particularly described by Mr. Hall, are, beginning at the apex of the Helderberg, chertz limestone, neutral colored sandstones, fossilliferous limestone, graywacke, sedimentary, horizontal slate, or graywacke slate, and argillite, This stratification, first noticed, it is believed, by the late Dr. T. Romeyn Beck, is exposed to view wherever the streams of the county have worked their beds immediately into it.

The city of Albany rests on the edges and top of the terraceous blue clays and their associated sand strata. I do not know the height of the foundation of the Capitol, above the Hudson river. It can not be less than 140 feet, and the stiff escarpment of the clay beds cut down, at this point, preparatory to the building of the Capitol, were probably 18 or 20 feet, This terraceous clay is covered with a mantel or plateau of diluvial sand, which at the assumed elevation, extends northwestwardly from the Hudson to the valley of the Mohawk. It is sixteen miles from river to river, by about half the distance in breadth, where it is merged in the arable uplands. The area of this sand plain, sometimes called the Honicroisa tract, can not be less than one hundred and twenty square miles. It is not all equally arid, equally barren and unfit for every species of agriculture; but it is, perhaps, to the impeachment of our agricultural acumen, a tract of remarkable dimensions, and that lying in the heart of the state, abstracted from the area of husbandry. Originally covered with a magnificent forest of the pinus resinosa and shrubbery peculiar to arenaceous plains, the surface is now well nigh denuded: the winds have insinuated into the sides of hills, creating a species of dunes.

Across this plain, in their journeys from the West, laid the ancient path of the Iroquois, who, impressed by its peculiarities of soil and growth, whichever way they crossed it, called it, in their expressive language, the Skenektadea * a term which has been applied, with

The elements of this compound term are the word ske, meaning through or among; Nek, a pine tree; ta or dah, a formation of rock or hard soil, and dea, a plain or valley. The latter termination is heard in Tahopatatea, the Iroquois name of the Hudson in Canada, &c.

modifications, at successive periods, to each of the cities situated on its eastern and western verge.

This mantle of sand rests, throughout its entire extent, upon the terraceous blue capitoline clay. Rains and atmospheric moisture speedily sink through it, till arrested by its impervious aluminous basis. The effect of this arrangement has been to convert the strata into a vast filtering apparatus, by which the surface waters are at the same time, purified and cooled, and find their outlet, on the surface of the clay beds, into the nearest streams. But this filtering process has had another striking effect on the mineral physiognomy of the central and southeastern parts of the county. The trickling of springs on the line of the aluminous strata, has carried along the quartzose grains of sand, causing the superincumbent beds to cave in. The result of this action has been to cut up the surface of the plains into gulfs, gorges and minor valleys. By throwing the arenaceous on the clay beds, a new soil is produced very favorable to the growth of deciduous trees. These gorges and sub-valleys are therefore filled with hard wood species, while the arid and dry plains bear only pines. They furnish cool retreats for every species of animated nature, during the heats of the day, and it is from the close and vigorous growth of the foliage, in these numerous gorges, that the wolf still maintains his position, and defies the farmer and his sheep-folds from these inaccessible positions.

It is by the union of several of the outlets of these spring gorges of the pine plains, that the Honger kill is formed. Small in its volume, it is of unsurpassed purity and unfailing supply and flows with a force sufficient to sink its channel through the deep clay stratum, and enter its recipient, the Tawasentha, or Norman's kill, through the boulder and pebble drift. Like other streams of primary or secondary importance, the banks of this streamthe ample space left for its outflow, and the elevation of its bordering hills, force the mind, on one of two conclusions, either that fluviatile action was, at former periods of comparatively immense force, or, that the time consumed

by the present feeble action on the earth's surface must have been very great. Feeble as the action of the stream is, it has been sufficient to reveal a formation of red sandstone, which, apparently, underlies the under Helderberg series of graywacke and slates, and the upper series of fossiliferous limestone, and its superimposed porous and marly horizontal new sandstones.

This disclosure was made in a depressed part of the Honger kill valley, in the course of excavations made in the heavy embankment constructed by the Western turnpike company, in crossing that valley. The rock, in colors and grain, resembles the Piermont or Haverstraw sandstones of the lower Hudson. It is perhaps, characteristically less quartzose and compact. It is also less apyrous, as was tested by placing a massive block, in the high heat of a glass burner. Another locality of the same rock, penetrates through the soil, in the same valley, at a higher point. * These localities are at the now decayed manufacturing village at Hamilton, within about a mile from the entrance of the stream into the Norman's kill, or Tawasentha. Geologically, but not topographically, the Honger kill sandstone underlies the

state.

The deepest cutting into the geological column of the county, is made by the Tawasentha. This stream in its western fork, the Roga or Mad creek, originates on the Helderberg range. In passing through the series of newer sandstones and limestones and graywackes it lays bare the succession of rocks, and hurries with a rapid channel to its junction, with the Swarte, or Black, and the Tiergaea, or north-east branch. Reinforced by these tributaries, it sweeps its way through the alluvial coverings, for the Hudson. In its progress it sinks its level quite through the graywacke, and deeply into the Tawa. sentha slate, which is a sedimentary or graywacke slate.

*This latter locality was pointed out to me, as an anomaly, by the late John Schoolcraft, Jr., Esq., of Hamilton Village, or Guilderland.

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At the rapids of the Globe mills, or French's and other parts of Guilderland, this rock stands in perpendicular facades, from eighty to, perhaps, a hundred and twenty feet high. They are least prominent opposite the Boulder banks at Mulberry hill, near the entrance of the Honger kill. At lower points of its course, the valley assumes a greater expansion; and its precipices have suffered more from the degradations of elemental action. The river finally enters the Hudson, two miles south of the city, between the ancient Iroquois cemetery of Tawasentha and Kiddenhooghten.

*This curious natural mound, or hillock, is connected with the diluvial formation, by a narrow rock, or peninsula. It was a spot sacred to sepulture, from the earliest time; and furnished them a natural cognomen for the stream. There is no object of higher antiquarian interest in the vicinity, and it is worthy of municipal care.

THE CITY'S ANCIENT RAVINES.

Three considerable streams of water, which anciently traversed the city, have within the memory of many inhabitants, been converted into sewers, namely, the Foxen kill, the Rutten kill and the Bever kill. The Foxen kill, when the city was first settled, and for a long time after, afforded abundance of fish. It ran outside of the stockades, which for a great many years formed the northern boundary of the city. It is but little more than a quarter of a century since it was crossed by a bridge in North Pearl street, near Orange.

The Rutten kill was a lesser stream, having its source above Lark street, but which sent down a formidable volume of water in times of freshet. The inhabitants of the upper end of Beaver street, have an inkling of what It may have been when they are refreshed by a heavy rain storm. This also was a never-failing brook, stored with fish, and was the only one that came within the old city walls. Passing down the Hudson street ravine, it crossed Pearl street where the Congregational church stands, and entered the river a few feet below State street. In the oldest map of the city 1676, (see Annals vol. iv, p. 200), a brug marks the spot where it crossed the street now called Broadway. The city records frequently allude to these bridges. In January, 1701, we find the following entry:

"It is further concluded since ye Bridges by Coll. Schuyler's doth decay, that Mr. Roseboom, Hendrik Oothout and Harpert Jacobse vizite ye same, and make returne ye next court what is required to be repaired."

A meeting was held on the next day, when the following report was made:

"Relating the bridge at Coll. Schuyler's, ye gentlemen yesterday appointed to vizite ye same do return that it requires to be repaired with one oak logg, of 17 foot, 12