fissile. Limerock is met with, in the same range, at not less than four places, in the township of Bedford. In the bed of Bay creek a small quarry has been opened.

Near the centre of the township it appears twice over surfaces of two-thirds a square mile. These have been penetrated several feet, and are found to consist of a very siliceous rock, composed of an aggregate of grains of quartz cemented by lime. The upper portions, which lie in loose masses, are calcareous, and are alone suitable for burning.

At the southwest corner of section thirty, limerock appears at the surface and in the bed of Halfway creek. This continues at intervals for a mile west, and in a southwest direction, following Ottawa creek, to Whiteford, in Ohio. It underlies the intermediate spaces at a depth probably not exceeding five feet. A continuation of the ledge may also be traced north, along the whole eastern border of township of Whiteford. The upper portions only could be observed, which appeared to be a pure, compact limestone.

No fossils were found in this range, except Terebratula, at Newport and Stony point.

Another range or series of outcrops passes through the centre of the county, in a direction parallel to the former. It must be considered as the overlapping edge of a portion of the limerock formation, superimposed upon that whose outcrop forms the range first mentioned. This portion of the formation includes several strata of a very siliceous character, approaching in several instances, almost to pure sandrock.

Stone of this description makes its appearance six miles northwest from Monroe, and was traced over a surface of one half a square mile. It disintegrates readily, where exposed, into a pure siliceous sand, which may be seen to be composed of well formed quartz chrystals. Where not discolored by oxides of iron, it is of a pure white.

Associated with this stratum is a gray siliceous limestone, which is fossiliferous.

A similar sandrock appears in the bed of the Raisin, at low water mark, section twenty-nine, township of Raisinville, where it forms a ledge of a foot in thickness. Some portions are beautifully white and are nearly pure silex. It breaks easily, and is inclined to disintegrate. It has not been used except as a scouring sand.

Near the west line of section nineteen, rock appears at the surface and has been quarried superficially. It is a siliceous limerock, of dark color, and when quarried, moist and soft, and may be dressed with ease to any required form. Owing to its want of compactness, it may be doubted whether it would be

permanent exposed to the action of the atmosphere. It has been employed as a building material at Monroe.

Opposite Lawrence's mill a smooth ledge of limerock forms the bed of the Raisin, and a quarry has been opened on the upland several rods south from the river. The latter furnishes a siliceous limestone, varying in color from a light to a dark mixed grey.

In a southwest direction from the above, in town of Ida, rock is found at the surface over a small area, on section four. A superficial stratum only has been quarried, of a foot thick, which is said to afford superior lime.

On section sixteen a siliceous limerock appears in the bank of a small pond and has been opened to depth of four feet. It removes readily in slabs three feet in length with thickness of four to six inches. Color light yellowish gray.

A vesicular limerock forms the bank at the head of Ottawa lake, town of Whiteford. It affords excellent lime.

A compact limerock also appears in an inlet at the foot of Ottawa lake and has been quarried for lime. Portions are siliceConsiderable calcareous spar is contained.

ous.

West of the range just described, limerock makes its appearance on the Macon river just above its mouth, and forms its bed for a mile. It has been quarried extensively, but the excavations have not penetrated below the first solid layer, a depth of eighteen inches. It is mostly of a dark gray color, sparry, approaching a chrystalline texture, and abounds with fossils. Portions give out a very strongly bituminous odor. The stratum exposed is very continuous and has been removed with wedges in pieces ten feet in length; but the blocks are apt to sever under the chisel. From this locality are said to have been furnished the caps and sills for the court-house at Monroe. It will compare in appearance with the much admired Ohio stone. This locality is said to afford the best lime in the county.

Rock of a similar character forms the bed of the Raisin at Dundee.

Lime.

More or less has been manufactured at most of the localities of limerock above mentioned.

Three kilns are maintained by the quarries at Plumb creek. Probably nine hundred or one thousand bushels are made annually.

At the quarry on section nineteen, Whiteford, five kilns have been burned, of five hundred bushels each.

At the Macon quarry eight kilns have been burned, of eight hundred or one thousand bushels each, which sells at Tecumseh for four shillings per bushel.

Sand.

The only locality, particularly worthy of mention, is that of the disintegrated siliceous rock found, as before noticed, in Raisinville, on the farm of Mr. Thomas Colwell. This bed was noticed by the State Geologist in his report of last year. It is mostly pure silex, and for the manufacture of glass, superior to any yet found in the state. A specimen of glass manufactured from it, in the possession of the proprietor, was unusually transparent and free from flaws.

Much of the sand of the plains in this vicinity, and even as far down as Monroe, is intermingled with white siliceous grains from this rock.

Clay.

The clays are in general too calcareous to be used with advantage for bricks or pottery. The upper brown or yellow clay is least so, and may be found conveniently for brick at numerous places throughout the county.

The manufacture has been conducted extensively at Frenchtown, opposite Monroe. But few were made the past season. During the season previous, so far as could be ascertained, about one million six hundred thousand were burned at the several kilns. The clay is impure from the lime contained.

