MORTAR.

We have a few remarks, on making it. This is commonly a mixture of sand and slacked lime. When sand cannot be had, pulverised dry clay or brick-dust, will answer as well.

To the sand and slacked lime, if iron dust, or manganese be added, a cement may be made, which will harden under water. With such a cement, cisterns may be made, tan vats, and cellar walls, that will answer many useful purposes.

Compact lime, is often used, as a manure, and our shell lime, is the best for that purpose. Sometimes, the stone is only pulverised, sometimes it is burnt. Many of our marbles that are full of shells, are very beautifully variegated, with spots of different forms and colors. Sand and emery, putty and tin filings, with water, are employed in polishing this limestone. As yet, we have discovered but few beds, of this stone, which are used as marbles. Time and further research may discover to us, other marbles, at no distant day, in our limestone region. It is quite probable, that the best marbles lie deeper in the earth, than we have, as yet, sought for

them.

Southwest of Springfield, on the road to Dayton, is a limestone of peculiar appearance. Its structure and aspect resemble, those in western New York, where gypsum and limestone abound. That near Springfield deserves examination, by some one, acquainted with those minerals of western New York. It is quite possible, that the limestone near Springfield may answer a good purpose for backs of chimneys, and ought to be tried, by exposure to great heat, and, by then throwing it into water, while thus heated. That it is an excellent limestone, for producing mortar, we doubt not, and by mixing with it a proper proportion of sand, it may produce a cement that will harden under water.

ORGANIC REMAINS,

Found in the limestone formation, in the Miami country and above Columbus, on the Scioto river, in Renick's quarry. R. Buchanan furnished us with the names of them.

The organic remains found in Tennessee and Kentucky, and probably in Ohio, not mentioned above, viz:

Of Favosites, we have a great many along the Scioto

valley.

PRIMITIVE ROCKS.

These are discovered, as soon as we have ascended the second ridge, south of lake Erie, as we travel southwardly, They consist of granite, sienite, black mica, and indeed every variety of mica slate, gneiss, and all the primitive rocks of this continent. They occur in amorphous masses, abraded, and smoothed, by friction, and show conclusively, that they are out of place, and are unconnected with any other rocks in, or near, where they now lie. They are generally, at an elevation of about seven hundred feet, above the present surface of the ocean. But where the earth has been worn away by some stream of water, near them, they have, in some instances, been undermined, and have fallen down, on a lower level. These boulders, are found in large masses, covering in some places, several acres, reposing on the north sides of hills, of a diluvial deposite. They are rarely found on the southern ends of hills, unless removed thither, by some more recent revolution, than the one which deposited them originally in this country. These primitive rocks, we have seen all along the southern shores of the northern lakes, from the east end of lake Ontario, to the western side, of the southern end of lake Michigan. They are uniformly found at about the same height, unless removed by some force more recent, apparently, than that, which, originally deposited them in this region. From east to west, they extend, at least eight hundred miles, in a right line. Their elevation is everywhere, nearly the same, above the present surface of the ocean, and they are most numerous, on the northern ends of hills, pointing a little east of north-about three points of the compass.

When we say, that these rocks are found, thus, in a line extending from the lower end of lake Ontario, to the western side of the southern end of lake Michigan, we do not say, that these rocks are not found, east and west of these limits. But, thus far, we have seen them, and have carefully examined them, in person, and have noticed, carefully, every circum

stance attending them. We saw none of them, west of lake Michigan, between that lake, and the Upper Mississippi.

They are found, in some instances covering half an acre of surface and sometimes, three acres. There is such a deposite, resting on the northeastern end of a diluvial hill, just south of the road leading from Dayton to Cincinnati, about three miles, perhaps less than three miles, southerly of Dayton. There is such a deposite, in the northwestern corner of the town plat of Circleville, partly covered with earth, by some later event than the one which brought these rocks here. There was, when this town was first settled, such a deposite, on the north side of the great mound, in this town. These rocks are found in considerable numbers in Madison county, resting on the surface of that elevated, diluvial plain.

Considerable numbers, may now be seen, resting on the bed of the Olentangy creek, several miles below the town of Delaware between that town and Worthington. They have been undermined by the washing away, of the clay slate under them.

These rocks, have been often used, for millstones and sometimes, one boulder, is so large, as to make several mill stones. These are granitic rocks. They are used too, for underpinnings of houses and barns. The court-house in Madison county, stands on these old rocks.

By what means, were these rocks, transported here, and left, on our surface? That they have been brought here, long since the revolution, which deposited our sandstone and slaty rocks, of secondary formation; seems evident, from the fact, that they rest on the surface of a diluvial deposite of rolled pebbles. This diluvial deposite of pebbles, &c. is more recent than the sandstone and slate rocks. It seems evident, too, that the force which transported our primitive rocks here, was not so great as the one which transported the rounded pebbles, otherwise, the large boulders would have been whirled around the hills, and left at the southern ends of them.

Northern navigators, often tell us, of iceberges, floating in polar seas, with rocks, imbedded in them. We see the same

thing take place, on a small scale, in all northern countries, where the ice adheres to the beds of the rivers, on the return of the spring, when the current breaks up the ice. At its bottom, pebbles adhering to the ice, are borne downwards, by the current, and transported, until the ice is dissolved by the warmth of the sun. So, in polar regions, powerful winds and waves, break up the ices, the rocks at their lower surface adhere to the iceberges, and are borne away, to climes far distant from their native beds. What adds to the evidence, in favor of such a transportation of our primitive rocks, is the fact, that their lower surfaces, show evident marks of having been scratched, raked and injured, by coming in contact with obstacles, on their journey hither. The upper surfaces and sides, have not on them, marks of equal violence. The last revolution or catastrophe of our globe, brought these rocks here, and they moved slowly over the surface of the ocean, then elevated only seven or eight hundred feet, above its present level.

If the same catastrophe, at its commencement deposited the round pebbles, in oblong, narrow hills, their ends pointing a little east of north; our primitive rocks, though brought here by the same current of water, yet it had, by that time, lost nearly all its force, and had settled its surface, five hundred feet, at least, at that time, and, soon afterwards, subsided altogether, and left our present lakes and rivers, to accomplish what they have done since. Lake Erie has settled its surface one hundred and seventy feet, since that period, and many of our rivers have also lowered their beds, in the same time. These rocks, are FRAGMENTS OF HISTORY, not to be overlooked, by the historian. They speak a language not to be misunderstood. The masses of rocks, in the hills of our sandstone region, show on their northern ends, and sides, marks of violence; they are scratched, raked and injured by violence. We have examined these points of rocks, on the northeastern ends and sides of hills, in Scioto, Lawrence, Jackson, Fairfield, Hocking and Meigs counties, and we always found the same evidences, of violence done to their northern extremities.