REPORT ON THE GEOLOGICAL SURVEY. [Submitted with the Governor's Mtessage.] To His Excellency, Lucius FAIrCtHILD, Governor of the State of lWlisconsin:SIR: The instructions accomparfing miy appointment as Commissirner of the Survey of the Lead District, namely, that nothing need be done, that has been satisfactorily done already, and tLht the time and money spent in this Survey should be to collect that Clarss of information that would be of the greatest practical benefit to the mining region, has been strictly adhere:' to in my work, Your subsequent letter, however, containing the wishes of certain influential, men in the lead district, namely, that the work provided for in the bill, be prefaced by a careful, and critical survey of the mineral veins of the lead district, in their rzlation to the lower strata, with a report of the same, as early as possible, defined clearly the work to be done first. Although I saw at the time the impootance of this, I did not realize it fully until I had entered orn the work. The mines of the lead district, up to the present time, have been confined mostly to that portion of the strata above the water, where mining operations can be car ried on at a trifling expxnse. But this portion of the strata is almost exhausted; most of the important mines are worked down to the water, and as they are finished to this point in depth, they are abandoned. Tis i all the present system of mining (individual interprise) can do, all itc conte.mplates doing. To work these mines deeper, or to follow these fissures into strata belvw twose into which they have been already worked, a new system of mining must be introduced; a system that combines capital, and skill; a system like that by whLeh mines -(re worked in other parts of the world. There isno mineral strata, or system of mineral veins any where, that 2 could be profitably worked many years with such a system of mining as that by which mining operations have been carried on in the leIa district of Wisconsin. But before such a system can be successfully introduced, and established, the question of the origin, and nature of our mineral veins, with their relation to the lower strata, must be settled, so far as the present condition of our mines can do it. Befori any man, or company of men,, will be disposed to risk the amount of money necessary to unwater those mines at a greater depth, either by levels, or pumping, they will want to know if the theory advocated in our last Report is really founded on facts; if not, they will want,to know what relation these mineral veins bear to mineral veins of other mining regions; whether or not they are connected with physical forces actirg from beneath, and what the probabilities are of deposits of ore in the lower strata. Besides this, the question of proving the lower strata of the lead district by sinkiing a deep shaft into it, has been before the Legislature more than once. And should the State see fit at some future day, to appropriate a sum of money for this purpose, nothing would be of more importance to the experiment, than a knowl-,edge of the origin of our ore deposits, and their relation to the lower strata, as far as the phenomena of the lead district will afford it. Without this knowledge, a selection of the proper place cannot be made; and without a proper selection, the chances area hundred to one that the money will be spent to no purpose. The general and pressing wants, then, of the lead district, seem to center here; and to meet these wants, as far as a survey of this kind can meet them, h:as been my object. It must not be expected then, that my report will-be a report of the lead district as a whole, but only of that class of information that has a bearing on this question. In presenting it, I shall, as far as possible, confire myself to the following order: i. A description and classification of the phenomena of the lead district, (that is the observed features of the lead district as such,) and their relation to the phenomena of other mining regions. 2. The nature of the underlying strata, and their adaptation to mineral veins. 3. Mineral veins in general, but those of the leadc district in particular 4. Scientific, practicai and theoretical considerations. But first of all, allow me to say that in order to get a clear and correct idea of the underlying rocks, and the relation of the mineral veins to those rocks, a vertical section, as far as it was possible to get ore, was Lncessary, To obtain this there was no other way, than b, examining the different layers of rock as they were brought to the surface by the gradual rise of the strata to the north of the lead district. In traveling from the state line south, to the north, one hundred miles alcnL the fourth principal meridian, I have found a chance to examine the different beds comprising the lower strata of the lead district, and have laid them down in a map that will accompany this report. My object in collecting and carefully describing the phenomena of the lead district, is to present ia as clear a light as possible the physical conditions, and the evidences'of that class of physical conditions of which our mineral veins, and our deposits are the results or fruits Unless we ignore altogether the teachings of nature, we must admit as true, that mineral veins and ore deposits in the mineral kingdom are as much the results or fruits of well defined and unchangeable laws, and physical conditions, as are the fruits and flowers in the vegetable kingdom, cr animals inr the animal kir gdom. But writing as a practical man, for practical men, it may be well perhaps, to explain what I understand, and what I would have others understand by physical conditions, for in order to get a clear idea of the phenomena of mineral veins, and the characteristic features of mineral strata, nothing is of more importance than correct knowledge, either practical, or scientific, of the physical conditions, and forces with which productive mineral veins always stand connected. To do th.s, I will avail myself of the anology that exists between the physical conditions K f the mineral kingdom, and the physical conditions of the vegetable kingdom, for we are more familiar with the latter than with the former, anc the illustrations which it furnishes will explain far better than any language that I can command. In presen'iag the physical conditions of the vegetable kingdom, I shall present them not as the deductions of reason, but as active agencies now at work, producing before our eyes, their results in vegetable forms of matter. In this process of vegetable production, we notice certain physical conditions that are essential. 1, There is a certain condition of the soil, that is adapted to the nature of the plant. What this condition of the soil is we know by observation, and experience. 2 Heat, or a certain condition, or range of temperature. What this condition, or range of temperature is, we have found out also by experience, and we look for vegetable productions accordingly. 3. Water in a humid condition of the atmosphere or in the form of rain, or applied by irrigation. Other minor conditions there may be, but these are essential. Along lines where these combine in certain proportions, we find productive zones of vegetation; where they do not, we find barren wastes. Thus the relation of vegetable products, to well defined, and unchangeable thbysical conditions, is so0 plain, and simple that nobody doubts it. In mineral strata, and mineral veins, we find evidences of the same elemesnts entering into, and governing the physical conditions of the mineral kingdom. The experience of mining has delnonstrated beyond doubt, the fact, that the deposition of ore in the fissure, depends as much on certain conditions of the rock, as the vegetation of a plant does on a certain condition of the soil. The miner looks just as much to these conditions of the rock for the metals and their ores, as the farmer does to the condition of the soil for his plants. And we hear the miner talk just as much a}out minqral bearing rock, as we do the farmer, about productive and barren soil. In the formation, and filling of mineral veins we recognize, (andO that very distinctly to,) heat as one of the most efficient ar-encies. Now carl we possibly exolain the phonomona of mineral veins, with their deposits of ore without reference to water as the medium in which this material has been prepared, and through which it has been brought into the fissures, and held subject to the chemical conditions that has wrought it into its present crystaline form. Along those lines in the earth's crust, where such conditions are known to have existed, and where evidences of their past activities still remain (although like fossils in the rock), are the lines along which our mines and productive mineral veins are found, and they are found only along such lines. They are, indeed, as much the isothermal lines of the past, that mark the distribution of temperature, and conditions necessary to the production of mineral veins, as are the isothermal lines of the present, that mark the disiribution of temperature, and conditions necessary to vegetable production. In our examinations, then, of mineral trata, or explorations of the country for mineral regions, no surer guide can be furnished us than the evidences of the aeticn of these physical forces and conditions. The disturbed and peculiar conditions of the strata along lines where these evidences are found, furnish most. if not all, the material of our knowledge, from which all practical as well as scientilc deductions are made. Hence. the importance of presenting in ny report, in as clear a light as possible, the phenomena of the lead district, that the physical conditio. s of which they are the results, may b: apparent, and that deductions, both scientific aod practical, may be made understandingly. But before I enter fully on the description of the phenomena of the lead district, allow me to trace a little further the analogy between these two departments of nature. It will enlarge our views, and clear our conceptions of natural phenomena, and enable us to recognize more distinctly the laws that underlie them as their cause. We know that the vegetable and mineral kingdoms meet in the crust of the earth; the material of which vegetables and minerals are composed, are in many respects the same; both arethe results of physical conditions; and in these conditions we find the same, or similar elements. Yet there is a line of distinction sharply drawn between these kingdoms, their laws and their products, over which the one can never pass to the other. In the economy of nature, as presented in the vegetable kingdoum, we find heatand water, with other elements worked up into varied forms, and blended in given proportions, and circumscribed by natural law-thus constituting the physical conditions necessary to vegetable productions. Where these conditions prevail, vegetabl;, productions abound; where they do not, barrenness is the result. Hence the isothermal lines bounding the zones of mean annual temperature, and pointing out in the vegetable kingdom, the comparatively barren and productive places. But these physical coniditions, ia their adaptation to tihe vegetable kingdom, are atmospheric, and act upon it from above; the heat is evidently solar, and can be traced without doubt to the sun as its source. Among the varied and complicated laws governing the mineral kingdom, we notice heat and water playing a very important part. In the conditions necessary to the formation and filling of mineral veins they seem to be essential. The mechanical disturbances of the crust of the earth that produced the fissures in which our mil.eral veins are found, are evidently due to some form of heat. The metamorphic rocks, in the region of which our most productive mineral strata are found, have been changed from their original condition by heat. T'he modifications of other rocks not classed with the metemorphlc, but more intimately connected with mineral veins, afford strong evidences of the unequal distribution of heat.; The ores of every kind, filling our mineral veins, and other cavities in the rock, have evidently been formed by the rigid laws of primeval chemistry, the fires of wShose laboratories have been ted by natural heat. Thermal waters and boiling springs, (the lingering remnant of what was once a mighty host of physical force), remain to tell us that they had their origin in, and received their solvent powers from heat. The systematic grouping of fissures in mineral strata, under the direction of magnetic or electro-magnetic action, is due, doubtless, to varryirg degrees of temperature, or the unequal distribution of heat. Indeed, it is difficult to find anything it, the mineral kingdom connected with mineral veins, that is not due either directly or indirectly to heat. Here too, as in the vegetable kingdom, we find certain conditions blending in certain proportions, and certain forces uniting as it were in one to produce certain results. And it is only when such, and where such conditions prevail, that such results are obtained. The lines that mark the course alid action of these forces, are legible in the crust of the earth, as the lines that mark the zones of productive vegetation on the surface. If we examine closely the physical conditions and forces of these two departments of nature, but few things will strike us with more force than the laws governing the absorption and radiation of heat. In the vegetable kingdom every tree, every plant, every flower, in fact every organism, seems to possess different absorbing, and radiating powers, by which it is adapted to receive the warming, life giving rays of the sun; indeed it presents one of the most refined systems of order, and adaptation. And yet this beautiful system is made to depend upon the amount of heat received from the sun, and upon the circemstances of the position of the earth in reference to the sun. No less distinct are the evidences of the relations of hea', and the laws governing its abs rption, and radiation, to the varied forms of crystalline matter in thie mineral kingdom. But between the phenomena of heat in the vegetable kingdom, and the phenomena of heat in the mineral kingdom. there is a marked, indeed, an essential difference. This difference arises, no doubt, not from nM eEsential differerce in the physical characters of heat, but from an essential differe-ce in the sources from whence it flows. WVe cannot fully comprehend the difference between' minerals and vegetables, both of wbhch are the products of nature, formed out of similar material, by heat as one of the elements of their conditions, until we regard the line that separates-the vegetable and mineral kingdoms, to be the line that separates between the products of solar and terrestrial heat. The evidences of this fact are strong and convincing, they appeal to our senses, and through them carry conviction to the mind. The uneducated farmer, feels while moving amid the rich unfoldings of vegetable nature that the heat to which these organi ms are subjected as their life giving power, flows from the sun as its source: while tl;e miner, untutored as he may be, in his downward, course in the mine. feels that the increasing temperature he encounters, is produced by heat arising from some internal source. The convictions fastened on my mnid in early life, wh le coming in contact with these influences and evidences every day in the deep mines of Cornwall, England, can never be changed by arguments to the contrary. It may nlot be so easy to convince others who have not been exposed to such influci ces, or who have not been mad. acquainted with such evidences It is natural for us ~without such evidences, to believe that the earth blneath our feet is a solid mass of rock. But even then one would suppose that the first shock of an earthquake, or the first sight of a volcano in the act of pouring forth its molten lava, would unsettle our faith in this, and prepare the mind for the reception of any evidenoe that would throw light on their origin. The rapid advances of the natural sciences, however, and the careful experiments on the increasing temperature downwards of our- deep mir.;s, are fast divesting this question of central heat, of its hbypothetiaiL, and e -en of its theoretical character, and clothing it with the more substantial garments of sober truth. The obervations of Prof. Palmieri, made during the last eruption of Vesuvius, has brought to light the following startling facts, namely, that he noticed on that occasion, distinct tidal phenomena, indicating t[-at the moon's attraction occasioned tides in the central zone of molten lava, in quite a similar manner as it causes them in the ocean. This would leave us to infer that volcanic phenomen a are connected at a certain depth beneath the surface, with a continuous sea of molten lava, or rock. Prof. David Forbes, in one of his recent lectures, sums up the evidences of deep mining on central heat, in the followinglanguage: " A numerous set of experiments made ia deep mines in various parts of the world, often far distant from one another, has most conclusively proved that the temperature of the earth, at least as deep down from the surface as has been explored by man, increases in direct ratio as we descend towards its center. Other observations on the temperature of the water from deep-seated and hot springs, and from artesian wells, fully confirm the E.xperiments made in mines, and show that the temperature of the water furni hed by them also becomes higher in proportion to the depth of the source from which it is derrived. "' As might naturally be expected, the interference of local causes renders it a matter of considerable diffiiulty to determine the true mean general rate of such increase in temperature of the earth's substance downwards; still, in the main, observers all agree in placing it at somewhere between 1 1-2 O and 2 1-2 0 F. for every hundred feet in depth, so that we cannot be far wrong, if for our purpose we estimate it at 2 o F. for every hundred feet in depth, or a rate which amounts to 121 ~ for each geographical mile nearer the earth's center. Since no facts are at the present time knowrn which can in any way invalidate the supposition that this, or a somewhuat similar rate of increase in temperature holds good in still greater depths, it is perfectly corre.t and justifiable reasoning to assume that, such is actually the case, and therefore a single calculation will show that at a depth of about twenty-five geographical miles from the surface downwards, a temperature of about 3,000 0 F. should be attai ed, which would represent a heat at which iron melts, or one sufficient to ke p lava in a state of perfect molten liquidity at the surface of the earth." The distance of twenty-five miles between the source and phenomena of internal heat, strikes us at first as being too great to be admitted as true. But this distance sinks into nothing when we reflect on the fact that twerty six millions of miles separate the sun from the phenomena of the vegetable kingdom, known to be the results of its beat. And then we have reason to believe that it's the passage of heat through this intervening strata, that works it up into the manifold agencies that produce the simple and complex phenomena we observe in the crust of the earth; such as earthquake action, volcanic action, metamorphic action, thermal waters, boiling springs, and the complicated phenomena of mineral strata, arid mineral veins. At all events there is nothing to prove to the contrary, but that these phenomena are the results of heat arising from the same source, and that source the molten condition and elevated temperature of tLe earth's center. If by the aid of science, Sir John Herseqlel could say, 3S years ago, that " The sun's rays are the ultimate source of almost every motion wh'ch takes place on the surface of the earth," we may safely say to-day, that the radiation of nebular condensation, (that is the passage of heat from the cooling interior of the earth to the surface,) is the ultimate source of almost every motion which takes place, and has taken place in the crust of the earth; it is to the mineral kingdom what the sun is to the vegetable kingdom, the ultimate source of physical forces and conditions. This brief explanation of the nature of the physical conditions and forces of the mineral kingdom, will prepare us to understand them, and give us clearer conceptions of the phenomena of the lead district, as presented in my report. PHENOMENA OF THE LEAD DISTRICT. The history or mining in all parts of the world, and the experience of all who have had much to do with this branch of industry, testifies, without exception, to the fact that mineral veins, or ore districts, are always associated with lines of physical disturbance in the earth's crust. They may be mountain ranges, or more gentle elevations. They may be dykes of igneous rocks, or lines of fracture in the earth's crust; but always lines cf physical disturbance of less or greater intensity. But of the lead district of Wisconsin it has been said, that, it is an exception to this general rule, and the relation of its fissures and ore deposits to physical forces acting from below, has been denied, and other conditions called in to explain their phenomena. Although one may not endorse the theory fully, yet when it comes from high authority it is difficult not to be influenced bv it in cur investigations, to a certain extent, at least, But in entering upon the investigation of the phenomena of the lead district, I resolved to rid myself of all theories, and follow only the light of facts, so far as I understood them. I think it was Prof. Tyndall who said:' There is no discovery so limited as not to illuminate something beyond itself." Every investigator of nature knows how true this is; and furthermore, he knows that there is not a fact in nature but what possesses this illuminating power to bring within view another,fact which lies beyond it; a fact we could not see but for the light reflected by the one in our possession. It is this that gives that charm and enchantment to original investigation, that comes not within the sphere of those who merely read science in books. Free from theoretical bonds, and with a few facts to begin with, I entered unon the investigation of the phenomena of the lead district; commencing with the simple fact (with which all are familiar) that our ore deposits are invariably Connected with fissures. 