ble stones were found heaped along its sides, of a size suitable for paving.

An interesting locality of boulder rocks was met with at Rawson's mills, town of Van Buren. An excavation in the river bank had exposed a bed of limestone and clay-slate rocks, thickly deposited near the water's edge, to the depth of several feet. The slates were often of two to three feet diameter, of dark color, fissile, and containing iron pyrites.

Marshes or Wet Prairies.

Comprise extensive tracts; they are of generally similar character, being low portions of the sandy openings that have been subjected to an overflow of water for a sufficient period to allow a deposition of muck or peat from vegetable decomposition. This peat supports a growth of wild grass, destined to add annually to its accumulation. Thus what were ponds, become by this process extensive beds of vegetable soil, varying in humidity with the seasons. These beds have a depth of from one to six feet,

and upwards.

Indications are apparent which prove that very many, at least, of these peat marshes had their origin in the labors of the beaver, aided by the natural conformation of the surface. They occupy gently rolling tracts, in which ridges of sandy "openings" and detached prominences or islands of the same are intersected by long bands of marsh. Nearly all the streams of the border townships head in these tracts, and it is easy to conceive how the portions now converted into marsh might have been flooded by the obstruction of those natural channels.

If this view be correct, the practicability of drainage becomes at once established; and such conclusion is verified by actual results.

The following comprise the principal marshes of the county:

About fourteen sections, two-thirds of which are in the town of Hamtramck and the remaining third in Oakland county, are of the character above described; but not more than one-half this extent is actual prairie. This yields an abundant growth of wild hay. The marsh is now in the progress of successful drainage. Á thickness of fibrous peat is disclosed, averaging four feet, succeeded by a subsoil of gray sand, nearly free from aluminous and vegetable matter.

Prairie of similar character occurs in the towns of Greenfield, Redford and Royal Oak. It covers eight sections, one-half of which is in Oakland county. Comparatively a small portion consists of dry openings, and one half bears a dense growth of small tamarac. Its soil varies in depth from three to six feet, and is in many places so charged with water as to be tremulous. It produces large quantities of cranberries.

Prairies of a different character occur in the lower part of the county, over a surface of forty-six sections, of which eighteen are included in the town of Ecorce, eleven in Brownstown, seven in Romulus, and ten in Huron.

Branches of the Ecorce and Brownstown creeks meander this tract. These, flowing with little descent through lines of level prairie, are ramified in every direction, and form a net work or connected chain of marshes over the whole surface. The dry portions consist of sandy plains, frequently but little elevated above the surrounding marshes, and producing a scattered growth of yellow and white oaks. They sometimes assume the form of ridges, which continue unbroken for many rods, and without any uniform direction. The marshy portions, which generally predominate, have a soil of black muck, intermixed with sand washed from the adjoining plains, averaging two to three feet in depth. This is covered by a few inches of light, fibrous peat. Subsoil is sand. In a few instances clay was found approaching the surface, and it undoubtedly underlies at no great depth.

Wild hay is cut on these marshes in considerable quantities. According to reports of the Indians, beavers disappeared from this region thirty years ago. Their numbers previous are said to have been incredible.

Few trials have been made in drainage. A shallow ditch, or even a passage cut through a beaver dam, has in two or three instances effected great improvement. I observed vegetables growing upon a piece thus ditched, and it is said that wheat succeeds well.

This tract is owned mostly by "non-residents." Several untenanted houses gave evidence that a few families who had commenced a settlement have deserted to more favorite spots. Ditching had not been attempted. The expense of this kind of improvement is comparatively small, and I do not doubt that were less than half the ordinary labor in "clearings" bestowed upon a course of drainage, these lands, instead of their present little estimation, might soon be accounted amongst the most fertile in the

state.

In the southeast quarter of range eight east, town of Huron, marshes occupy, it is supposed, two-thirds of the surface. They have a peat soil, averaging two feet, but occasionally much deeper and inclined to bog. Cranberries grow abundantly. Branches of Swan creek meander this tract in such manner as to facilitate drainage; and the comparatively dry character of a large portion will render the cost of ditching moderate.

*Ditches may usually be cut, of three feet wide by two deep, for from two to four shillings per rod; perhaps less. The main ditches of the extensive marshes in Hamtramck, owned by Judge Conant and others, are six feet by four, and cost one dollar per rod.

Smaller marshes occur in the county, though not frequent, and of little general account.

Encroachments of the River and Lakes.

Extensive damage has been occasioned by the unusual height of the lake waters during several past seasons. From the St. Clair to Huron river, the coast, which is mostly gravelly blue clay, with alternations of sand, has been abraded to such an extent, since 1835, as to remove the entire line of coast, where unprotected, several yards to the westward. Along the coast of Hamtramck, above Detroit, scarcely a vestige of the old river road remains. Near Milk river point the waters are said to have advanced inland one hundred and fifty feet within the past two years. Below Detroit the depredations upon the coast have been less severe, but sufficiently so to render a portion of the road below the Ecorce unserviceable and deprive the already narrow turnpike above of several yards of its width. Along the Gibraltar front, at the mouth of the straits, where the bank is from six to ten feet in height, the waters have advanced ten feet inland.

