwest joints, or perhaps faults-and much freshened by the ice of the Glacial epoch.

down moderate slopes from the northwest, against high and sparsely wooded precipices on the southeast and join larger streams which flow northeast or southwest. When a wide area is studied, it is only the older and still surviving east and west or north and south valleys which break up this lattice-like regularity.

In less frequent occurrence than the northeast and northwest fault breaks, minor ones ranging nearly due north may be recognized-but they do not exercise so important an influence on the general relief.

The three systems of faults have in some instances led to great single precipitous escarpments suggesting that the movement was chiefly confined to one single plane, but it is much more common to find the fault a compound one. That is, a very steep mountain face will consist of a series of small escarpments, each with a bench at its foot. These benches make terraces, and on Lake George one can easily see, even when the mountain is thickly forested, that the trees are growing in pronounced rows with thinner lines of vegetation between. A mountainside may thus look like a gigantic series of furrows, as is true of the ridge from Black Mountain to Elephant Mountain. Where the faults cut across a projecting shoulder the terraces go up one side and down the other like a series of lunettes. Forest fires and the lumberman's axe, while destroying much of the beauty, have yet brought out these features with striking emphasis, and when the light intensifics the relief with shadows they appeal to the observer in the strongest way. The narrow ridge between Lake George and Lake Champlain contains some of the roughest country in all the Adirondack region.

The faults and their escarpments were doubtless much freshened up by the Labradorcan ice-sheet which plucked away from their faces the loose rock, sheeted by the parallel faults. In this way the relief was heightened during the Glacial epoch, and its freshness and youth still remain to us, but the faults preceded the ice and were the great governing factors. Thus far no evidence of post-glacial faulting has been observed.

On the south side of the mountains the faults run out in a striking way into the overlapping Paleozoic areas and have been traced as much as thirty or forty miles. One famous one causes the Precambrian rocks on the west to abut sharply for thirty miles against the Cambrian and Ordovician strata, forming an escarpment which faces east. After the Precambrians have disappeared below the Paleozoics for two miles, they rise again into view at the pass called the 'Needles,' where the Mohawk river, the Erie Canal and the New York Central and West Shore Railways find a way close together fifty miles west of Albany. Another is responsible for the Precambrian outlier of Little Falls, recently described by Professor H. P. Cushing. The displacements ex