9 Standing for a moment on this fact, and looking around the circle which it illuminates, I see another fact. This fissure is only Cne of a grcup of parallel fissures of from five to ten feet apart, called by the miners a range. And within this illuminated circle there is still another fact, that is, there is an indisputable relation between this group of assures and the ore deposit. In the combined light of these facts, our range of vision is con. asierably enlarged. We see now that this single group of fissures, (,or range) is only one of a group of ranges extending every way, and forming wbhat is called a mining district. In the centre of this district the ranges are near each other, and rich, but as we extend away from the centre the ranges become scarc'r and not so rich. But now away on the horizon of our vision, another fact appears, and in its light we can see that this group of ranges, or mining district, is bounded on the east, west, north, and south by barren ground. By the concentration o the light of these facts, the range of our vision is wideniug, and we see now coming into view beyond this barren ground, other, and apparently similar mining districts, as though they were arranged in an east and west line. If this is a fact, it is an important one, and a new discovery. But before we accept it as afact let us submit it to a rigid test. To do this let us go to the southwest corner of the State, where these tminning districts commence, and drive down a stake at Fair. play, and another 4 or 5 miles to the north, at Jamestown. And now let us draw two lines from thes- stakes east, or a little to the north of east to range seven, in Green county. Now let us carefully lonx along within those lines, and see what we can find. We have (within those lines) the mines of Fairplay, Jamestown, iHazel Green, Benton, Newdiggings, and Shullsburg. Extending east from Shullsburg, no very important lep: sit of ore is found until we reach the east side of the west Peccatonica, where we find Wyota, on the extreme north line, and the region about Monroe the eastern extension of these mining districts. While working out the details of this system for grouping, along this range of country through nine ranges of townships, I was never more surprised in the results of a survey than to find (when figuring up my notes and bearings, which had been taken by myself with great care) that within a width of six miles, we have a belt of mining districts, ulong abelt of mineral land, extending in nearly an east and west direction for at least fifty miles. As I stood one beautiful day on the high grounds above the village of Newdiggings with my compass set to within a few degrees of east and west, and looked over this long range of mining districts, I felt confident that in all m) experience in mining, and mineral labors, I had not Eeen, to such an extent, a better defined belt of mineral land. Nor do I believe that another belt of equal extent, and depth, either in this, or any other country, has yielded more ore than this, or paid better for the capital invested. 10 It is, however, one of the unfortunate mistakes of our State that no mining record has been kept, no clue even left as to the quantity of lead ore thus far obtained. We may form some idea of the amount, however, by putting together sozme scattered facts recorded concerning some portion of those districts. Hazel Green furnishes the most reliable; and our thanks are due to the late Mr. Crawford for these. Prof. Whitney (who by the way was very careful not to overestimate our mineral resources) reported as reliable 127,000,000 pounds up to 1860, with an annual yield of about two million. We may, perhaps, safely set down for this mining district up to the present time 150,000,000 pounds And this amount of ore has been taken from a mining district not over four miles in length; and from fissures, and openings mostly above the water level, at an average depth of not over 45 or 50 feet. And this is only one of six or seven such like disticets along this belt. And then the mines along this entire belt are worked in the Galena limestone, mostly in the upper portion of this form.ation, with the blue limestone underlying it all the way. And shall we now abandon our mineral resources here (as we are more than likely to do, unless soine special effort be made to revive our drocping mining interests), and leave these half-developed mines to future generations? Will they not be apt to give us a place in the scale of civilization not much in advance of that race from whose hands we but a few years ago received these lands with the mines partially opened. In putting together those little facts, such as fissures, and groups of fissures; ranges, and groups of ranges; distri ts, and groups of districts, all of' which are related, we have this well-defined mineral belt as afact. And inasmuch as this fact is the sum of all those little facts put together-so, also, the light which it reflects is equal to the s,tm of all the light reflected by those little facts; hence, standing upon this fact, we are prepared now to examine a higher class of facts to which this belongs. Looking north, we observe in the distance other mining districts apparently arranged along a similar line On reaching town 3, and following its south line west to where it i tersccts the Mississippi, we no'ice very similir phenomena to that described in the belt just referred to. Let us put~ down a stake here, also, and measure four or five miles north, and put down another, and from these two stakes draw two lines as before, east, or a little to the north of east, and see what we include. We have the mines of Potssi, British Hollow, Rockville, Pin Hook, Red Dog, Whig, and Platteville, in Grant county. In extending into La Fayette county, this mineral range encounters the elevated lands of the Platte Mounds, and but little is seen of it until we reach Calamine, Fayette and Argyle, where it mey be seen as a mineral belt extending into Green county, where, like the other, it;s lost in range seven. What was said of the other belt may be said to a great extent, of this; only not quite as productive, perhaps, as a wholn. With the additional light of this fact, it is not difficult now to see another belt near the south line of town 5. A belt, though well defined through three ranges of townships in Iowa ceCnty; and one in Grant, (including the mines of Mineral Point, Diamond Grove, Lost Grove, and Mifflin, in Iowa county, and New California, and Crow Branch, in Grant county,) is nevertheless disturbed at the west end, as it comes in contact with the geological break along the valley cf Grant river, where it seems to be borne down a little out of its course to Beetown, but there it again takes its regular cbase. Towards the east end it encounters a very heavy ridge, or elevation of land coming down from the northwest of odgoeville, and extending in a southeast direction through the county. This belt, when coming in contact with this ridge, or elevation of land, seems to fcllow its course, and groups of mineral ranges are found along its flanks for ten or fifteen miles. The geological features of this belt are s-rmewhat different to what we find in the other two. The strata is more broken; evidences of dist'urbance of the lower beds of the strata are seen in the undula tions of the sandstone, and the protrusion of the lower magnesian limestone in several places through the sandstone. Owing to this there has been greater denudation, consequently we have here, in many places, a large exposure of the blue limestone, affording a good chance to study the mineral bearing character of this form ition along a line of physical disturbance. The mines of Mineral Point Diamond Grove, Lost Grove, Mifflin, and Crow Branch, are now and have been for several years past, confined mostly to this formas tion.; establishing beyond doubt its mineral bearing character. To this I shall refer again. North from the third belt we commence to ascend a gentle elevation, which culminates in about the middle of town 6. Along the south flank, or near the centre, is another well defined belt, extend ing through a large portion of Grant county, the whole of Iowa, and for several miles into Dane; and the mines of Fennimore, Wingville, Spring Valley, Dodgeville, Ridgeway, Porters Grove, and Blue Mounds form a chain of mineral ranges, extending through nine ranges of townships; and their course is as distinctly marked as the lines of the town (6) in which they are found, The north side of this belt is said to be the extreme north side of the lead disg trict, beyond which no ore has been found, and beyond which it has been said, none will be found, We will pause here for a moment and gather up what facts we have discovered The phenomiern presented in these belts of mineral land, cannot fail to lead us to regard them as separate, and.distinct mineral belts. There may be places where strong north, and south fissures carry the ore deposits out a little farther in one place than awu tier; or w here small deposits may be found along those north and south fissures between those belts. But such are exceptions and met with but seldom. The fact, however, of their persistenet course, their parallelism, their eastern, and western extension, establishes beyond doubt the facS, that they are separate, and distinct, although closely related mineral belts. In the report of 1862, the grouping of the fissures into ranges, and of the ranges into districts was noticed but no effort was made to arrange it with a higher class of" phenomena, or to show the relation of. these facts to a higher class of facts, consequently the lead district has been looked upon up to this time as a heterogeneous unsytemized a~ggregation of mineral ranges, But the above facts show, that there is a systematic arrangement. of the phenomena'of the lead district under some natural law by which it forms itself iato a perfect whole. Hence we have a.roup of fissures forming themselves into a range; and a group of ranges forming themselves into belts, and thus we fiad the lead district composed of four well defined belts of mineral land, running parallel to each other, with about the same eastern, and western extunsion. Now the question for consideration is, do these important. and well defined relations end here, or is there a physical basis which they tend, and to which they belong If in the light of these lesser facts with which we commenced we have found our way to those larger facts by which we have thus far reduced the phenomena of the lead district to a system, let us try in the light of the larger facts if we can find any evidence of such a basis, In astronomy, the slightest disturbance of a planet in any given point ef its orbit is sufficient to turn all astronomical appliances to that point in the heavens to look for the cause. In geology the slightest dtsturbance of the strata along any given line ought to be sufficient to turn all geological observations to that spot for the same purpose. I noticed in the hasty description given of the third belt of mineral land, slight disturbances of the strata, such as here and there protrusions of the lower -magnesian limestone through the sands.one. This to an unbiased geologist would be sufficient evidence of the action of physical forces from below along the line of this belt, but to a man who will dispute every inch science gives,it will weigh but little. I will therefore use it only as a guide to more important phenomona. The Suth and last belt is, as before stated, along the south flank of a well defined elevation of land running parallel with the belt, with alout the same eastern and western extension. I will not stop to describe this elevation. or to show its relation to forces acting from below. The following quotation from the report of 1862 will be sufficient for this purpose. "The line of water-shed, as represented o:. the above diagram,be 13 tween the streams flowing north, and those running to the south, is almost exactly a straight east and west line from the Blue Mounds to Prairie d- Chien, and for a distance of almost sixty miles. * * No one observing the position of this line could fail to recognize the fact that its origin was due to some general geological course, as will be explained farther on' page 103 On page 387 we have the following reference to the sae elevation. " As a proof, or, at least, a strong indication that the asis of elevation was an east and west one, the fact may be here again alluded.o which was stated in a preceding chapter in regard to the water shed of the district being an exact east and west line, through the whole extent of the lead region." Now the fact that the fourth belt is along a well defined elevation of land, of the same bearing and extension, produced by the same general geological cause, acting from below as an elevatory force, proves beyond all doubt that the slight disturbances referred to in the next belt south, must be the result of the same, or a simi. iar cause. And what can be a more logical inference than that the otherbelts have the same origin, and that the phenomena of the whole district are the results of the same general geological, cause. Here we have a new fact, and a very important one, namely, a mechanical force acting beneath the strata of the lead district, and giving character to its phenomena. This fact, sheds new light on our investigations, and enables us to take higher, and more intelligent grounds, from which we can see a c ntinuation of parallel elevations such as the Baraboo Hills and other ridges, and foldings of the strata extending away into the far north. These facts indicate strongly another fact, namely, the presen. e of a north and south axis of elevation, to which these east and west elevations, and belts of mineral land belong as subordinate features, crossing it, at right angles, limited to it in its eastern and western extension. If this le a fact, we shall doubtless find here, not only the physical basis that underlie the phenomena of the lead district as its cause, but a line of physical disturbance along which other and perhaps more important ore districts may be found. But before we accept it as a fact. let us submit it also to a rigid test. In order to put this in a tangable form so as to examine the facts to the best advantage, let us take the length of those belts, as the width o' tee lead district, and from each end draw a line north, Within those lines we shall find the following fwczts, which, of'themselves are s ufficient to prove the existence of the north and south axis above refe-:red to. (1.) if we take a narrow strip of land near the centre of the belt wi;hin those lines, say three ranges on the east, and one on the west of the fourth principal meridian, four ranges in all, we shall find in this little narrow strip more mines, and from these mines more ore has been raised than from all the lead districts outside of it, (notwithstanding it includes in width fourteen or fifteen ranges 14 or townships,) I may say twice the amount, ani should be within the bounds of truth if I were to say three times the amount. Within those four ranges of townships the ore deposits are near each other. and often very extensive, but as we extend east or west from them they become few and far between, and often, though not always, small. In connection with this I will notice the fact that within this narrow Strip of land all of our zinc deposits are faund. Indeed, we may strike off the range to the west, andi narrow the strip to three ranges and we shall include all the zinc deposits of any amount. This may be accounted for from the fact that along this line, north and south the blue limestone is brought up a great many feet above where it is on either side of it. (2.) Beth to the east and west of those lines, we find heavy deposits of drift, and following close on those Inue, both to the north and the south; while within those lines no portion of this formation is found in the lead district, or as far north of it as I have examined, This fact alone is sufficient to prove that this lit. tie strip of land, along which the mines and mineral veins of Southern Wisconsin are found, and that continue to extend north beyond them, was a well defined elevation at the time of the drift formation. It must have stood then as an island surrounded with the waters of that period, as it stands now an island in the midst of boulders and gravel. (3.) Aad the most important fact is, this driftless strip of land within those lines, is an anticlinal, or crest line, from which the strata dips to the east and to the west. To prove this, it has tak. en a vast amount of time, and close observation, as you will see by the.vast tract of country I have'examined. The importance of this fact to the lead district, and to the mineral resources of the State. is such that I will present here scme of the details of my observations; for if this fact is well established, the fact of a north and south axis must follow; and with this comes the fact of the relation of our mineral veins to the same physical forces acting from below; and then the fact also, that this north and south axis extending through the state will be the physical basis of our mineral wealth, and along this line other and perhaps more important ore districts may be found. The features of this anticlinal or crest line we must not expect to be very distinct Gn the surface. The disintegrating a:;d abrading agencies which, through vast cycles of the past, have been leveling down, and leveling up the surface of the lead district, have almost obliterated them; and to find them unimpaired, we must examine the lower and undisturbed beds of the strata. To do this let us take our stand at a point on the Mississippi, where we have a good. exposure of the lower rocks; we will commence at a point just west of Potosi. At this point we find the blue limestone down even to the water level. If from this point we follow a line east, or parallel with the mineral belts before referred to, we shall find the lower beds of the strata gradually rising as wA approach the center of the district. A little to the east of Potob, for instance, on a branch of the Platte river, we find the sandstone rising from the bed of the stream, and forming a ledge of rock along its banks, bringing up the blue limestone, at least fifty feet above its level at our starting point on the Mississippi. In ft, llowing this line across the Platte we find the lower beds of the strata still rSeing Not only do we find the sandstone, but the lower magnesian limestone that underlies it, forming ledges from fifty to seventy-five feet high, bringing up the sandstone, and blue limestone, not less than two hundred feet above its level, west on the Mississippi. Farthe- east on this line the lower beds of rock are not sufficiently exposed to enable us to determine just where the summit of this anticlinal is reached, or just where it commences to dip on the other side. If, however, we take our stand on the Mississippi, a little further north, about where the Wisconsin river enters it, and follow along the line of the Milwaukee and St. Pail Railroad, weo shall find a section across tLis elevation that will bring out to a great extent its outlines. At this point the lower magnesian limestone extends down to the water level, or below it, the Potsdam sandstone forming the bed of the river. In extending our examinations, east from this point, we find in a very short distance the sandstone emerging from beneath the valleys, and gradually rising until it reaches a point about the fourth principal meridian. Here we find an elevation of the Potsdarn sandstone from 200 to 250 feet above the valley of the Wisconsin river, and not much less than 300 feet above its level at.the Mississippi. After following it along for severnl miles, about the same level, a very perceptible dip sets in to the east, and it soon disappears beneath the deepest valleys. This section not only brings but the- fact that we are crossing an elevation, or a north and south anticlinal axis, but shows us just where the summit. is. To settle, however, a question involving general principles by local observations, was not safe, and to place it beyond doubt, a knowledge of the geological position of the rocks farther to the north, across this strip of land, was essential. The center of this strip, from the state line soath, to the middle of WoGd county, I explored several years ago, at my own expense, when I first brought to light the fact of a bed of kaolin at Grand Rapids, and also others not far from Stevens Point, that are found along the flanks of granite ridges. For information on this part I can draw on my old notes. And by yo-yr kind permission I visited the east side of our state last spring, as far north as the upper peninsula of Michigan; and this fall the western side as far north as lake Superior, and am now prepared to state the facts obtained in those hasty visits. On the east side of the line, running north from the lead district, and close to it, I find heavy deposits of drift, extending from Illi 16 nois on the south, to the upper peninsula of Michigan on the north. The strata does not rise so fast to the north along the eastern side of the state, as it does through the center, for we find the blue limestone as far north as Green Bay. On the west side of the State, that is tb the west of the Missis. sippi I inid the same drift phenomena close to the river, and extending north the entire length of th- State. On the west side of the State, as wellas on the east the wise or the strata towards the north is little or nothing compared to the rise of the strata. along the center. But let us put these facts and figures together and see what the result will be; or rather before we do this let us get a clear idea of the strata and its geological order. Tasking the azoic formation as a basis, we invariably find in this strata, the potsdamn sandstone, a layer of rock about 450, or 500 feet thick resting on it; the lower magnesian limestone about 3)0 feet thick resting on the potsdam; tbe St. Peters' sandstone, about 80 or 100 ieet thick, resting on the lower magnesian; and the blue limestone resting oa the St. Peter's. This is the geological order, and the thickness of these strata when every led is in its place, is from 800 to 900 feet. Now let us see what our facts will prove. We have the blue limestone on the east side of the State, as far north as Green Bay; on the west side as far as St. Paul, while within our lines (or the width of the lead district) it extends no farther than town seven in Iowa county. Thus we see that the blue limestone extends north along the flanks of this elevation, one hundred and twenty miles farther than it does. long the center. But let us put these fac's in another form. At Green Bay we fnd the blue limestone about on a level with' the water; near St. Paul it occupies about the same reltive position to the Mississippi; but through Wood an d Clark counties the azoic is in many places above where the blue limestone would have been if there had been no elevation there. If now we draw a line on an horizontal plane from the water level at the'Mississippi to the water level'at Green Bay, we shall find at each end of the line, there will be at least 800 feet of sandstone, and limestone between the ends of our line and the azoic formation below, while through Wood and (lhrk counties the azoic will stand not less than 200 feet above the line. Now if we sink our line doivwn io an horizontal plane with the azoic on each end of it, we shall find the height of our elevation above it in the above nanmed counties, which will be not less than a thousand feet. Here one hundred and twenty five miles to the north of the lead district, we find a continuation of the same north and south elevation, and gaining in height as we extend north. While, on this trip, I male a hasty visit to Lake Superior, by way of Duluth and Bayfield, to where this north and south elevation would intersect the lake. Reaching the shore at Ashland, 1 extended my observations south about twenty miles, near the west line of range 4 west. This, as you can see by the map, is near our west line of the lead district. From this point I extended my observations east towards the fourth principal meridian, through an almost impenetrable forest. ) fLund here the same geological arrangement of parallel ridges, with just the same bearings as those in the lead district, and all dipping down and dying out as they extend west. Here we are altogether in the azoic formation, with the strata very much disturb. ed, consequently it is impossible to judge as accurately as where we have undisturbed rocks for our guide; and furthermore, at this point the axis we have been following north, forms a junction with an east and west axis of eleva:ion, known to extend from Labrador to the sources of the Mississippi. My object in going to this place was not so much to find out the evidences of this axis of elevation, as to find out if there are any lines of fracture, or systems of dykes traversing the azoic formations here, and if so, what their bearings are. South of Ashland the country is mostly covered with a very thick bed of marl, forming a basis for agriculture such as we seldom meet with, and supporting now a forest of which the State may well be proud, but hiding mostly her mineral treasures and their phenomena. It was not until I reached the base of the Penokee elevation, along the Bad Ax river country, that I could get a good exposure of the rocks. But along this region and to the eas6 of it, good exposures of the strata are occasionally met with. In but few places where the azoic rocks are exposed as the surfac rock, do we find stronger evidences of mechanical disturbance, and. long continued exposure to heat, than here. The mechanical forces, however, by which these strata have been brought up to such an angle, do not seem to have acted with great violence, btit to have acted through'long periods of time. The rocks are not fractured, as in many places, and the systems of dykes are mostly (as far as what came under my observation) running with the strata, and between the different beds, crossed by smaller veins cutting the strata at right ang'es. At cne of the falis on P ad river, there is a beautiful exposure of trap, conglomerate, and other members of the azoic formation These different beds are almost perpendicular, and have a bearing ahlost nortL and oouth. Where I could get a good siget with the compass, the bearing was about north, ten degrees east. Between the trap here, (which is a beautiful amygdaloid) and the conglomerate, there is wvhat a Cornish miner would call a great cross course. It is from 30 to 40 feet wide, and the order of its formation and filli.g is as follows: The trap presents a regular smooth wall, as fine a specimen of slicken wall rock as we usually find in a true fissure vein. On tLis wall is a very fine grain fluccan, from four to six inches wide. Next to this flucan is a soft blue and red Lish clay passing into a soft clay state, with bunches of sale spar, laumonite, prehnite, and other minerals of this character. 