This abrasion of the coast has been in progress not only for the past two or three seasons, but to some extent through the fluctuations of level in the lakes during a much greater term of years. While the configuration of the straits preserves the Canada shore in a great degree from erosion by the current, its whole force is felt upon the western coast; a much greater abrasion being prevented only by the low and shelving character of a large portion.

From the same cause the marshes bordering the shores have been greatly extended. Many acres of former arable land, both in Wayne and Monroe, are now embraced by the waters. Numbers of orchards, the growth of a century, have become a prey to the flood, and families of the old French inhabitants are driven from homes till now occupied from childhood. The United States road from Detroit to Monroe has been rendered impassable at no less than three points, and the travel forced into other and circui

tous routes.

Leaving to an abler pen the investigation of the causes of this unprecedented rise, it may not be amiss to notice, briefly, such remedies as have been tried, or may be proposed to check the devastations occasioned by it. Should those causes continue to operate in maintaining the present elevation of the waters, the subject will become of vast importance to the interests of this portion of our state. Every foot of coast now suffered to waste away, involves a loss much exceeding that already sustained. The inconvenience now felt from the diminished breadth of the river road below Detroit, calls for one of two remedies; either the road

side must be protected by a dock along nearly its whole extent, or a new and broader road must be opened in the rear and beyond such a probable future contingency. The former method, owing to its expense, will, it is presumed, never be resorted to by public authority, nor by individuals to much extent.

Although the erection of docks is undoubtedly the only permanent protection, more simple remedies may to some extent prove of avail. Quantities of brush, strewed thickly along the exposed bank, afford a considerable protection against the direct force of the waves, and also aid, by the retention of the sand and gravel brought up, to form a beach along its foot. A heavy log or fallen tree, placed at right angles to the shore, serves to accumulate a beach, and thus often affords protection.

These remedies are not invariably successful; but they are easily attainable, involve but small expense, and will be properly estimated if they tend to preserve even a small portion of the wealth of the landholder from the devouring wave.

Clay.

Clay suitable for bricks and pottery, is found at numerous places in the county, though the value of much of it is deterioated by the presence of lime. The manufacture of bricks is conducted at several points.

At Springwells a brick yard has been established for several years. The clay used is from the blue clay deposit, and is toIerably free from grit. The sand is taken from a cap or hill lying above the clay with strata of gravel interposed. The bricks find a market at Detroit. About five hundred thousand are manufactured annually, worth five dollars per thousand.

A superior clay for brick is found in the banks of the valley of the Rouge, and several kilns are established in the towns of Springwells and Ecorce. At a yard belonging to Mr. Abial Wood, on the south side of the river, (farm No. 661,) the clay employed is of a light blue color, free from grit. It improves with the excavation. At a depth of six feet, I observed it of a lighter color, sometimes veined with white. About three hundred thousand bricks were manufactued this season.

At a yard of Mr. Wood, on the opposite side, about the same number have been made. This yard has been established three years. The blue clay is used, and is said not to improve with the depth. The overlaying yellow clay is considered inferior. A cap of sand overlies of two to four feet.

Two adjoining brick yards have manufactured about the same number each; an amount this season less than usual, on account of the prevailing sickness.

A fine blue clay appears near the river bank at Flat Rock,

from which brick is made. Its quality is said to be impaired by lime. About five hundred thousand have been burned.

At Morris', three miles above Mt. Pleasant, a brick yard is commenced, clay is said to be of good quality. The yard is on the summit land adjoining the river, at a height of fifty feet.

Two yards are established on the middle branch of the Rouge, in the town of Nankin. At Wilkinson's, near Schwarzburg, clay appears in a stratum running along the bank, and is here two and a half feet thick. Portions contain too much lime to be used with advantage. Good bricks are manufactured of the clay taken from the river bottoms, at Swift's, section eleven.

A bed of clay occurs in town of Plymouth, section four, from which bricks and earthern ware are manufactured. It consists of strata of the blue and yellow varieties, underlying probably eight acres, with an average thickness of four feet. A cap of sand, of two feet thickness, overlying, is used in the manufacture. Sand and gravel underlie the bed of clay, which are unfit for use from the lime contained. The bricks are of good quality; one hundred thousand were made this season, worth five dollars per thousand. The pottery ware receives a good glaze, and is durable.

A bed of clay exists west of Plymouth corners, section twenty seven. It is supposed to cover eighty acres. Considerable lime is contained; five hundred thousand bricks are made from it each season.

A bed of fine blue clay exists on section eleven. The above were the only deposites observed in this township.

1

Blue clay appears at the surface in the town of Canton, which is free from lime.

In the town of Huron a fine blue clay underlies the low lands bordering Swan creek, at small depth, and frequently comes to the surface.

The blue and yellow clays make their appearance at every bluff along the Huron. They are in general very marly, and seldom free from grit. A kiln was erected in a ravine of Woods' creek, section thirty-six, Van Buren, but the clay proved so calcareous that the works were abandoned.

Limerock.

The great limerock formation, upon which the clay deposites of the county rest, makes an outcrop, or appearance at the surface, through the townships of Monguagon and Brownstown. It forms the bed of the strait near its mouth, as well as a foundation to the islands.

The most easterly point at which the rock appears above the level of the water, is at Stony island. This is wholly constituted