A single kiln of bricks has been burned at Brest.

At Mr. White's yard, Newport, one hundred thousand bricks have been burned. The first two feet of the clay only is sufficiently free from calcareous matter to render it fit for the purpose.

Attempts were made at two places in the town of Dundee to manufacture bricks, but were abandoned from the cause alluded to. Good bricks are said, nevertheless, to have been made from the clay on Saline river, in the town of London. All the clays in this region, that were tested, gave very strong indications of lime, so much so as to deserve the appellation of marly. As the clays, even in proximate situations, often differ much in this respect, it is important to test them with a simple acid. Good vinegar will answer an ordinary purpose. Clay, may, no doubt, be found considerably pure; besides that expense and disappoint ment may often be spared by a previous knowledge of the cha racter of the material employed.

Marl.

A bed of shell marl (bog lime,) underlies the marshy tract bordering the lake, near the city of Monroe. It has been penetrated to the depth of a foot by ditches, for a considerable distance. The deposite has probably a thickness of several feet, and appa

rently underlies the whole continuous tract of marsh, an extent of about a square mile.

A tufaceous marl is also deposited in considerable quantities by springs in the vicinity.

In town of Exeter, section seven, a marl is said to have been ploughed up, dry, and crumbling on exposure.

A deposite of shell marl was observed in town of Ash, (town six south, range nine east,) section nine. It occurs in a marshy swale, overlayed by two feet of muck or peat. The bed is about a foot in thickness and occupies an area of an acre. Similar swales are numerous throughout this section as well as in other parts of the county, and the proximity of the limerock warrants the conclusion that beds of marl may be found deposited on low spots, charged with springs.

The economical use of these marls has been noticed under the report of Wayne county. Probably many of the clays may be found approaching so nearly to marl as to be of great value as a stimulant manure to sandy soils.

Sulpher Springs.

Two miles below Monroe, near the marshy border of the lake, several springs issue from an immense mound. They are strongly impregnated with sulphur, and form thin white deposites of that substance. This mound occupies an area of four to six acres, rising about ten feet above the general level. Its surface is wet and boggy. This mound is evidently a deposite from the water of the springs, which running through crevices in the great underlying rock formation, becomes highly charged with lime, and on approaching the surface deposites that substance either in a soft plastic mass or as a coating upon the moss and surrounding vegetation. Thus marl and tufa result. This process may be observed now going on. Large quantities of moss, still alive, are covered with a thin calcareous crust. A mile further

south are numerous smaller mounds of similar origin. One of these discharges a considerable stream from a spring occupying a large cavity, in the centre. Here a foot thickness of white marl is disclosed, overlayed by two feet of crumbling tufa. The spring boils up through a cauldron of calcareous and vegetable matter, into which a pole may be thrust many feet. This mound is circular, one hundred feet diameter, and six fect high. Most of the other mounds consist of a very indurated lime, or tufa.

The famous sulphur spring in the Bay settlement, emerges from a low mound of similar formation, situated in the edge of the large marsh bordering the bay. It occupies a circular basin of one hundred and fifty feet diameter by forty-five deep. A stream flows from it which at its head is ten feet wide and three

deep, and has a considerable current. The odor of sulphur may

be perceived at distance of half a mile, though the water is not of extraordinary strength. A bathing-house was in contemplation at this place, but the unusual rise of the lake caused an abandonment of the project.

Springs occur in great numbers on Sulphur creek, town of Lasalle. They occasion mounds of the same character as those near Monroe, and discharge considerable. streams. A few of these united, formerly supplied a mill.

In Raisinville, section nineteen, is a strongly impregnated spring, discharging water sufficient to form a brook.

Another, on section twenty-five, forms the head of Plumb creek.

A spring of moderate strength issues from the margin of the Raisin, half a mile below Dundee.

A strong spring of sulphur and iron is said to be found on Stony creek, town of Exeter, section twenty-one.

On Swan creek, town of Ash, are springs impregnated with sulphur and iron. One on section thirty-six ascends in a curb several feet above the level of the stream.

These springs all afford a copious supply, and are unaffected by a drought which renders dry the channels of neighboring streams. This fact, with that of their rise above the level of surrounding waters, and their strong impregnation with the minerals sulphur, lime and iron, proves that they have distant sources and that they proceed from great depths below the surface.

Streams and Springs.

This county is intersected by a number of considerable streams, following a parallel course to the lake; but small branches do not abound, as in a country of more broken surface. Most of the streams supply a hard water.

Water is obtained generally without difficulty from wells and springs affording a good supply, extremely hard. It is occasionally impregnated with sulphur and iron, owing to the proximity of the limerock.

Several wells in the towns of Ash, Lasalle and Ida, sunk twenty feet, to rock, opened veins which filled them suddenly, causing them to overflow.

Wells on the plains which do not descend to the clay are generally soft; so that by proper precautions water free from lime may be obtained in those situations.

Bog Ore.

Several deposites of this mineral occur in the neighborhood of Petersburg and Dundee. The ore is much mixed with siliceous matter, and none of it can be considered of the best quality.