2 I give this as a specimen of the lines of fracture that traverse the azoic here, and certainly this is one of the places whero nature permits us to look.upon the results of mechanical and chemical forces in their normal condition. Where she draws back, as it were, the covering that. hides them from our view in the lead dis. trict, and invites us to exanine the forces and conditions that resemble, (if not the same) those that underlie the phenomena there. The details of my observations on this trip are now being published in the Darlington Republican, and the Dodgeville Chlron icle, and I mill only add here, that the geological position, physical conditions, and various other indications of mineral strata found here, are such as would lead un to suppose that this is one of the most likely places in the state for large and extensive ore deposits. At the Penat tee elevation, vast and almost inexhaustible beds of magnetic iron ore stand exposed. Along those belts between this and the lake, good specimens of both lead and copper have been found, although the country is almost inaccessible to explorers, and I have no doubt that when a systematic investigation is made, either by the state or private enterprise, that other minerals will be found, especially on the south side of the Penokee elevation, such as gra, phite, gypsum, aiatite, or the native phosphate of lime, and other minerals of this class, now so much needed by the state for agricultural and other purposes. l-oSving followed out this class of phenomena to such an extent,,I will return to the lead district But before I do, I would like to say that these phenomena, such as an axis of elevation, across which belts of mineral land are found at right angles, are no new features in mineral strata, but are the common, though very important. features of old and long established mining regions. As'on evideoce of this I will introduce one or two examples here..In Von Cottas' Treatise on Ore Deposi's, page 427, we have the mnsing district of Cardigan shire, WaleXe, presented in the following language: "Cambrianeclay slates, and related rocks, predominate on the west coast of Wales. These slates are not disturbed by igneous rPeks, and contain numerous lodes at the boundaries of Cardigan shire and Montgomeryshire. The district containing them is about 40 miles long by 5 to 22 miles broad, extending north, northwest to south, southeast; and lodes as as a rule, strike east, northeast,' west, southwest; consequently almost at right angles to the lougest axis of the entire belt." In another place in the same report, the writer has classified these lodes into six groups or belts. in the geological arrangement of this mining district, and the lead district of this State it is impossible not to notice a very striking similarity. Along this axis (which is nearly north and south), there is no disturbance of the strata by igneous rocks, and yet a persistent course is maintained for 40 miles, with belts of mineral veins crossing it at right angles. It is impossible also, not to notice that such geological arrangement is the result of some general law, underlying mineral strata. I will here introduce another example, on a more extended scale. I have before me a geological map of England, and Wales, by Bakewell. If, by this mtp, we look along the western coast of England, and Wales, and from thence into Scotland, we observe a tract of land along which the mines of these countries are found. Alongthis tract we have some of the oldest mines in the world, Mines that were worked ever three thousand years ago, and were visited by the first commercial nations of antiquity. We have here also some of the best defined fissures, and mineral veins in the world; fissures and veins that have been fully developed, and their characteristic features are marked and destinct. In no other mining region are those systems of g-ouping into belts, and districts, more distinctly marked. Suppose now, we go to the western part of England, and drive down a stake at the extreme northwestern part of Lands End in Cornwall; and from that take measure about seventy, or eighty miles east, anddrive down another, (that will be about the width of the lead district of Wisconsin.) Now let us draw two lines f'om these stakes north to Scotland, a distance of three hundred miles or more, and then see what will be included within those boundaries. We have all the mines of Cornwall, Wales, Anglesea, and the Isle of Man on the north. South from Lands End, our lines cross the English channel and strike a belt of mineral land on the westernmost Fortion of France. " This is a belt," says Von Cotta, "lying north and south, whose northern prolongation touches the tin districts of Cornwall." If we are curious enough to follow those lines still farther soutb, by takig a good map, we can see that these lines, after cr,;ssing the Bay of Biscay, strike on to the north coast of Spain in the province of- Santander between the western portion of the Pvrenees and the sea, and include the extensive lead and zinc mines of that province. I refer to these facts, (1.) Because they are plain and open for inspection; any man with a good map can trace them for himself. (2.) Because they prove beyond doubt that this system of group~ ing is not a mere accidental occurrance in nature, but the result of some general law with which mineral veins are always connected. (3.) To show that this law is not limited in its operations to one ore district, nor to one province, nor to one island; nor to one' bed in the strata, but is operative throughout this vast belt of m ineral districts from Spain to Scotland. (4.) To show that its seat of action is too deep to be disturbed by the waters of the ocean, or to be reached by til ai'ts of mining. Har;ng now sa.tisfieod myself fully of the existence of an elevation of land running north, and that this elevation was a line of physical disturbance along which those belts of mineral land in the lead district were arranged, I felt confident that the northern boundary of the lead district had not been reached, hence I commenced a sys tematic inve;tigation of the strata north from the last belt. of mineral land in town six. TAwo important considerations led me to do this, (1.) It is usual for mineral districts formed like this, with east and west belts crossing a north and south axis, to taper out gradually, that is the ranges would become smal]er, the ore deposits scarcer, or the ore more mixed up with other material. Having noticed instances of this kind before, in well developed mineral districts, along well defined axis. aLd knowing that these things are governed by general laws, I looked with a great deal of confidence for a mineral belt of some kind north of the old boundaries of the lead district. (2 ) The strata of the lead district crops out here, and if another belt is found, it must be in the sandstone, or below it. It is no easy matter, however, to discover a belt of mineral land where no excavations have been made. Those in the lead district were not noticed as belts till the present survey; and it is a question whether they would be noticed now, but for the mining excavations made along their course. In this, my Report, on the region directly north of what was supposed to be the boundary line of the lead district, I will call attention to a class of phenomena, somewhat different from that already described in my Report of the lead district proper. The well defined belt of mineral land in town six, and supposed to be the last belt of the lead district north, is found along the southern flank, (and in.some instances) near the summit, of an elevation. or ridge of land running from near Prairie du Chiea on the west, to ]Blue Mounds. on the east, a distance of sixty miles, or more. This ridge of land runs parallel with the belts of mineral land in the lead district, and has the same eastern, and western, extension, And what is also very remarlkable here is, the Wisconsin River, about 10 miles to the north of this ridge follows the course of this ridge, along its whole length, but when ccming against the north, and south lit e, on the extreme east side of the lead district, at which the mineral belts, and this ridge gives out, it bends around to the ncrth of east for a short distance, then turns nearly west, until it reaches the same line; and from this place continues its course north through the state, along the east side of this. north, and south axis. Now whether we must regard these faers, (that is the course of this river, now along the north side of this east and west elevation, and then turning at the line, at which this elevation gives out, and following along the east side of this north, and south axis,) ar a coincidence, or a part of the same system of physical disturbance is a question for the future to decide, That the east and west elevation is a part of the same system of physical disturbance to which the lead district belbngs, will hardly admit of doubt When I speak of physical disturbance, I do not mean active vol. canic disturbance, nor active earthquake disturbanece, in the ordi. nary meaning of those terms; but a line along the earth's orast, where we have evidences of the action of mechanical and chemical forces that have been gently, (imperceptibly, it may be) lifting, disturbing and fissuring the rocks through vast periods of time, and filling those fissures with chemically deposited material. These, rather than active volcanic forces, are what we usually find in connection with mineral strata. To these forces we shall refer again in connection with mineral veins. Commencing my examinations t) the north of the lead district, along this east and west elevation, my attention was first directed to various basin shaped depressions, or what is usually called by the miners sink holes. If the rocks were of volcanic origin I should not hesitate to call them vents; or if it was in the organic formation, I should pass them by as chimney like perforations peculiar to that formation; but in sandstone and limestones their origin is not so easily accounted for. But that they bear some relation to this systemrn of physical disturbance I have no doubt. These sink holes do not appear to be confined to any one part of this elevation or any one geological formation. I have noticed them through almoas its entire length. In one place where a branch of the East'Peccatonica cuts back into this elevation in town six, range four east, I counted'as many as ten of these sink holes on about a section of land, some of them ten,, others fifteen feet deep. Mr. Thomas Strutt, a farmer living in that neighborhood, told me that in the spring, when considerable water falls and flows into these places, he has known the bottom to give out, or sink aown several feet. What is very interesting in ccuncction with this place is, these sink holes are found about the center of the mineral belt on the south side of this elevation, and are cutting down into the lower magnesian limestone; and from the fact that the water pDsses freely through them, they must be connected with the strata -below. To the north of this place, and a little to the north of the center of the elevation, we find sink holes in the upper sandstone, or the St. Peters' sandstone as it is called in books and where the strata thickens we find them in the Galena limestone also. About sixteen miles to the west of this, in town, six, range two east, and about four miles to the north of the village of Lindon, and on the summit of this elevation is a very noted sink hole. It is about 225 feet long, 125 feet wide, and from 25 to 30 teet deep. It is now a pond of water, the lower portion having been filled with clay, soil, and other material washed into it from the surrounding country. Mr. I. U. Baker, an old resident there, told- me, some time ago, that twenty-five years ago it was not filled as it is now, but was open for a great many feet deep. IHe stated also that when water flo-ed into it from heavy rains, it would find its way in a very short time in its turbid state to his spring a distance of nearly a mile to the north. There is a point here worthy our attention The place where the water enters this sink hole on the sutmmit of this elevation, is almost on the top of the Galena limestone; where it comes out at the spring, it is between the lower bed of the blue limestone, and but a very few feet above the sandstone,. giving us at least a vertical depth of 250 feet. Unless this sink hole extended through the whole of these strata, we cannot ccnceive h:w this water, in its turbid state could possibly find its way in so short a time to such a depth; especially when we consider that the lower beds of the Galena limestone, and the upper beds of the blue (strats equally favorable for the escape of water) crop out above the spring along the side of the same hill. There are many other sink holes along this elevation, of considerable interest, especially those at the West Blue Mounds. Approaching the mounds from the west, these sink holes seem to converge as though they would center in this elevation. Ascending the Mnound from the west side, we fin]l, about half way from the base to the summit, two or three sink holes near each other. One of them of considerable depth, showing a ledge of rock, at least twenty-five feet. On the north side and nearer the summit, instead of sink holes, we find slight depressions, with a damp, marshy surface, while on the cast side, near the summit, and full four hundred feet above the surrounding country, we find several never-failing springs of water, The -West Blue Mound is 1,150 feet above Lake Michigan, or near 1,800 feet above the sea, and is one of the highest, if not the highest, point of land in the State of Wisconsin. To suppose that this large malsh on the north side, and near the summit, and from whicb s cut several tons of hay every year; and those springs on the east side, a little higher up, are supplied with water from w!qal falls G;, the summit of the mound, is the extreme of folly. To account for the water that supplies these springs and this marsh land, at this altitude, but'two other ways are left us. One of these is hydrostatic pressure, the other is mechanical force acting from below. If a body of water can be found at this altitude, or above it, with a possible connection with those springs, then this body (f water will be, in all probability, the source. But if such a body of water cannot be found, then our only chance is to accept the latt. r as the cause. This key will doubtless explain most ot the phenomena along this elevation of land, and perhaps throw considerable light on our mineral veins, but I forbear using it for the present. There is another class of phenomena that I would briefly refer to in connection with this, topic, and which bears perhaps a closer relation: to it than we may at first suppose, namely, the chimney like perforations that we sometimes observe in the standstone. This class of phenomena is noticed only by a close observer; in fact the chances for observation are few, for this rock is exposed only at its outcrop along the streams. Where the rock is opened as a quarry, we sometimes meet with good examples, These perforations (or what were once holes in the sandstone made previous to its consolidation) resemble very much the perforations in the Azoic formation, with this difference; the former are filled with the same material, sand; while the latter are usually filled with foreign material, or matter in a different state of crystallization. These perforations vary in size from a few inches to two or three feet in diameter. They are always filled with the,ame material as the rock in which they are found, but when the rock is removed, the filling sometimes remains like a pillar of sand stone, cast in a mould. A good specimen was found some time ago at Mineral Point, and is now in the possesson of A. J. Cooper, Esq., of that place, whose good nature will lead him, we hope, to-make a donation of it to the Academy of Science, where it will find its place among other specimens from the lead district. Such specimens are seldom met with, for it is only where the sand rock has obtained a certain degree of hardness, that specimens of this kind can be fcund. Where it is more friable the impression only is found, reminding one of some ancient volcanic vents, that are not only extincet, but filled with, and buried in their own ashes. Where the rock is sufficiently hard to retain its form, the filling separates easily from the mould, and the mould has the appearance of a channel, or pipe through which water had been forced, either from above downwards, or from below upwards. The sides of these channels or pipes seem sometimes almost vitrified, as though the water passing through it was at a very high temperature, and continued passing through for great length of time. All things conaidered, it would seem that the passage of this water (if it was water) was from below upwards, in the shape of thermal waters. It may be premature, with the limited amount of information in our possession, to attempt to explain the origin of this class of phenomena. or its relation to other classes of phenomena connected with our mineral veins; but it certainly justifs the presumption that they belong to a class of phenomena that will, when the details are worked out and clacsified, establish the dependence of our mineral veins upon the physical forces that have acted upon these min cral strata from below. And certainly it justifies the conclausion that these are evidences and manifestions of mechanical forces, (whatever may have been their form), that have caused the physical disturbance along those lines already referred to, and with which our mineral strata is connected. It may not be just in the right place, but I would like to introduce here,;wo or three pages of theoretical considerations, in connection with the phenomena alreadypr ese.:: td, It will enable us the better to understand this, and propar- our minds for further investigations. The evidences of mechanical, and chemical forces, acting along those lines of elevation, and belts of mincrnil land, are so mal ifold, and convincing, that no scientific man will I thir.k, question their existence. And although it may be difficult to demonstrate, that these forces were generated by internal heat, yet every class of phenomena points in this dirtection. In the absence of demonstration, or positive proof, let us arrange the information in our possession, with a view to the explanation of these phenomena. The natural position, or lay, of the strata through this pait of the state, as will be seen represented by my map, is a gentle elevation to the north, consequently a gentle dip. or declivity to the south. Hence we'find that the series of stratified rocks is gradually growing thinner from the south to the north, until the lowest bed,' (the potsdam sandstone) which is in the southern part of the state covered with at least six hundred feet of lime rook, becomes the surface rook a little to the north of the lead district. And as -e travel from the south to the north, we see that the various beds of the different formations, become the surface rock in regular succession. A few miles only, to the north of the lead district, owing to the dip of the strata just alluded to, the azoic, and plutonic formatiorns become the surface rocks. These in the southern part of thhe lead district, are covered by at least a thousand feet of stratified rocks,; Not to notice fissures in the rock, and the fact that water would find its way through them to the lower fornmations, water would certainly enter between the beds of these outcropping strata, and find its way down this gentle declivity, as naturally as the waters of the Wisconsin and Mississippi flow towards the ocean. Especially would this be the case with the lower bed, the postdam sandstone, which, where not exposed to atmospheric action, is but little else than a bed of sand, through which water passes freely. Now let us suppose-and the facts will justify not only the supposition, but even the conclusion-that the elevation referred to, and the belts of mineral land in the lead district. were formed over groups of fissures,& or faults in the plutonic and azoic rocks beneath, consequently over lines of fracture, produced by mechanical force, evidently gecerated by internal heat. The water entering between the beds of the out-cropping strata as above referred to, and following down its gentle declivity, would necessarily intersect those faults or fissures along their whole line. Here water would come in contact with intensely heated matter, under a pressure of