of the mountain is from a half mile to a mile and a half, the western slope being quite gentle.  In length it extends from Bergen Point below Jersey City to Haverstraw, and then westward in all 48 miles, the middle portion being merely a low ridge.  The lower half of the ridge on the river side is a sloping mound of detritus, of loose stones which has accumulated at the base of the cliff, from its weathered and wasted surface.

“Viewed from the railroad or from a steamboat on the river, this lofty mural precipice with its huge weathered masses of upright columns of bare rock, presenting a long, straight unbroken ridge overlooking the beautiful Hudson River, is certainly extremely picturesque.  Thousands of travelers gaze at it daily without knowing what it is.  This entire ridge consists of no other rock than trap traversing the Triassic formation in a huge vertical dike.  The red sandstone formation of New Jersey is intersected by numerous dikes of this kind, but this is much the finest.  The materials of this mountain have undoubtedly burst through a great rent or fissure in the strata, overflowing while in a melted or plastic condition the red sand-stone, not with the violence of a volcano, for the adjoining strata are but little disturbed in position, although often greatly altered by the heat, but forced up very slowly and gradually, and probably under pressure.  Subsequent denudation has laid bare the part of the mountain now exposed along the river.  The rock is columnar basalt, sometimes called greenstone, and is solid, not stratified like water-formed rocks, but cracked in cooling and of a crystalline structure.  Here is a remarkable but not uncommon instance of a great geological blank.  On the east side of this river the formations belong to the first or oldest series of Primary or Crystalline rocks, while on the west side they are all Triassic, the intermediate Cambrian, Silurian, Devonian and Carboniferous formations being wanting.  This state of things continues all along the Atlantic coast to Georgia, the Cretaceous or Jurassic taking the place of the Triassic farther south.

* * *

  Like thine, O, be my course—­nor turned aside,
  While listening to the soundings of a land,
  That like the ocean call invites me to its strand.

  Mrs. Seba Smith.

* * *

“Montrose to Cornwall.  This celebrated passage of the Hudson through the Highlands, is a gorge nearly 20 miles long from 3 miles south of Peekskill to Fishkill, and is worn out of the Laurentian rocks far below mean tide water.  The hills on its sides rise in some instances as much as 1,800 feet, and in many places the walls are very precipitous.  The rock is gneiss, of a kind that is not easily disintegrated or eroded, nor is there any evidence of any convulsive movement.  It is clearly a case of erosion, but not by the present river, which has no fall, for tide water extends 100 miles up the river beyond the Highlands.  This therefore was probably a work mainly performed in some past period when the continent was at a higher level.  Most likely it is a valley of great antiquity.