several hundred feet of rock. This would certainly be one of those places where chemical and mechanical forces would be generated; such as we know must have been active during the physical disturbance along those lines referred to, and the formation and filling of mineral veins. If the temperature along those lines of fracture in the plutonic rocks were surmeient, the water gradually or suddenly reaching the heated matter as described, would be converted into steam, or elastic vapor, whose mcohanical power and properties we understand. During the early formation of these stratified rocks — say for instance the potsdam sandstone-the resistance would be comparatively little, veLt would be easily found through the loosely accumulating sand. Put as layer after layer was added to the strata, and the more compact limestone began to form and har4en above it, resistance would increase, until, to overcome it, a general lifting of thbi strata would take place, by which escape would be effected through fissures in the ock along the line of those original faults in the plutonic rocks below. These fissures in the newly formed aqueous rocks, we must regard as the results of the same mechanical force acting upvn this strata from below,' hence their conformity to directive influences, hidden from our view. When we take into consideration the great antiquity of the lower strata of the lead district, and how that it commenced.t the closing of the azoic period, when the temperature was supposed to be too high to admit of organic existence, and its vast fissures even then the outlets ef radiant heat; nothing is. more reasonable than to suppose, that for untold ages the strata above these foci of mechanical power, would be traversed by heated waters, forced by elastic pressure from be],w,. through every crack and fissure in the rock. This water would sometimes find its way through vertical fissures, at other times between the thin beds of the strata, seeking, as such power will always do, those places that give the least res:staneuo; and bringing up doubtless at the same time, in solution from depths unknown to us, the elements of that material that formed our pres. Chemic- 1, as well as mechanical activity and force, would also be conspicuous and powerful along those lines. The solvent powers of heated water, aided as it would be by material held in solution, at various degrees of temperature, would become of itself a chemical agency of great force, and the result would be chemical action, and reaction all' along its course. What I would notice here especially, is, that physical conditions, such as would seem to be generated by the arrangement of the above facts, and considerations, would not fail to produce the forces I have referred to, And that sueh f;rces, both chemical, and mechaniical, would not fail to produce physical disturbance along the line.of strata in which and on which they act. And that such disturbances would not fail to produce phenomena that would correspond to their action, and that would possess features by which we might possibly recognize their caus;e. It is now a well known, and a well established fact; that afl natural phenomena possess, and present, (more, or less.. distinctly) the evidences, and material for their' own exolanation. Ii thbe, in;he light furnished by the arrarngement- of the above facts, and considerations, the phenomena of the lead district begin to assume forms, and features, by which we can;recognize them as the results of physical conditions such as are described above; in the absence of other conditions to explain them, it is perfectly legitimate, and safe to follow this:light as far -a. it will lead.us. 26 With this momentary digression, I retlurn to pursue ag;-in our investigations along the north side of the miningt region. On the north side of the elevation, along which the sink holes are found, the surface is very much broken, and declines rapidly towards the valley of the Wisconsin River. The streams also flowing into this valley, cut back into this elevation, in places almost to its centre. This ralid declivity of the surface to the north, anti the gradual dip of the strata to the soulth, brings to the surface on t'l north side of this elevation, the strata of the lead district; that is, the rocks in which the mines have been worked, and lets us down on the lower strata-that is, the rock that underlies the min es of the lead district. Here we find ourselves on a platform at least 400 feet -below the surface of the lead district, and on rocks that were formed long before the rocks of the lead district had any existence. This,too,places us back in the history of the past to a period when the temperature of the cooling crust of the earth, and other physical conditions were very different from what they were during the formaton of the rocks of the lead district. There are but few things in geological investigations of more importance than to be able to distinguish between physical conditions peculiar to one period of geological formation, and those common to many, or to all. We cannot have too deeply impressed on our minds the fact that, in entering upon the investigation of these strata, we have to investigate rocks of more ancient date, formed in a period vastly remote. We are no longer delighted with the fossil remains with which the liniestones of the lead district are crowded At this period, the waters of the primeval ocean rolled over our continent, save here and there a narrow strip of land on which life had not yet began. And even the physical conditions of the sea were such that life had but just a begirning there..I lonely trilobite might, now and then have been seen lingering near the shore, or a tiny little singlo clinging to the rock, but beyond this the;.-e was no sign of life. This was e-phatieaily the.age of crystallization and mineral formations, the highest and most beautiful forms of matter before organic forms appeared. As we descend the northern p f th:.s elevation, and commence our investigations in these low:r, and older formations, we find that the character of the rock is different, although very similar physical features mark the strata, as though the. had been subject ed to the same, or very similar physical conditions. Before we get quite to the middle of town seven,-the rock, clay, and even the soil, in many places, begins to wear on ochrey appearance, which continues more or less for a distance of three or four miles. When this first attracted my attention, I treated it lightly, supposing it to be the outcropping of the north and south ranges of fissures in their northern extension, and regarded it more as an evidence of a north and south axis then anything else. But noticing it in several places to the east and west of where I first discovered it, J began to entertain hopes that these ochrey out-croppings were indications of another east and west belt, similar to those in the lead district. With this impression I commenced a systematic investigation of the surface indications both to tLe east and the west. But along a region of country covered mostly with timber, and underbrush, where the tops of the ridges were covered with several feet of clay, and their sides hid, fro:n the summit to the base with broken, decomposed rock, it was not a very easy matter to obtain the necessary information to settle this question. By plaoiiig on a map, however, these oehrey outcroppingis, and their surface indications, similar to those noticed in the lead district, I succeeded satisfactorily in making out aline of physical disturbance resembling very much the other mineral belts. By ochrey outcroppings, I mean those places along the surface that may be distinguished from all other places, by a reddish, or a reddish brown, clay, that is almost always found over ploductive mineral:ranges in the lead diEstrict. Nor is this peculiar to the mineral strata of Wisconsin, but is found in other mining regions. This peculiar ferruginous feature of the clay, is the result, no doubt, of the decomposition of the iron, or iron pyrites found in the fissures of the rock decomposed to form the surface clay. A belt of land strongly marked with these and other features, peculiar to the surface indications of the belts of. mineral land in the lead district, I found extending through town seven, from the township of Hickory Grove, in Grant county, to the township of Cross Plains, in Dane county, a distance of about fifty-five miles east and west. This belt varies in width from four to six miles. The mines of Highland, and Centreville, (we have always looked upon, as an exception to the general rule, found on, as we supposed the northern extension of the north, and south ranges, rather than forming a part of a new belt to the north of the one in town six) are found on the western extension of this belt, in the townships of Highland, and Blue River. But so far as we can judge from surface appearances, the mineral wealth of this belt will consist mainly, in the large, and rich deposits of the oxide of iron that it seems to contain throughout its entire length. Where these deposits appear at the surface, we find the ore existing in different statesKor conditions. In some places we find the out-croppings of what seem to be large beds of very impure argill aceous or slaty iron ore; affording, however, in places, go)d specimen uf1 purer varieties, which, to me, looks like indications of purer beCds beneath tCo se surface out croppings. This slaty variety decemposes reaily;nto a reddish brown clay, in which we sometimes find beds of ochre, varying froim a few inches in thickness t9 severa feet In these beds of ochre, we sometimes meet with separate a.d distinct colors, of brown, reddish brown, bright yellow, yellowish brown, and sometimes layers of pure white clay, that look like chalk. It is certainly very difficult to account for this':ariety of formand color, unless it be by a process of seggregation, and aggregation, set up by strong ehemscal actin., These argillaceous or slaty beds. are found mostly either at or very near where the potsdam sandstone below, and the St. Peter's sandstone above, unite with the lower magnesian limestone In the sandstone, both in the Et. Peters, and Potsdam, where it is free from foreign matter, (that is lirae, clay, and the like), this ore assumes other forms. RWhere there is a good exposure of this rock, and especially, where it has been exposed to atmospheric agencies for a great length of time, it assumes a banded structure. These bands are not like seams of iron ore, that we sometimes meet with, spread out between beds of sand, as though it was the result of deposition from water, but they resemble more the bacnde, structure ofwood, shown in a transverse section of a tree. These bands are sometimes very much contorted, as though they were bent by, heavy pressure, while the sa}! dstone remains perfectly undisturbed. In the iron belts of lake Superior, a similar banded structure in the Potsdam sandstone was noticed by Pioster, and Whitney, and in their report on this peculiar feature of iron ore in sandstone there, they,,ay, " We know of no theory which affords so probable an expla nation of this structure, as that b5, which the action of seggregating forces is brought into play." Another, and I think the most important form in which this oxide of iron is found along this belt, is that of a bright red oowder. In this condition itis sometimes found:n rcgular flat oIenings in the sand rock, mixed with a very pure, coarse grained sand, but oftener disseminated through the mass in the shape of a cement. In this condition it varies from a ferruginous, or irony sandstone, to a sandy ochre. The richest deposits, however, are found along ranges of fissures, or -more especially where ranges of different bearings intersect each other. These points of contact are the richest places, and seem to be centers from which this material diverges, gradually growing poorer as the distance from them increases. Where the oxide of iron in this form is most abundant, the sand-rock is very coarse, and very friable, and easily reduced to its original grains. ~This oxide of iron is not chemically deposited in the sandstone, that is, it has not a crystalline texture, it is easily separated from the sand by washing it in water. Water takes it up very readily when it is stirred, and allows it to settle readily when undisturbed. When separated in -tni way, and dried, it is a very fine red powder, as fine as the oxide of zinc; and when mixed with, or ground in oil, it will make paint of a brilliant red color, that will make as fine a finish on wood as either zino or lead. Since I first discovered it in this form, (that is since last July) I have been experimenting 29 on it as a paint, by exposing it to the extremes of climatic coinditions. Thus far it does not, seem to be effected by beat or cold, wet or dry, any more than the best qualities of lead or zinc paint, under the same condition. The brightniess of its color, that I at first feared would not st;ard light and moisture, remains thus far unchanged, or if changed at M11, it is a deeper red. As a pigment, this material is equal, if not superior, to anything we call ochre, or mineral paint, and if its durability should prove to be, when tested by time, what it appears to be under experiment, it cannot fail to be valuable, for it will take the place of lead and zinc paint for most out-door work, and common buildings. And if in this form it will furnish material for paint of a bright red color, that will put on a finish as fine as lead, and that will be as durable, or even approximately so, and can be furnished for less than one fourth of the cost of lead, i) certainly must beo as valuable to the State as lead itself. lVWht our State is most deficie t in for manufacturing purpo es is fuel; and any material that can be manufactured into useful commodities for commerce without coal, is specially important to us, hence valuable. The cost of coal and the exe onse of get ting it to our zinc mines, takes off a large portion of what the zinc is worth, when prepared for the market, consequently renders our zinc deposits comparatively worthless. This form of the oxide of iron car be obtained along this belt, and prepared as a paint for the market, at % very trifli,g expense, except labor. It is found in ledges of sandstone, drained by deep valleys cutting back into this ridge, and exposed in places from 80 to 100 feet in vertical thickness. It can be obtained from the ledges without the ordinary expense of mining, and separated from the sandstone by water, which most of the valleys wilt supply. The process is simple, the expense trifling, and cost in fuel nothing. Labor, common labor, (not coal and costly machinery,) is all that is wanted to manufacture this into' paint and prepare it for use. Anything that will give us a cheap durable paint, manufactured by our own labor, and from our own raw material, without the expense of coal, must be valuable to our state. And viewed in this light, and with these advantages, I am disposed to think that this belt of mineral land, along which these deposits of cohre, and oxide of iron are found, will be equally valuable, perhaps more valuable, than if it had been another belt along which deposits of lead and zinc were found, similar to those belts in the lead district already referred to in this report. As to the origin of these deposits of iron ore along this belt there seems to be E at one way of explanation open to us. The fact that they are found in the lower, as well as in the upper sandstone,,and that too where the sandstone is covered with 150 or 200 feet of limestone, (such for instance as at Mr. Ruggle's place on the road. from Arena to Dodgeville,) cuts off all chance for explanat 30 tion by surface agencies, such as is sometimes found in connection with deposits of bog iron ore. And again, the fact that it is found in connection with ranges of fissures. and especially -rich at their points of contract, would indicate a very different origin. At Centreville, in the township of Blue river, there is a rich de posit found in connection with a range of fissures cutting through the bed of sandstone. These fissures may be seen at the he4i of a valley which is evidently formed along their line. Ore:f itheose fissures has a regular wall, with what is sometimes called a sliktan side, it has a smooth fine, polish as though it had receivecl a vitre.ous coating Fut on by a glazier. From this leading fis;:-re the sandstone pitches to the south in thin friable layers that will crumble in the hand, and is highly-impregnated with this oxide of iron for a great many feet each side of it, and as far down as the sandstone is exposed in the valley. This is one of many places along this belt, as well as many others through the lead district, that must settle for ever the fact, that the sandstone of the lead district has been acted upon, and fissured by mechanical forces ifrom below. And when we take into consideration the fact that these deposits are found deep down in the potsdam,. (as well as in the sandstone above) and that too at a point not far above the azoic rocks; and when we consider farther, that similar, and parallel elevations not far to the north where the strata is still thinner, and not many feet of the sandstone left on the azoie, masses of iron ore are found protruding through these few feet of sandstone, such as at Ironton in Sauk county, on the western extension of the Baraboo elevation, an elevatioi, along which we have unmistakable evidences of nietamorphic action in. the quartzites; and when we consider still farther, that to the north of the Baraboo elevation, where the azoic rocks come to the surface, thev present parallel ridges, and along the cen tre of some of them we find long ranges of iron ore conformint in their bearings, and extensions to these belts of oehre, and oxide deposits we see there is good reason, indeed every reason to suppose they have their origin in physical conditions acting from below. This supposition ripens almost into demonstration, when we c-qn. sider, also, the peculiar adaptation of the azoic rocks, and the physical conditions that prevailed at the period of their formation favorable to the formation of iron deposits. This subject is plesented in Foster, and Whitney's Report of Lake Superior, better than I can do it, consequently I will introduce a portion of it'-ere: "We may conceive that the various rocks of the azole series were originally deposited in a nearly horizontal position, ata period prior to the appearance of organic life upon the earth; that these stratified deposits'qre compost d, for the most part, of finely ccmminu!-d materials, principally silicious and argillaceous, in some csaes consisting of almost pure silex, like the purest portion of the potsdam sandstone which was afterwards deposited upon these strata. "During the deposition of these strata, at various intervals, sheets of plastic mineral matter were poured forth from below, and spread out upon the surface of the pre-existing strata. These igneous rocks are exceedingly compact, and uniform in their texture, which would seem to indicate that they were under heavy pressure, probably at the bottom of a deep ocean. The same depth of water is also inferred from the comparative absence of ripple-marked surfacbs throughout the whole series During this period, the interior of the earth was the source of constant, emanations of iron, which appeared at the surface in the form of a plastic mass in combination with oxygen, or rose in metallic vapors, or as a sublimate, perhaps as a chloride; in the, one case it covered over the surface like a lava sheet; in the other it was absorbed into the adjacent rocks. " In the closing remarks of the same report on the origin of the iron deposits in the azoic rooks of Lake Superior, we have the following conclusions: "On the whole, we are disposed to regard the specular and mag. netie oxides of iron as a purely igneous product, in some instances poured out, but in others sublimed from the interior of the earth. The suppositicon cterSained by some, that it may be a secondary product, resulting from the decomposition of the pyritous ores, or from the metamorphism of bog-iron, is inadequate to account for the accumulation of such mountain masses, or to explain its relations to the associated rocks. "Where these cres occur in a state of almost absolute purity, in the form of vast, irregular masses, occupying pre-existing depress sicns; or, where the incumbent strata are metamorphcsed and folded over them; or, where they are traversed by long lines of ferruginous matter in the form of dykes-there can be little doubt that these ores have risen up, in a plastic state from below. "Where they are found impregnating metamorphic products, such as jasper, hornstone, or chert, quartz, chlorite and talcos slate, not only interposed betweetn the laminXa, but intimately incorporated with the mass, giving it a banded structare, we are disposed to regard it as the result of sublimation from the interior.,"Where they are included in metamorphic strata, in the form of beds of variable width, with a conformable range and dip, ancd with minute particles of the associated rock mechanically mi ed with the ore, we are disposed to regard them as the result of aqueous deposition, although the materials may have been derived from the ruins of purely igneous products "-Part II, pages 68 and 69. What is true of the azoic formation at Lake -uperior, is true of' it the world over. During the deposition of these strata, the interior of the earth was not only the source of constant emanations of iron, but as much so of all the other metals. It was a period in nebular condensation, when the crust of the earth had become too thick and dense to cor duet its radiant heat into surrounding space, hence it was thrown into those lines ef fracture peculiar to these strata, which were then the safety valves of a cooling world. Who among us that knows anything about mines or mineral. strata, but is aware of the fact that the lower silurian rocks are the mineral strata of the world. And why? Because its lower members are formed over the azoic rocks, and over these lines of fracture, and consequently must have received these metallic emanations, a large portion of which must have teen thrown down by chemical deposition in its passage through the fissures of these rocks. If these deposits of iron were found in rocks whose geological position was thousands of feet of above the azoic; a nman might be pardoned for locking for their origin in physical conditions, or forces acting from above. But here in the lowest member of the Silurian series, within a few feet of the azoic rocks, and with the impress of their lines of fracture on the rocks before us, it is filiy in the extreme to look for any other origin. I would ask pardon myself for dwelling so long on this subject, but for one thing, and that is the relations of these deposits to the deposits of lead and zinc in the lead district, are so clearly defined as to make their common origin certain. It, is in fact a ontinuation of the same ore district, with iron ore predominating. The outeroppings p f these deposits of iron ore, I have traced along a belt of land 55 miles long, east and west, and from 4 to 6 miles wide, consequently it will add near three hundred square miles to the ore district of Southern Wisconsin. Since attention was first called to this discovery in JAly last, one company has been formed to manufacture these oehres at Blue River, and have their factory now in working order; and have, I understand, several hundred tons of this nmaterial ready for the market. From a letter just received from the p.rties, I find they are now arranging to run their factory by water power, which will enable them to manufacture 6 or 7 tons per day. A. letter received from other parties farther east on this belt, informs me that arrangements are being made to manufacture these oehre3 there also. I have no doubt but that an impcrtant branch of industry will spriug up in connection with this, that will employ a great nan) men, and be a source of profit to the state, and all concerned. Thie is tle first installment of the practical results of following out this system of grouping along this north and south axis, that will, I trust, be doon followed by others. There are evidences of another parallel belt still farther north in town nine, good specimens of lead ore are found on it at Orion, in Richland county, I have no doubt when the' details of this belt are workled out, important deposits of some kind will be found there also. 33 SANDSTONE. The character of the rocks in which the mines of the lead district are found, and to which they have been confined, is familiar to the miners, and needs no farther description in this report. But the character of the strata that underlies the mines and their adaptation to mineral veins, is what; is especially called for in the present stage of our mining operations. To this I wou!d call particular attention. Immediately undlerlying the strata in w hich the mines are being worked is a layer or bee of sandstone, varyiag from 80 to 100 feet in thickness,and separating the limestone of the lead district from' a bed that underlies it, known as the lower magnesian limestone. This formation is known as the St. Peter's sandstone. Few classes of rock require more care in determining their char. acters than sandrock. Sand, the world over, h's the same general appearance, and to identify it as sand requires but little Scientific or practical knowledge. But while there may be a very striking sameness in appearance, there is often an essential difference in origin and chemical composition. Sometimes we find sand to be the insoluble debris of disintegrated rock; at others, largely composes of comminuted shells ground to that state lby the action of water; in all cases fine particles of matter, which, when aggregated i.nd con. solidatd, is called sandstone. One peculiar feature of sandstone is, that when the cement by which the particles are held together, is destroyed, we can examine the original pirticles or graibs, apart from each o4her, and with a good microscope determine, to a great extent, their origin. This sandstone of the lead district, e-icept where it has for a long time been exposed to the atmosphere, is very friable, and in most cases can be crumbled between the fingers. In noticing this sandstone at first, I was much interested in finding some very reruarkable features. that I h: d not noticed in sandstone, with which I was familiar in early life. There was such uniformity, not only in the structure!f the rock, but in the grains composing it, that I was led to examine it carefully. In doing this with a small lens, I was surprised to find that the grains were pure quartz,'and very uniform in size. Not a pebble could I find, not a shell, nor any appearance of disintegrated rock; indeed, the grains of sand looked more like little crystals of quartz than anything else; and in submitting them afterwards to a closer microscopic examination, I was more than ever satisfied that such is the case. I srhmitted this ques'.on to the Wisconsin Academy of Sc'ences, Arts, and Let era, in July, 1870, and have since called the attention of other scientific men io it, and thus far found no objections. But fev things have interested me more than my microscopic examinations of these grains of sand, or in other words, crystals of quartz. I have observed among them not only almost all the forms *8 34 in which silica is known to crystalize, nilt some els.a in beauty to those larger crystals which can be examined without the aid of a glass. I have sometimes thought that I would give almoea. anything if I could procure some of those crystals in their magnified forms, as cabiner.snecirliens. Some of them are translucent, others almobt transparent. They have plane faces and regular structure, and their lustre is often beautiful. If it is true- and I believe it is so considered-that these peculiarities are the known and established rejults of chemical deposition from solution, an important field of inquiry is opened up before ucs. We would like to know-and it is important that we should know —how the water obtained the silica from which these crystals were formed. Was it dissolved out of d'sentegrating rocks above, and brought in solution in rivers, and streams that emptied themselves into the primeval oceai; or did the free elements of silica, like certain otLer elementary substances, rise in gaseous emanations with escaping heat from below, and become subsequently condensed ir. the fissures, and found their way in thermal waters to the ocean above, where entering intm chemical combinations they were deposited in the form of small crystals as we find thlem. Suppose Iceland should be submerged to a considerable depth be-'neath the ocean, and those plains, situated about thirty miles from thai, noted volcano, Hecla, known fnow to be full of hot springs, steaming fissures and boiling geysers, whose waters hold a large amount of silica in solution, that is now being deposited on the surface around tlhoe places, were pouring their waters into the ocean above. should we rnt have there, cn a small scale, -rhat perhaps existed on a very large stale during our sandstone formation. In studying eitber the sandstone or limest.lre formations that'underlie the lead district, we do well always to remember their very great antiquity; and also the fact that very different physical conditions prevailed then to what we find now, If ws look at my large map, we see that the potsdam sandstone, to which the layer that I hexve just been describing evidently belongs. although separated from it by over two hundred feet of li-estone, —is spread out over the upturned ridges of the azoic rocks, traversed, as we know them tc, be, where they become the sar face rock, with various faults and fissures, and chimney-like perforations. This formation, according to the opinion of scientific men, belongs to the most ancient of the strata which form the crust of the earth, and was formed prior to the introduction of animal or vegetable life on our planet; from which it is inferred that the temperature of our planet at that time was too high to admit of organic life. If the absence of vegetable and animal life at that period be an evidence that the temperature was too high to admit of it, then the formation of our sandstone must have commenced under the same physical conditions; conditions generated by degrees of tempera ture vastly above what we find existing on the: present surface of the earth. This view may also be strengthened with the fact that it is not until we rise to some distance in this formation, that any evidence whatever of vegetable or animal life appears. In studying the origin of the sandstone underlying the limestones of the lead district, on its relation to those strata, we should keep in view its great antiquity; and how, at that period, the crust of the earth must'have been comparatively thin, the temperature very high, and communications between the interior and exterior more frequent and more abundant. Viewing it from this standpoint, it is a question of no little importance whether the evidence is in favor of its having been deposited by chemical or mechanical agencies; and whether the material entered the primeval ocean through streams traversing the elevated surface alour, or in thermal waters through fissures traversing the earth's crust beneath. The potsdam sandstone below the lower magnesian limestone,and the small layer above it in its normal condition; that is, where it has not been changed by subsquent action, is only a loosely aggregated mass of quartz crystals, and as such is unfavorable for the formation of mineral veins. Because, in the first place, gases, steam or vapor, or water even, would pass freely through it without making a fissure;:nd secondly, if a fissure should be male through which heated water could pass, the water would soon dissolve the cement by which the particles are held together, and the result would be the filling of the fissure with sand. If we put so-e of this sand on a piece of glass, with a good reflector below it, and then examine it with a microscope, we can see how fieely water, even, could pass through it, and how unfit it would be in this c;ondition to present the necessary walls, or wall rock for a mineral vein. If mineral veins were fissures filled by in. jection, that is, melted matter torced into them in a liquid state from below, and consequently formed and filled at the same time, there would be no reason why mineral veins, or ore deposits might slot be found in sandstone, as well as in any other rock. But when we remember the fact that the material forming mineral veins is chemically deposited, and only where favorable conditions for chemical action are presented, such as a peculiar condition of the wall rock of a fissure, or the cap-rock of an opening, we see how utterly unfit a loose quartzose sandstone is for the formation of mineral veins. -int there is a point here too often overlooked, that we would do weil to consider, namely that mineral veins are seldom found in unaltered rocks, that is, rocks in their normal condition; buL usually, if not always, in rocks that have been exposed to metamorphic agen. cies, and that have undergone important changes since their original formation. Between the physical conditions producing those changes in the rock,. and the physicai conditions producing mineral veins, there is sometimes close relations. Like as the faTmer prepares his soil before sowing hs seed, so these conditions follow each other. A.nd as the farmer furnishes the elements lacking in the soil, Fo nature often furnishes the necessary qualifications lacking in the normal conditinri of rocks, by metamorjihic action. Every miner, and every man who has made mining his study, knows that it is the metamorphic, or altered condition of the rocks, not the norimal, that furnish the properties we call mineral-bearing. Hence wo find sandstone in.many parts of the world, under varying forms of metamorphic action, becoming metalliferous, or mineral-bearing. There are places, however, where sandstone, in its normal condition, and lacking the necessary qualifications for fissures, and mineral veins proper, is nevertheless to a. certain extent, and in a very peculiar teorm, metalliferous. The sandstone of the Blciberg (Lzad mountain), near Com. mern, in the Prussian Rhenish Province, furnishes an interesting example of this kind, Von Cotta, in his treatise on "Ore Deposits," gives us the following account of this formation: " The sandstones contain ores for a distance of about two miles, but are less rich towards their outer limits; the same commence near the surface, and extend with the strata to a depth as yet unknown.; it is stated that the m-talliferous strata are at times more than 45 fathoms thick. The sandstone is fil'ed, throughout its whole mass, with grains of galena, varying in size from a pin head to that of an apple, the coarser grains being the most rare, which are distributed with most surprisi:g regularity. Larger grains a"-e extremely rare; moreicomrmonly they decrease in size, so as to be barely visible. The interior of these grains nearly always contain fine sand, cemented together by galena. Frrom which it appears to me clear that the grains are not found in secondary deposits, which like a kind of alluvial depos't, have been only accidentally washed together with the sand; but that the ore was either formed contemporaneously with the sandstone, or penetrated it subsequently by a process of impregnation. From the forma of the cecurrence, it would appear to be an impregnation." "C. Haber," says the same writer,''has very recently described this lead ore deposit. He explains its formation by impregnations, which have penetrated from numerous fissures traversing the sandstone. Therefissures appear to be connected with true veins of galena, occurring in the Devonian strata beneath the sandstone." The writers above quoted, are not only good authority, but per. haps our best authority on all questions relating to mineral veins, and ore deposits; and their opinions should be received with a great deal of confiden'e.. If we adopt as a theory, their views as expressed above, in reference to the origin of that ore deposit in the sandstone, namely, that it extended by a process of impregnation, through fissures receiving their material from older formations below, we shall find that it -will explain very readily, certain phenomena found in connection with a' certain class of ore deposits 37 sometimes found in sandstone and limestone that have been but lightly disturbed. If thermal water rising through fissures in older rocks below, should penetrate a bed of loose quartzose sandstone, resting upno it, nothing would b. more reasonaile than to suppose, that such water, holding mineral mat'er in solution,-whether dissolved out of original veins below, or obtained from sublimations at greater depths, -would impregnate the sandstone along the line of those original fissures. And inasmuch as we find quartz and iron, quartz and galena, quartz and copper, and even quartz and gold in the same vein, there'is no scientific reason why they may not,-in the absence of proper conditions for forming veins-be associated in this way. Such a theory is well adapted to explain the phenomena of the sandstone of the lead district, and in but few places are the facts that support it better defined. If we follow along the line of the north and south axis already referred to, to the northern part of the state where these sandstones crop out, and the azoic formations be.,ume the surface rock, we shall tind belts of iron ore crossing this axis, at, or nearly at right angles to it. The Penokee iron range is a good ex.mple. Coa. ing south along this axis, to where a thin layer of sandstone covers the azoic rocks, these belts of iron ore are sees in places protruding through the sandstone. The well known deposit of iron ore, at Ironton,in Sauk county, on the western extension of the Baraboo hills, is a good example of.this. Still farther south, where the sandstone has its fullthickness, we find well defined belts of sandstone. impregnated with iron ore in various forms. These impregnated belts conform to the bearing of the iro - belts in the azoic, and cross the north and south axis in a very similarmanner. The close observer cannot fail to notice that there is a close relation between the belts of iron in the azoic formations, - and the impregnated belts of sandstone resting on these. formiations; nor can there be but little doubt that. the sandstone has been impreg. nated by solutions penetrating and rising through it from fissures connected with these iron deposits in the older formations. In speaking of the sandstone here, I include the two members of the Scries, the St. Peter's and the Potsdam. LOWER MAGNESIAN LIMESTONE. Immediately balow this sandstone, and separatilg it from the potsdam sandstone, is a bed.of limestone. about 250, or 300 feet thick. It is known as the lower magnesian limestone, and is de.,Etcribtd in the report of 1862. I shall notice it here only in its relhtioni to mineral veins. This formation says Prof. Whitney in his report, is almost entirely made up, everywhere in the valley of the Mississippi of an almost chemically pure dolomite, or a mixture of carbonate of lime, and carbonate of magnesia in the proportion of one atom, or equiv 38 alent or each,'jnemicaliy it is the same as the upper magnesian, or galena limestone, for dolomite is the same the world over. Dolomite, or miagnesian limestone seems to present very favorable conditions for the deposits of lead and zinc. TLe rich, and Sxtensive mines of Upper Silesia, Spain, France, Belgium, and various other places in Europe are found in this kind of rook. The Missouri lead, and zinc mines are found in magn esian lirtaatune o,cupying the same, or similar position in tho strata as the lower magnesian of this State. We may not know fully; consequently enarot explain why it is, that dolomite, or magnesian limestone, should present more'favorable conditions than other rocks with which it is associated in the same strata. Nor can we explain fully why it is that any other kind of rock should present more favorable conditions than every other kind of rock; and yet we know it is so. 4very miner is acquainted with the fact that a mineral vein is almost always affected more or less as it passes from one kind of rock into another. Sometimes a very rich vein, on entering a diferent (class or kind of rock, is suddenly impoverished; while on the other hand a vein may be pocr while traversing a certain kind (f rock, but when entering a rock of another kind, is suddenly enriched. This is a very co mmon occurrence in mining operations, and the miner soon learns o distinguish between a class of rock that is favorable for mineral veins, and one that.is not. And it would s.ve a vast amount of capital if this practical knowledge was more generally diffused amon those who have charge of mining operations. This fact, that certain kinds cf rock,. present more favorable conditions for the formation and filling of mineral veins, and ore depos its than others, has given rise to the idea, that certain roe s are o - Themselves metalliferous, or mineral bearing, while others are bar ren. An error has grown out of this idea that we wculd do well not only to notice, but to guard against it with care. Many seem to think, that if a certain kiad of rock is metalliferous in one place, like soil, it is apt to be productive every where; or if it is barren in a certain place, it is apt to be barren everywhere. We often hear men say I have no confidence in the lower magnesian limestone from the fact,, that it is barren wl ere it is exposed to view on the north of the lead district.., ould like to put a nail in this error right here, by saying, that, while it is evident that certain kinds of rock present, more favorable conditions fo- mineral veins than others. it is also evident that they are noe the cause, but the conditions that favor the cause by which mineral veins are formed. It is safe perhaps to say that mineral veins are always found in connection with physical forces acting from below; forces, in their origin independent of the rock in which the veins are found. And if one class, or kind of rock traversed by these veins is rieker in minerals, or ores, than another, it is because in this class, or kind of rock, these forces found more favorable conditions for ore deposits. It is only in the presence 39 of these forces that any kind of rock is n etalliferous, and apart from them every kind is alike barren. Suppose we apply the rules to the upper magnesian, by which certain parties have condemned the lower magnesian, maywe not with equal propriety condemn it with the same class of evidence? If, previous to the discovery of our lead mines, some one had been sent out to make a geological survey of what is now known as the lead district, an.d had commenced his work in Rock and Jefferson counties, to the east of those heavy belts of mineral ranges extending through Grant, La Fayette and Iowa, into Green and Dane, where the same kind of rock-the upper magnesian —is the surface rock; or if he had extended his exploration, even into Green and Dane, if he had confined his examrinations to the eastern side cf those counties, he would not have found anything that would justify him in pronouncing it a metalliferonus, or mineral bearing rock. Anemi if from this standpoint, within two or three mi.es of what has since proved to be a very rich lead district, he had pronounced the upper magnesian limestone a barren rock, from evidences afforded on the eastern side of the lead district, he would be e:titled to as much credit for sound judgment, as those who condemn the lower magnesian as a barren rock from evidences afforded on the north side of the lead district, for both are beyond the physical forces and condi. tions with which our mines and mineral veins'are inseparably connected. The unfavorable opinion of the lower magnesian, recorded in Prof. hall's report of 1~62, I have no doubt grew out of the teachings of this error, as we can see by reference to the report. The prircipat localities (says the writer, page 409) which have been quoted and relied on as affording evidence of the productiveness of the lower magnesian, are the Kickapoo and Olcking's diggings, near Franklin.'Ihese are the only places noticed by the writer, and only one of these he had visited personally. The Kickapoo diggings visited by Dr. Kimball, and from whose notes the writer obtained his information, is several miles to the north of the lead district proper; and whatever may be said in favor, or otherwise, cf the lower magnesian there, can have no more bearing on the lower magnesian underlying the mines of the lead district, than the very rich mines of Missouri found in the same formation. The upper maugnesian, at this distance from the known boundary lines of the lead- district, has in no instance shown more favorable conditions than what are presented there at Kickapoo. But whatever may be the conditions presented I y this forn aticn at that distance from the mineral beits of'he lend district, whether favorable or otherwise, they furnish no rule by which we can determine what it may be in connection with the physical conditions of the lead district, that has rendered the upper magnesian so productive. The other place visited by the writer, where mining had been done in the lower magnesia.., and in fact the only place he had vis 40. ited personally, uas Olcking's diggings, near Franklin. These digging are situated on the extreme north side of the lead district, and a little to the north of the belt of mineral land in town six, the last belt of the lead district in that direction, but near enough, por. haps, to comne so ewhat at least under the influence of the physical forces of that belt. "'On visiting this locality in 1859," says the writer, page 412, "I found only one person at work there, from whom a very dismal account of the prospect of mining in the lower magnesian was obtained. e-Ie had sunk a shaft twenty-five feet deep, from which he had raised about ten pounds of ore; but I was unable to detect any sign of crevice or opening in the excavation; and as no other was accessible, my impressions were necessarily very unfavorable in regard to the prospects of mining i': this'formation, especially after listening to the vehement objurgations of this solitary miner against his own stupiditv in continuing to prospect in so barren a rock." This is the only place rear the lead district visited, by the writer, where any information could be obtained in reference to the lower magnesian; a,nd all the evidence by which this formation was condemned was obtained from this little hole about twenty-five feet deep, sunk inl the rock. as the writer says, without any signs of crevice or opening. Who, with the first elements of the knowledge of mining, would expect to find ore in such a place? It would be in, conflict with every known mode of deposit in the lead district, and with the laws governing mineral veins everywhere. I do not wonder at the man's upbraiding himself for his stupidity in spending his time looking for ore in rocks where there was no sign of a fissure or opening, I only wonder that such at mar had sense enough to know that' he P-as st.apid. If the truth was known, I think we should find the fellowing to be the facts: The man was working on the land without learve-as was too often the case in those days -and supposing the professor to be the landowner, or his agent, gave him this dismal account to prevent being questioned about how much rent he owed. Dr. Percival, who visited this place so.e years before, when the diggings were open and working, gives a very different account of this deposit of ore in the lower magnesian. He says that three successive openings occur there, one 8 cr 10 feet below the sandstone, another just above the harder middle bed, and the third.below the bottom of the ravine, in that bed, and at the depth cf seventy feet in the lower magnesian. He further adds: "The openings appeared partly narrow anrd vertical, partly wide and flat, with appearances of decomposit on and stain in the rock, deposits of clay and ochre, and arrangement of mineral, similar to those in the upper magnesian, (galena limestone ) The mineral in these openings generally appeared in more or less detached masses (chunk mineral) often very large, weighing more than 100 Ibs, a few, more than 500 lbs. After examining this locality, I could not doubt that the lower magnesian is a good mineral bearing rock." 41 These are the statements of a man who saw and studied the deposit, and the mode of deposit, and the relation of the deposit to the kind of rock in which it was found; a man fully competent to judge. I \d onId call attention here to another error, that enters into the belief bf the inexperienced, and sometimes into the teachings of scientific men, namely, that mineral bearing rock or strata should always be productive at the sureace; and unless it is, it should be condmuned as barren. Such views occupy a very Irominent place in the last report of the lead district. If the physical forces and physical conditions necessary to kroduce mineral veins, and ore deposits, acted on the strata from above, it would be reasonable to expect large deposits of ore on the surface, or in depression on the surface, or in cracks, and crevices extending downward into the rock from the surface, especially if we must look to the sea for our metallic solutions, and to veget able and animal remains, as the precipitating agents. But when we take into consideration the fact, or what is now acknowledged to be a fact, by every intelligeDt, practical man, and by every scieitific man that has any practical knowledge of mining, that the forces of the mincral kingdo b act upon it from below, thun the fallacy of such, views becomes apparent. It is true we do sometimes find rich deposits of ore at, or near the surface.:But the question is, were they formed there, or were they form.d a' great depths in the rock, and subsequently brought to the surface, by the surface being brought down to them by denudation. I question very much if we can find an important and productive mineral district on the face of the earth, but that above it hundreds, and in some cases thousands of feet of rock have been removed by denundation, since the deposit was 1xrmed. Let us apply these views to our own lead district. According to the Statement of Prof. Whitney in our last report page 125, not less than 35U or 400 feet of vertical thickness of the strata of the lead district has been removed by denudation. Let us take our stand for a short time on the original surface of the lead district, say 350 feet above the present surface, near which w large portion of the ore in the lead district has been found. We are now separated from the upper magnesian limestone by at least 200 feet of what. is called the Hudson river group, and the Niagara limestone. Nothir.g more could be known then of the upper magnesian lime. stone from the original surface of the lead district than can be known now of the lower magnesian from the present surface. The upper magnesiun was then, as the lower is now, hid beneath two or three hundred feet of a different class of rock. Suppose, however, that examinations were made at that time beyond the limits of the present lead district, where the upper magnesian would become the surface reck, that is, where it could be seen without any exeava 42 tions being made, and finding it barren, as we know it is to-day, where it can be seen, it was pronounced to be barren rock, and from what was seen of it there, it was pronounced to be barren rock everywhere else in the State, That is to say, be ause productive mineral veins, or ore deposits, were not found on the surface, exposed:.y natural age. cies, where the:ock might be seen exposed by the most casual observer, it must therefore of necessity be a barren rock; what would we think of the judgment of such parties to-day, when denudation has removed the overlying strata, and brought to our view in the upper m: gnesian ore deposits at which the world has been astonished? And yet these are the very views, and evidences by which the lower mnagnesian is condemne i to-day, and for no better reasons than those assigned above. There is not a place in the lead district where the lower magnesiun is ecen, or can be seen (without deep mining) in connection with the physical conditions that have rendered the upper magnesian so productive. And to say it is a barren rock beneath the mines of the lead dis trict, from what we can see of it out of the lead district, is tho height of folly. Such views are unworthy either of practical or scientific men. Now while I would guard against these errors held by certain parties in their views of mineral strata, I would nevertheless call especial attention to the fact, that certain kinds Of rock in the came strata, or rocks that have undergone certain changes by metamorphic action, do present to the causes producing mineral veins, and ore deposits, more favorable conditions for the precipitation of metallic solutions than others, and that we do in our mining operations find our richest deposi's in rocks of this character, while rocks of a different character, traversed by the same fissures are barren of ores. Dolomites, or magnesian limestone, are classed with those rocks that present these conditions And no matter, whether they are the upper or the lbwer, in the strata, whether they are found in the United States, or in Europe, if they are traversed by fissure, through which mineral solutions are passing especially lead, or zinc, they are almost certain to contain deposits of the ores of these metals. Thies favorable conditions presented by the limestone, especially by the magnesian limestone, for the deposits of lead, and zinc ores, have been noticed by mining men everywhere, especially in Europe; and by the largest portion of them, it is supposed to consist in the readiness with which it yields to the solvents traversing the fissures, and'the favorable reaction of these rocks on the metals present in the solution. As evidences of this, our attention is called to the fact, that it is only lead and zinc that is found in any abundance in this rock, and that the lead is never rich in silver. Is it, -asked a noted writer,-because a very small percentage of other metals were present in the solution, or because these rocks reacted less on them than on the lead and zinc? 43 VWe notice in the magnesian limestones of the lead district, where they are exposed to atmospheric agencies, that there is a tendency to weather, or decompose irregularly, as though some portions of it, would yield more readily to solvents than others. We notice also, in our mines, that our crevice openings are confined pretty much to such places; and our largest and richest deposits of ore are found in what is called tumbling openings, that is where the rock has been decomposed on a large scale, and the- detached portions of the rock remaining mixed up with the decomposed material.. In such places it looks as though the carbo~ate of lime, and the carbonate ot magnesia were dissolved, and the ores of lead and zinc deposited in their places. It is in all probability this feature of the limestone which gives to these openings their irregular, peckety nature. In reference to this lower magnesian limestone that underlies the mines in the lead district, and that has not yet been reached by them, the question is often asked, isit a mineral bearing rock, or not? To this I would reply: A direct answer to this question cannot be given in the present stage of our milling operations, from thb fact, as before stated, it has not been reached in any of our mines, and has been prospected in only in two or three places near the lead district. For this reason then, the relation of our mineral veins to the lower magnesian, and other strata below where the mines are being worked, must be established, if established at all, by other evidences than what is presented by actual observation. I have visited several places to the north of the lead district, where the lower magnep an becomes the surface rock, and where lead ore in small quantities has been found. At Orion, in Richland county, where a small range of fissures crosses the north, and south axis near the fourth principal meridian, very fise specimens of lead ore are found. At Rio also, in Columbia county, on the eastern extension of the Baraboo range of hills, very good specimens of lead cre are found in the lower portion of the lower magnesian limestone, which for quality, and fcrm of crystallization are equal to anything we find in the lead district proper. It is true these deposits in the lower magnesirn, out of the lead district, do not compare with the very heavy deposits of ore in the upper magnesian in the lead district, and it would be unjust to draw a comparison between them, from the fact, that the same evidences of the action of physical forces from beneath are not found. Yet when compared with similar places in the upper magnesian out of the lead distri ts, under similar conditions, the lead bearing qualities of the lower magnesian ere equally apparent. Specimens of the rock and ore taken from these places in the lower magnesian may be found among the specimens of the survey in the Academy of Science at Madison. 44 MINERAL VEINS. No class of natural phenomena of equal importance has received less attention from scientific men than that of mineral veins. Not because it is more refractory, or yields with stubbornness to investiga.tion, but because it is a class of. phenomena inaccessible to that class of reen except on special occasions and for special purposes. A knowledge of mineral veins and tie laws governing their formation, filling and development, cannot be obtained from hand specimens; nor can it be taught successfully on a blackboard, cr from text books Such information is obtained only by long continued practical observation. It is true that this question has been taken up by scientific men, and introduced into scientific schools, and theories have been formed and given to practical men as guides to direct them in their work, and to explain those natural phenomena with which they come in contact. But such theories, as a general thing, have been of but little use to the minor, the principles they inculcate seem to have but little adaptation to the phenomena they are designed to explain, hence the miner has thrown them aside, trusting rather to his own judgment. No branch of industry is more'intimately connected with, and certainly no branch of industry is more dependent on a knowledge of natural phenomena, than mining. And it is a mistaken idea that practical men do not study this phenomena, and from it formn theories to guide them in their work. They are trained in this work almost from infancy, and their faculties, or powers of observation are developed to such a degree, that they recognize instinctively the features of good mineral-bearing strata; or of fissures that are likely to be productive. Hence their theories are not so much of form, as they are of instinct, formed by long continued observation of c very-day life. The practical miner may not be able to tell us why these are the features of good mineral-bearing strata, or why these fissures are likely to be productive; but in his judgment they are, and this judgment well matured, like instinct, is in most cases infallible. Between the theories formed by scientific men, in scientific schools, (and as is often the case, from imperfect data, or a narrow range of observation,) and the theories formed from the experience of ages, and the closest observation of practical men, there has been, and still is, a conflict. And because of this confli t, and want of adaptation in so-called scientific principles to explain natural phenomena, there hMs arisen also a feeling of hostility among practical men generally to all scientific teaching on these questions. Nothing, perhaps, would have a greater tendency to promote mining interests throughout the world, than for practical and scientific men to meet on common grounds, where their conflicting views can be reconciled, and where each can take their appropriate work in solving the problem. That there are scientific principles underlying 45 the theories of practical men there can be no doubt, and if these principles were explained to them, it would be an incalculable bonefEt. If bcience, then, would content herself with explaining these principles of natural phenomena, leaving the application of them to practical men, the practical and scientific departments of mining might be harmonized and worked together for one common end; that is the development of the mineral resources of the earth. It was mjr misfortune to be sent to the mines to earn my living, when not quite ten years of age. I had to commence with the simplest forms of mining and work my way through a regular course of practical training for a miner's occupation and a miner's life. With but very little edueatiorn, and no prospect of positions of honor or profit in this life, but what was found in connection with this branch of industry, I resolved to master the art of mining, and gain-if possible some of the rewards and positions of honor that this branch cf industry held out. Inheriting the native instincts, and receiving as a legacy, the experience of a lmng line of ancestry, whose origin dwindles out, and is lost in the history of the C(ornish mines, I entered upon this work Laying hold of anything that would aid me. It was here I first came in contact with the conflict between scientific and practical theories. Prejudiced by early education, and associations, against the the'ries of scientific men, I shunned for some time all scientific books, and yielded slowly to the teachings of nature, not knowing then that science was nature properly interpreted. In the progress of this practical training, like every other miner, I was brought in contract-with the richest phenomena of the natural world. The harmony and order that pervaded these phenomena, and their conformity to some general principles unknown to practical men, attracted my attention, and called forth my aimiration. From this time I became an ardent admirer of nature, and aclose observer of her phenomena. i commenced also to collect simple facts, and phenomena, and to arrange them so that they would explain other things not so simple. In this course I was led on from one class of phenomena to another, gain ing all the time a rich experience, and adding very much to my stock of practical knowledge. Before I was aware of the fact, I was forming theories, not altogether from practical observation, and mining experience, but from'j eductions made:rom certain classes of facts, and from principles that I found underlying certain classes of natural phenomena. In pursuing -his course, I found, that in all natural phenomena, there is a chain of facts, that leads unerringly back, link by link, through the unfoldings of nature. to some general laws, that under lie them as their cause. And that it is the privilege of the practical miner, without a classical or scientiic education to follow this unerring light, until he has become acquainted with these laws, and consequently is able to explain those phenomena for himself. From 46 this stand-point made of home-spun material, partly practical, and partly scientific, let us take a view of mineral veins, and ore deposits, in general, and those of our own lead distri t in particular. If from the same stand point we could see all the mineral veins, and ore deposits opened in the crust of the earth, two things would especially attract our attention. In the first place we should notice that there is a general unity that characterizes the deposits of ore in every part of the wjIld, as though they were th~ results of the same general laws. In the next place we should notice that there is a general diversity; two places can hardly he found that are not distia-.:guished from each other by lcal differnces. This may seem strange to one unacquainted with mineral strata, but it is true, and its explanation can be found only in the following cons.derations. Fissures, and mineral veins, are not one and the same thing. Fissures are openings, or fractures in the rock, in which fractures or openings, mireral veinis or ore deposits may or may not be found. Hence we find that fissures and mineral veins are two different things, formed at different per',ds, by different forces, or physical conditions, and should be considered as two separate and distinct classes of phenomena. In thin light let us examine them separately. Fissures, (in connection with which mineral veins or ore deposi ts are found,) are always found along lines of physical disturbance in the earth's crust, and are, beyond all doubt, the consequences of mechanical causes, or the results of mechanical forces acting from below. Every man -wko has made the subject of mineral veins his study, will adrnit this to be true But the character of fissures is made to depend on various causes, hence their diversity of form, which gives the diversity of form to mineral veine and ore deposits. In examining the causes, of which fissures are tshe consequences, we have to notice, not only the intensity of the elevating force acting beneath a given line of strata, but the resistance opposed to this force by the cohesive power of the rocks, or material thus acted upon. If for instance the mass acted upon, should be a homogeneous mass of crystalline matter, whose cohesive power varied but little, and this mechanical force steadily increased till the tension became sufficient to overcome the cohesive power of the mass, a rupture would be the consequence, and fissures would be produced that would extend evenly through the entire mass. If on the other hand,the strata is a heterogeneous mass,composed of beds of rock, of uneven thickness, and cohesive force, such as alternate beds of friable eandstone and compact limestone, as is very often the case, the results would be very different. If this mechanical or elevatory force, should be acting upon those beds of rock, through the medium of some fluid, such as heated water, or elastic:vapor, it would meet with but little resistance in the sandstone, while the compact limestone would oppose it with considerable cohesive force, and would not yield until the tension became 47, sufficient to produce a fracture in the limestcne which would be, of course, along the line of the greatest tension. Toe effect, then, of such forces upon strata composed of such like beds of rock, would necessarily present itself to us in a variety of forms. It might pass through. friable sandstone without leaving the sign of a fissure, whi'e the same force opposed by the cohesion of the limestone, would become an elevating force, gently lifting the thin beds of rock, (in some pl lees pas ing between them) while seeking to force a passage through. In this way the fissures along a line or physical disturbance, would vary in form, and character, in proportion to the nature and degree of resistance opposed to this mechanical force in its passage through the different beds. Another result of mechanical force acting upon such strata through a fluid medium, especially if it should be rising from fissures in a lower and older formation, would be as followe: Coming in contact with a bed of friable sandstone resting upon it, this fluid medium, (whether water, or vapor,) would`b scattered through a lage portion of the rock, reaching the beds of limestone above in a different condition, In such eases, instead of a single fissure over the centre of force, wa should find groups of fissures scattered over a wide surface. Such phenomena are common in mineral strata. Mechanical forces, also, differ in their character and mode of operation, ecnsequently fissure_ that are produced by them are different. Ience to obltain a correct knowledge of the different forms, and systems of fissures, it is important that we study these forces, and their results itr their separate forms. An illustration, perhaps, will place this subject in clearer light, than any language that I can command. Suppose the Blue M.ounds, the Platte iMounds, Sinsinnewa Mounds, and oth r elevations of land in the lead district, were elevations of granite, or any other plutonic rocks, that were elevated subsequent to the formation of the strata of that district. The result would be extensive displacement of tile prior-formed rocks; it could not be otherwise. Another result wouldbe, the rocks into the midst of which this igneous, or melted miass had been protruded, if not crystalline before, wouild now, by heat rising from this cooling material become metamorphic rock, and to a -reat extent, if not fully homogen ous and crystalline. Our sandstone would be changed into quartzite, or' quartz ro-k. Our magnesian limestoacs into serpentine, or some other form of metamorphic rock.'t The fissures, faults and dislocations in the rock, produced by this plutonic action, (or form of mechanical force), would necessarily cut through the strata vertically, or nearly so, and to a great depth, thus permitting the rise of metalliferous vapor or fluids which may be generated in, and by this heated mass below. Here we see distinctly the relation between this form of mechanical force acting through melted matter as a medium, and the peculiar phenomena presented in the strata in which, and through which it has acted 48 The protuding igneous masses, the metamorphic action, the displace. ment of prior-formed strata, the faults, dislocations and fissures in the disturbed and altered rocks, are the known results of this form of force, and. it cannot well be spent without producing such results. But suppose again that this elevation of igneous matter had taken place beneath the waters of the ocean, where stratified rocks would commence to form over thit igneous mass, and over'these faults and dislocations in the earth's crust, that were exterding down and communicating with the heated region below, and through which metalliferousvapors and fluids were rising, and would continue to rise, what woild be the results? In the first p'ae there would be a change or transformation of mechanical force; it would no longer be plutonic, that is, acting through the melted matter as a medium, but hydro plutonic, that is, acting through water as a medium.:In the next place, a change in the form of the force, would be followed by a change in the form of its results. Hienee between fissures produced in rocks by plutonic action, anl those produced by hydro-plutonie action, th, re would be a line of distinction, and we often find them'presented to us in nature, as two elasees of fissures. A moments reflection on the conditions bringing about this change in the forms of force, snd their result,s. will enable us better to understand the modifications, and diversity in the forms of the.two classes of fissures. These masses of melted matter, forced up through prior-formed rocks beneath the waters of the sea, and over which stratified rocks had commenced to form, will part with their heat slowly. Radiation, nevertheless will take place, and continue'till these igneous masses are brought down to the temperature of the strata into which they have been protruded. One of the effects of radiation here, would be to change slowly the character of those prior-forraed aqueous rocks. lieta:uorphic action would be induced, and the result of this form of force would be the transformation of these rocks, into rocks of a metamorphic character. Beautiful, (and I had almost said living) examples of such conditions, are found in the strata of the Cornish mines. Several large masses of igneous, or melted matter, (now in the form of granite) have been thrust up through what was once fine sediment, or sedimentary material of' aqueous origin. These sedimentary, or stratified rocks, are now transformed (by the action of heat radiating fromu these igneous masses in their midst) into various forms of slate rock, or as the miners call it there, kellas. The degrees of transformation, even, can be traced from the points of contact, away for considerable distance into the slate rock. In the gradual decline of the temperature of these igneous masses, there would eome a time when they would fail to transmit a sufficient amount ofI heat to maintain this force of mretamorphic action in the surrounding rocks, The heat which at first must have been generally diffused through the adjacent rocks, from the entire igneous mass, will now be confined mostly to these lines of fracture, and dislocation, extending down. to, and into these masses, and through them, opening communication with the heated interior. At this point we may look for another transformation of force, for below the point of temperature at which metamorphic action ceases, water will find ius way into these fractures and dislocations by its own force of gravity, and yielding more readily to the action of heat than rock or solid matter, it becomes the medium through which radiant heat and mechanical force act. At first water may be transformed into elastic vapor, and wrought up to its highest tension. In this form its mechanical powers under pressurebecome such as will defy all calculation. In the wafting of a steamboat, in the velocity of a train of cars, or in the motion of huge machinery, we see only glimpses of its power. It will not be very strange if at some future period, it should be depoSn1d srlq ooaoj loo!untqamO jo muaoj sql 1q plo aqi oq pesualsuom an important part in earthquake phenomena, and in lifting islands, and even continents from the'ocean's bed. From the highest point of tension up to which water in the form of vapor can be wrought by heat, down to mere thermal waters that bubble up through fissures in the rock, the mechanical and chemical powers of water under the influence of heat, are beyond anything we know of, or even can conceive of, in connection with the formations and transformations of matter and force as presented in the crust. of the earth. Stratified rocks, then, forming over these fractures and dislocations will be acted upon only by this form ofmcchanical force, and the fissures produced in these rocks, over these lines of mechanical disturbance, will assume forms conforming to the action and reaction of this force with the force of cohesion that will oppose it in the heterogeneous mass of rock above. To generate this form of force, and to keep it in action through vast periods of time, it is not always necessary that we should have as a source of heat, a mass of cooling granite or trap. Stratified rocks formed over similar fractures in older formations, such as the azoic, would be subject to similar conditiors, -and preeent similar phenomena. I have already stated that fissures produced by the action of these fcrces,are suffciently distinct to be divided into two classes of fissures. I have also called one form of force plutonic, the other bhydro-plu. tonic. These terms may not be such as a scientific man would use, but they will answer my purpose very well. I want to use them only as a line of distinction between these forces, and their results, or rather between these formi of forces and their results, for they are only modified forms of the same force; one being heat acting in, and through igneous matter, as a medium; the other, heat acting in and through wuter, as a medium. 4 50 Taking this as a basis of classifications we shall have as a natural consequence, fissures that are produced by plutonic action, and fissures that are produced.by hydro-plutonic action. And following it still farther, we shall have'mineral veins and ore deposits, peculiar to the one class of fissures, and mineral veins, and ore depGsits peculiar to the other class of fissures. This classification would result in (what is so clearly defined in the experience of every practical miner) two systems of mineral veins or mineral strata. In connection with these facts would come the question of the relative value, or productiveness of these two systems, a question in which all that are connected with mining are interested. Now while it is evident to every practical man of wide experience that there is this diversity in the forms of mineral veins, resulting froln a diversity in the forms of fissures in which they are found; which also result from a difference in the texture, cohesive and crystalline conditions of the strata acted upon by two or more forms of mechanical force, yet it is also evident that these forms of force, are only modifications of one and the same force, and that force, the ultimate source of all physical conditions connected with the mineral kingdom, namely, internal heat. Upon no other hypothesis can we successfully unravel the complicated processes of mineral formations. I have dwelt longer upon this question of fissures than would be necessary under ordinary circumstances, but I wish to bring this question out here, for the following reason. There is a tendency on the part of a certain class of geological observers of mineral strata, (especoally in this country), to regard only as mineral veins, such as are found in fissures of undoubted plutonic origin, regarding all other forms of mineral, or ore deposits, as mere surface deposits, produced by atmospheric agencies, or some other physical conditions acting on the surface, consequ6ntly limited in their vertical range to a very few feet. Sunh views are not only detrimental to all mining interests, and the development of our mineral resources, but in direct conflict with the phenomena of mineral strata generally. Mineral veins, ([have stated before) and the fis:ures in which they are found, are two different things,. formed at different times, under different physical conditions. Practically considered, mineral veins are simply the filling up of fissurcs, of all kinds, with material brought into them from soine where, and by some process. This material differs widely from the rocks in which the fissures are found, hence we may safely call it foreign material. But whether this material has been brought into these fissures by physical conditions, act. ing from above, or by physical conditions acting from below, is the question that has divided the opinions of scientific men. As long ago as 1546 theories were formed to explain the filling of fissures with mineral matter; and almost as long ago as that, scientific mon were divided as to whether it was from above or below. In the seventeenth century, Werner's theory of descension was introduced to explain the: formation and filling of mineral veins from above. Thevein-stuff (said Warner) arose from a wet precipitate which filled them from above; that is, from a wete and mostly chemical,qlution, which covered the region where the fissures existed, and at the same time filled the open fissures. Such theories were introduced into scientific minibg schools, and have tinged the belief of quite a number of professors, both in Europe and America, Lut they have never been adopted ty practical men, they having no adaptation whatever to the phenomena of mineral veins. And it is a great satisfaction to know that such theories have lost what little influence they may have had in these schools. For even there they are now, not only obsolete, but ranked among the follies of the past. The royal school of mines at Freiberg, Saxony, in which Werner wasa professor, and where he used all. the influences and appliances at his command to develope his theory, has thrown it aside as unsound and worthless. The present professor in the same royal school says: "Neither the; theory of contemporaneous formation. nor that of descension has any upholder since Werner; unless Kuhn in his'Handbuch der Geognosie' be considered as such," although he only endeavored, as a faithful pupil of Werner, to defend his teachings. We may not be able to explain fully where this material filling the fissures came from, or by what process it was brought into them and formed into veins or lodes; but we have the following facts, that will certainly afford some light on this question: A mineral vein is positively an aggregation of mineral matter in a fissure, no matter what its angle of inclination, or the character of the rock it traverses. This material is highly crystalline, and in nany cases beautifully crystallized. And most of these forms of crystallization we know must be the result of chemical deposition from water. Not orily the forms themselves, but everything around them forbids the supposition of crystallization from fusion, and even what we cannot prove to be chemical depositions from water, offers no reason why it may not be so. I have carefully noticed: the contents of mineral veins for miany years, and in almost every class of rock and form of fissure, but have not yet seen a vein, the fornmation of which could be explained by plutonic or igneous action. Fissures may be, and no doubt are in many cases, the result of s ch conditions, but the filling of these fissures with mineral matter, as a vein, I think never is. The nature of this material, and its arrangement in the fissure, shows beyond doubt that it is the work of chemical forces, and that too of chemical forces acting through water as a medium. Perhaps it would be putting the question in a simpler form, and be equally near the truth, if I should say that mineral veins are the results of the mechanicIl and chemical powers of water under the influence of heat. I have already stated the fact that water, when heated up to a certain point, and under great pressure, generates a mechanical force of almost unlimited powers. With this fact we are familiar. Let me here notice another fact, with which we are also familiar. Water, when heated, becomes a strong solvent, and stimulates, to a high degree, chemical activity. Aided by other solvents which it holds in solution, there is hardly any solid body but will yield to its power. At a high temperature, under great pressure, it is capable of dissolving, and holding in solution, a vast amount of material, whether that material is brought under its influence, either in the shape of solid rock, or gaseous emanations. In this heated'water, saturated with mineral matter, we find als )another class of.iehbemical forces, ready, at the lowering of the temperature, to aid, -by their natural affinities and reactions, the work of molding this'material into solid and symmetrical forms, such as we find in the;filling of mineral fissures. And again, let me notice one other fact. The point of temperature in depth, at which water is converted into steam (and consequently into mechanical force), is the point, or about the point of temperature, at which gases and fluids meet. At this point gaseous emanations, and metallic sublimations, rising,through fissures from the heated interior, must necessarily be condensed in water, and driven up by mechanical force through fissures ~in the rock above, f o be deposited along their sides as aggregations -of fi-ineral matter, where the temperature and other conditions will -adin-it of it. 1 think there canll be but little doubt; if any, that the mechanical *and chemical powers of water, together with the forces which they generate under the influence of the varying degrees of heat, form the essential elements in the physical conditions necessary to the [,roduction of mineral veins and ore deposits. Nor is it the action of mechanicall and chemical forces alone, but the beautiful system of foeces produced by the actioi. and reaction of these forces upon each other, that has given to us the harmony and order that- pervades mineral strata and mineral veins everywhere. The universal phenomena of mineral strata points to such con. ditions, and harmonizes with such an origin. Nor do I know of a single law of nature with which it conflicts. Every practical miner knows very well that in the neighborhood of productive mineral veins, even the same kind of rock presents different appearances, as though in certain places it had undergone a change from its original condition, while in others it remained unaltered. This altered condition of the rock runs in given lines, or zones, conforming fully to some directive law. It appears also to have been exposed to peculiar physical conditions subsequent to its formation, as though there was an unequal distribution of heat or vapor, or solvents of some kind producing a marked difference in the structure, while the chtmnical-composition of the mass remained the same. This. altered rock presents more favorable conditions for fissures than the unaltered. It looks almost as if it had undergone a special preparation for this purpose, The whole mass seems to be traversed in all directions with fissures, filling it with ramifications not unlike veins in an animal, and like them circumscribed by natural law. They are of all sizes, from a large dike down to a small threadlike seam, too small to be seen hy the naked eye, but in a fine grained rock, with a magnifying power may be seen traversing the rock with all the regularity of larger ones. And what is very strange, we have in this miniature form of fissures and veins, all the systen,'and regularity, together with the same relations, actions ant reaction upon each other that we find in the larger fissures, and veins that constitute our mineral strata. I obtained, some time ago, a beautiful sipecimen of this miniature form of mineral veins, in a small.lab of limestone, that represents very forcibly this feature of mineral strata. This slab of limestone is deposited~ with the mineral specimens of tt c lead district, and can be seen at the State Agricultural Rooms, Madison. In this altered, or prepared rock, the larger fissures in which productive mineral veins are found, occupy a central position, into which these minor fissures, or seams seem to fall, or firom which -they seem to diverge. That there is a relation between these minor fissures, and mineral veins proper, all intelligent miners agree, but what that relation is, is not so clear. It is tfle opinion of a certain class, that these small fissures, or seams colltribute in soEme way to the productiveness of the'.vecin, hence they are called feeders. When a miner seces those little feed~ ers, or as they are' sometimes called, droppers, beginning to traverse. the stranta though which he is drifting, especially if they contain. ore, he feels that he is almost certain of a productive vein. It was usual for us in our English mines to speak of 5 lode, (01r vein) and ics branches, as though these little fissures were thrown off from the lode like branches from the trunk of a tree. This view would lead us to suppose that the vein, (or lode) was the source of the branches, instead of the branches being the feeders of the vein. Thiis idea, perhaps, has grown out of the fact, that, these little branches, or seams, are small, but well defined near the vein, and often filled witl material similar to the vein itself, but as they recede from the vein they grow, less distinct,,and become lost in the joints, and cleavage of the rocks. Tlfese are some of the features of mineral str'ata as they are seexi practically. They, are not local but general phenomena; -not confined to,one elass of rock, nor to one class of fissures, nor to one class of mineral veirs, but they are the results of general laws that underlie them all. They are also the practical miners texst-ook, in, which he studies, and from wbich he teaches his children the prine. pies of practical mining. And it is from a knowledge of those principles that his judgment is formtd, a judgment sometimes so matured as to become almost unerring in the selection of mineral ground. But of the laws underlying these phenomena as their cause, he is ignorant. Not ignorant of their existence, Jor he is surrounded with their phenomena, and guided in his works by their phenomenal teachings, but ignorant of their nature, and their mode of operation. Now if science can come forward with the laws governing mechan. ical and chemical disturbance in the earth's crust; the laws governing the direction of those lines within which these forces work; the laws governing the relation and correlation of forces combined to form this beautiful system of forces, the harmony and order of which is given in this beautiful system of fissures- so apparent in mineral strata, then this practical knowledge of mining may be placed upon a scientific basis, and the cause, or causes of mineral formations be as logically and as safely deduced from this phenomenal data, as the existence of Neptune was deduced from the disturbances of Uranas. And if with this, we could banish'from our mining creeds the ele. ments of chance and caprice, and admit in their place the teachings of natural law, I can see no reason why the time may not come, when from this combined knowledge of practical and scientific men, we may not be able to point with as much accuracy to those productive places in the earth's crust, as the astronomer now points to' the return of a comet in the heavens, or an approaching eclipse of the sun, for both are the results of natural laws, and these laws are within the reach of man. Now -will this time be long delayed, if only scientific men would become more practical, anld practical men more scientific. But let us turn now to the mineral veins and ore deposits of our own lead district. In entering upon the consideration of the mineral veins and ore deposits of the lead district, we do well to bear in mind the phenomena of the district as a whole, and even its connection with phenomena outside of it, for the general laws underlying mineral formations as their cause, and especially mineral distr:cts of large extent, can never be explained by local observations of limited extent. On the character of the rocls in this district I need say but little; this, with their geological relations, is fully described in the report of 1862. I will just state; however, for the benefit of th'oe who have not Eeen that report, that the strata of the lead district, so far as it is exposed by mining, are: 1st. A bed of limestone, known locally as the galena limestone, but chemically is a dolomite, cr magnesian limestone. It is about 250 or 300 feet thick, and o7erlies a bed of compact fossiliferous limestone, known'locally as' the blue limestone, but in its geological- order as the trenton limestone. These strata are of the lower silurian age, but are comparatively undisturbed by either plutQnic or metamorphic action. That is, there are no elevations of granite, or trap, or any other igneous rocks protruding through these strata. ,55 The fissures traversing these strata are not like those in which we find, what is called true fissure veins, such as are found in crystalline rocks of plutonic or metamorphic origin, but fissures peculiar to this class of strata, as is now demonstrated in similar lead and zinc districts found in different parts of the world, and belong to that class of fissures I have denominated hydro-plutonic. These fissures traversing the galena limestone are usually verti-,cal, or nearly so. The ore is sometimes found filling the fissure where it is small, with little or no other matrix than the limestone,walls, against which it is formed. In this condition it forms a sheet of ore (as the miners call it) from 1 to 20 inches thick enclosed firmly in the rock. Where the fissure is wider, and its sides show,evidence of decomposition, the ore is usually found in a clayey matrix lined with ochre. The larger deposits, however, are found where the rocks between two or more fissures have been decomposed, and ar c called by the miners "crevice openings." This decomposition usually takes place beneath a harder portion of the rock, as though greater resistance had been offered here to mechanical forces acting from below, and a gentle lifting of the strata had taken place along the line of the fissures. As an evidence of this, we always find beneath this cap-rock (as it is called) a seam extending from the sides of the opening horizontally, directly beneath the cap-rock, and it is where this horizontal seam intersects the vertical fissures that the decomposition takes place, and the ore is deposited. As a consequence of this, wefind these openings, not only, along the same range of fissures, but along the same horizontal plane. There is a fact here worthy of a moment's reflection, and its teachings should be heeded. These de. posits of ore are always found beneath this cap-rock, and never above it. Query: WTas it introduced from above, or below? In onenings like this, where the rock has been decomposed between two or more fissures running parallel to each other, we find not only clay and sandy material, the results of decomposition, but often large pieces of partially decomposed rock, with every appearance of having been attacked by strong solvents. These openings vary in size, and are found from five to forty feet wide, and from ten to fifty deep, continuing from one hundred to several hundred feet in length, and yield often from one to five million pounds of ore. The material in these openings is not a disorderly, incoherent mass, bus is arranged mechanically and chemically under some general law peculiar to this form of deposit. The finer, softer materia such as clay and ochre, is arranged along certain lines, while the carbonate of lime dissolved out of these decomposed rocks, is re-deposited in the form of calcareous "spar to form with the finer part of this clay and ochre a matrix in which these ores are deposited. In such openings, it looks as though the medium in which and through which, these solvents, or dissolving agencies acted, furnished also the solutions from'which these ores were formed; a though nature first prepared the place, and then deposited her treasure. In the early history of our mines it was thought that where these openings closed in depth, was the extent in vertical range of our ore deposits, but subsequent mining has shown that they succeed each other in the downward course of the fissures, and now not only the second, but the third, and in some places the fourth opening in depth has been discovered, and: the fissures continue their downward course as before. Inasmuch as this irregular form of fissrce, and consecquently irregular form of ore deposit has been th'oe cause of a wholesale and sweeping condemnation of this lead district, that has discouraged all enterprise in mining,-one of our most important branches of industry-it may be well for us to notice here, the relation that this form of fissure, and form of ore deposit bears to similar ore districts of known reputation that have passed through alternate periods of poverty and richness for ages, and yet supplied the commercial demands of the world. Von Cotta, in his able work on ore deposits, has arranged those districts for us, with the following description "Irregularly formed, more rarely vein-like, in part very massive aggregations of galena, blende, calamine, and smithsonite, occur in limestones and dolomites of very dissimilar age, in upper Silesia, in Westphalia and Belgium, at Weslock in Baden, in the Corinthean Alps, near Anduze in France, in the Spanish province of Santander, as well as in the states of Wisconsin, Illinois, Iowa' and Missouri; they are all of a similar; but by no means contemporaneous, origin. Great districts must have been penetrated by metalliferous solutions; from which the precipitation of the above ores took place, for the greater part only in dolomite or limestone, frequently at their expense." "To be more clear, the solution traversed the considerably fissured rock, and this reacted in such a way on it that carbonate of lime and magnesia were dissolved, the ores being deposited in their place. * * * "it is altogether inadmissible to suppose that the deposition of the ores occurred, in these cases, contemporaneously with those of the limestone or dolomite; the whole manner in which the ore is distributed is opposed to this.' In the table of localities of this class of ore districts, furnished by the writer, we find some of the most productive lead and zinc mines of Europe, such as the D)erbyshire, and Cumberland in England, those of Aix la-Chapelle, Upper Silesia, with those of France and Spain. In these forms of deposit, no feature is so prominent, as that which points to a medium through which powerful solvents worked out places for their ores by widening the fissures in certain places, and leaving them almost closed in others. Heated water. with its chemical forces, urged through these strata by mechanical force, is the only mediumswe can conceive of adequate to this work. And no doubt one reason why these forms of fissures and ore deposits are found oftener in dolomite, or magnesian limestones than in other rocks, is its peculiar adaption to this process.of mineral formation. That Von Cotta entertained similar views, is evident from his remarks an the different forms of ore deposits, which are an follows: {" Thus the formation of lodes shows itself to be not only possibly, but also probably, very manifold; and appears to have always stood in some connection with neighboring, and often shortly before occurring eruptions of igneous rocks. The local re-action of the igneons fluid interior of the earth created fissures, forced igneousfluid masses into many of the same, caused gaseous emanations and sublimations in others; and in addition, during long periods of time, impelled the circulation of heated water, which acted, dissolving at one point, and again depositing the dissolved substances at another, dissolving new ores in their stead. The whole process is thus not confined to any particular geological period, or any particular locality; but recurs at all times, either in the same or new regions, at the point where a re-action of the interior of the earth has taken place." With these views obtained from important ore districts, similar in their oriagin to our own, it becomes us to scrutinize closely the phenomena of our fissures in their downward course, ard receive very cautiously, and with a certain amount of distrust, any statement or statements made in reference to their closingin depth, since in these older districts actual tests have been made, from which we may draw important information. In the lower portion of the Galena limestone the fissures become more ilregular in their course, resembling in many places a flight of stairs. Ore deposits found in oonnection with this form of fissures, are called by the miners flats and pitches. Where these fissures enter the blue limestone, the ore deposits are found mostly between the beds of the strata, but always in connection with the fissures, and are called by the miners fat openings. Here the ore deposits assume a different, although somewhat similar form, a-Ld come much nearer to that of a true fissure vein in the arrangement of their material. The oue is formed beneath a cap rock, a very hard, compact rock, forming a surface over the ore very similar to the hanging wall of a vein. Beneath this cap rock we find an aggregation of mineral matter, such as Galena, blonde, calamine, iron pyrites, cale, and sometimes heavy spar chemically deposited, arranged as in a true fissure vein. It these strata were tilted up to an acute angle, but few would be able to distinguish between this form of deposit and the forms of deposit in true fissure veins. These flat openings are important forms of ore deposits, they extend sometimes to two or three hundred!fet in width, and from one 5S half to one mile in length, along the course of the fissures; indeed,,they seldom secome fully exhausted of all their minerals; the lead may be replaced by zinc, or iron pyrites, or epar, so as not to pay expenses, but as a vein it con'tinues,:though poor. A good example of this form of deposit is found at the Linden mines, in Iowa county. Here this ore deposit commenced in the lower portion of the Galena limestone, following the fissures down through "flats and pitches" (the peculiar form these fissures take in this portion of the strata) into the blue limestone, where it spreads out into broad horizontal sheets of ore for several hundred feet wide, and has been worked continuously for nearly a mile in length. The ore in this mine is not confined to "flat openings," the usual form in the blue limestone, but is often found filling the fissures as they extend from one bed of reek to another. In this way this deposit of ore, that commenced in the galena limestone, has worked its way down into and almost through the blue limestone; in fact, entirely through, if we regard the few feet resting on the sandstone to be magnesian limestone. In one or two places it has been followed down to the sandstone. This mine has yielded not less than twelve million pounds of lead ore, and several million pounds of zinc ore; and if owned by an enterprising company and drained by an adit to its present depth, would no doubt yield many millions more, and give employment to a large number of men for many years to come. It is not my intention to give a report of this, or any other mine, I refer to it only as an example of thiq class of fissures, and form of ore deposits, and to show that the same fissures vary in form, in passing through the different beds of rock in the same strata, consequently the forms of ore deposits vary also in the vertical range of the same fissures. One other feature of this class of fissures here, and everywhere else, is, the ore deposits conform to the stratification, and instead of fcrming a continuous vein along the wall of the fissures, form a series of deposits along their vertical range. Hence we have in the galena limestone, the first, second, and third openings, and where the strata, (or this portion of it) is thick, we sometimes find the fourth. In the blue limestone beneath, we have the brown rock opening, the upper pipeclay opening, the glass rook, or dry..bone opening, the lower pipeclay opening, all following each other in succession along the vertical range of the fissures. As each of these successive openings have been reached, and the fissures below them have again contracted, and become poor, there has been a reason of doubt, as to whether there is a possibility of ore being found below that level. For imany years after the mines in the galena limestone were opened, not a man could be induced to spend a day in prospecting in the blue limestone, it was looked upon by both practical and scientil.e men as a barren rock. But now, and for many years past, our best mines have been found in this formation. It has been by a series of accidents almost, that we 59 have stumbled upon these lower deposits, believing it only when we saw them. But now we are down upon a bed of santstone, about 80 or 100 feet thick, beneath which there dawns no light. Scientific men are divided in their opinions in reference to it, some contend it is only a temporary barrier, others that, it is the bottom of our mineral strata.. This certainly is one of the most important questions conrtected with our mining interests in the lead district; one upon which the future'of these interests must depend. And while it is important that we approach this question with care, and be careful of theories formed ona imperfect data, it is nevertheless important that we concentrate what information we have, or may obtain on this point, to direct us in future operations. We know but very -little about how the fissures beneath our productive mines will behave when they enter this rock; it has been reached in but two or three places, (and in neither of these places:along the principal fissure), in these placee the fissures close up to a seam, but continue as such so far as explored. Along the streams where this rock is exposed in the lead district, no well defined fissures are noticed.. Poorly defined, irregular fissures, however, traverse the rockin all directions, and in connection with them we sometimes find evidences of chimney-like perforations, such as those referred to in this report. In the belt of iron ore to the north of the lead district, also referred to, we find fissures, and ranges of fis-.:ures in this rock, with openings similar to what we find in the limestone. And from the fact that these deposits of ochre and oxide of iron are found along this belt in connection with fissures, it is is posasible that deposits of ore of some kind may be found in this rock below the mines in'the lead district, lbut of this we have no evidence. The fact, however, that we have no evidence to prove that these fissures will be productive in or below this roek is no evidence to prove that they may not le. At this point let us examine the evidences furnikhed in similar ore districts where this has been tested. "In Cumberland, 1 locies of read ore occur in carboniferous limestone, which alternates with sandstone and argillaceous shales. The lodes are only broad and productive, when enclcsed in the limestone, split up into branches; and non-productive in the sandstone, and shales." "In D)erbyshire, the beds of the me'alliferous limestones are separated by beds of Basaltic rock, called toadstone. When a vein of lead is worked through the first limestone down to the toadstone, it ceases to contain any ore, and often entirely disappears; on sinking throagh the toadstone to the second limestone, the ore is found again, but is cut off by a lovwer bed: of toadstone, under which it appears again in the third limestone. In strong veins, particles of lead occur in the toadstone, but in very small quantities." I Ore Deposits, page 47. 3 Bakewell's Introduction to OGeology. Page 304. 60 I might multiply quotations here to show that ore districts similar to this of Wisconsinh, and found in different parts of the worid, have had to contend with diffioulties arising from the irregularity of their ore deposits, produced by beds of barren rock intervening as great, and in many instances greater than what is presented by the few feet of sandstone that divides the limestone beds of the lead district; difficulties which enterprise has overcome, or accident has removed.' How insignificant this few fet of sandstone appears when compared with the hard crystalline bed of toadstone that cuts off the veins of the first bed of the Derbyshire limestone. And when the intelligence, and enterprise of Wisconsin wavers before such an obstacle, can we blame that of Derbyshire for confining her mining operatione to the upper bed of limestone for centuries. If we are to loo:k to-the history of other ore districts, similar to our own for information, it is certainly in favor of the extension of our ore deposits into'the lower strata. Before leaving the origin of our mineral veins, and the evidences of the action of forces from below, I would refer to one other class of phenomena noticed in connection with this north, and south axis both in the lead district and immediately to the north of it. Every miner in the lead diatrict is familiar with what is called bars of rock, sometimes called sulphur bars. These bars of rock form no -distinct part in the series, but is the same:ocklocally changed. Where these bars are found in the Galena limestone, (and we usually find them there,) the rock is changed from a comparatively soft granular rock, to a very hard bluish gray crystalline rock, as hard as any trap rock can be. I have known as much as one hundred dollars per foot paid for sinking a shaft in it. These bars arecalways found in connection with our best ore deposits, the ore oftan extending away from these bars into softer rock; or as the ore approached from the other way, the ore is said to give out in a bar, or is cut off by a bar. In some places this hard crystalline rock appears to have been broken up subsequent to this hardening process, and the angular fragments cemented together by the oxide of iron in a crystalline condition, forming, what the geologist would call, a brecia, or a conglomerate with angular fragments of rock. These bars are not peculiar to any one locality in the lead district, but are found in almost every mining locality, and always near the center of these localities, or where the richest deposits are found. At New Diggings, beautiful specimens of this ".bar" rock may be found, with these angular fragments cemented together with iron pyrites. I found a very handsome specimen of this kind there, some time ago, that is now with the other specimens of the survey, in the cabinet of the Academy of Science, at Madison. To the north of the lead district, on the north side of the elevation of land, running from Blue Mounds to Prairie du Chien, and in connection with those deposits of oxide ofjron, I notiee the same or very similar phenomena. Here, between the magnesian limeston:e and the potsdam sandstone, we find, in places, beds of flinty hornstone, which are occasionally broken up into fragments in the same way, and these fragments again cemented by the oxide of iron in a crystalline condition, representing exactly this form of the bars in the lead district, with this exception, the fragments are flint or hornstone instead of lime rock, as in the lead district. Specimens of this, also, may hoe seen at Madison. A little to the north of this, along the next elevation (the Barn. boo hills) we find the same or very similar phenomena, only on a much larger scale, from the fact it is still lower in the strata, consequently exposed to more intense heat, (if the source is below.) Here we find not only bars of this altered roek, but ridges of it. The ordinary rock is sandstone (potsdam) but we find it gradually passing, sometimes into a fossil sandstone, and from that into reg. ular slate; at cthers into quartzite, and from that into the regular quartz rock. We find here, also, that beds of this quartzite, from three to four hundred feet thick have been broken up into fragments, varying in size from a man's head to a house, and hurled up in one mass around a centre of force, as at the Devils' Lake. Nothing is more evident than that the phenomena in these three different places are the results of the same general cause, modified only by local conditions., Now what is the change that this galena limestone in ttle lead district, and this sandstone at the Devil's Lake has undergone? Let us see if we can find out for ourselves by putting a piece of each under the microscope; we will try the galena limestone first. In its normal condition, (that is its unchanged condition) it is made up of small grains like sand, that are cemented together with lime, something like bricks in a wail, cemented together with mortar. When this cement is dissolved, as in the case when it is exposed long to atmospheric agencies, these little grains fall apart from each ether, and look very much like sand. When we take one of these little grains alone on the slide, and put on a higher power, we see it is a little crystal of calcareous spar, or what the miners call tiff; its little face will sparkle in the light. and its angles lie almost' as distinct as a piece of tiff that we hold in our hands. But let us try now, a piece of the bar rock, WiTe can see the same little crystals, but they are blended into one solid mass, as though they had been partially melted; and they are no longer little grains, or crystals, but a solid mass of crystals forming a rock of high crystalline texture. Now, what is true of this Galona limestone, and the bar rock, is true also of the sandstone, and the quartzite, with this difference, in one the grains or crystals are lime, or calcareous spar, in the other silicia or quartz. Now if we ask scientific men what such rocks are called, when altercd in this way; they will tell us metamorphic rocks. If w 62 ask them what it is that has produced this change in sedimentary irooks, that they now assume this crystalline character; they tell us either transmitted by igneous rocks protruded into their midst, or it is heat. If we ask in what form' this heat was presented; they tell us intensely heated water under great pressure; either is sufficient to produce it. Here we are again face to face with plutonic and hydro-plutonic forces in their endless round of reck and mineral formation andc transformation; we meet them and shall conitinue to meet them at every turn in the mineral strata. No one will be surprised if we state that quartzite i's metamorphic sandstone, but if I should state' that this bar-rock in the lead district is metamorphic limestone, the' statement would be received with surprise, and with a certain degree of distrust. And yet one is just as much a metamorphic rock as the other, just as much the result of transformation by heat as: the other. It is in these little details of the phenomena of the lead district that we'find the evidences of the action of physical forces' from below, —the lead district is full of them. A volume may be' written on them without exhausting their testimony. I have stated before, and will repeat it here, that the phenomena of the lead district and the phenomena to the north of it along the' same axis, not only fully harmonizes with the theory of the hydroplutonic origin of our fissures and ore deposits, but roadily explains them. By hydro-plutopic origin I mean, as explained before, the force of internal heat acting through water as a mediumn; a form that is related cr rather correlated to plutonic force, as heat and motion, or electricity and magnetism are related to each other; or as Prof. Tyndall would doubtless call it, a different mode of motion. UDnless we reject altogether the teachings of natural law, and regard our ore deposits as the result of chance, our choice of theory must be between this (or a similar one) or one that teaches their. surface origin by atmospheric agencies. Before we adopt the latter, let us reflect for a moment upon what we shall be called upon to explain by it. It will not be the phenomena of our ore deposits merely, but the fissures in connection with which they are found; the directive forces by which they are brought into belts of definite bearing; the axis of elevation to which these mineral belts, mineral fissures, and ore deposits belong, for they are related by indissoluble bonds that we cannot sever. And should we succeed in explainirg these phenomena in this way, we shall place ourselves under obligations to explain by the same theory, mountain ranges, lines of volcanic action, and indeed all the phenomena we call volcanic, earthquakes, plautonic, metamorphic, and hydro-plutonic, for all these phenomena ere the results of the different forms, or modified forms of the same force, and that force we know to be heat. This whole matter, then, resolves itself into this: Is the source of this heat found in the centre of the solar system, or in the cen — tre of the earth? We leave this question to the common sense of the people. CAlthough I regard the evidences furnished in the phenomena of the lead district ample to establish the relation of our mineral veins to physical forces and conditions. acting from below; and that the example of other ore districts similar to this, favors the probability of their being prcductive in the lower strata, I do not, therefore, claim that they must necessarily be so. All I claim is, that there is no reason why they may not be. And this is all that can be said of Uinexplored mineral strata anywhere, under any circumstances. But whether these fissures will extend into the sandstone, and the magnesian limestone, and become productive in these lower portions of the strata or not, is still an unsettled question,. that can be settled only by following them down by a regular process of mining. directed by the best light and information we can get. But one thing is n,)w settled beyond doubt, that was thought to be doubtful some years ago, and that is, these fissures are new known to traverse alike the different beds of the strata above the sand. stone; sometimes productive in one, sometimes in the other, sometimes in all, where they are reached in the same mine. A great many examples of this can be furnished in mines that are now open.. The Linden mines alreadly referred to, and the Crow Branch mines in Grant county, are good examples. In the latter, a rich deposit has been, and is now being worked in the blue limestone. Where the mine is worked bck into the hill to the east of the valley, there is from 80 to 100 feet of galena limestone through which the fissures. descend from the surface, with but little indications of mineral un — til within a few feet of the blue limestone, but here the ore commences and extends through the different beds of the blue limestone to where the sandstone should be, as exposed to the south of' the mine. This deposit, in -connection w'ith these fissures that can be traced through a large portion of the galena limestone, (or the, whole of that formation that is present there,) and through the entire blue limestone, has yielded not less than six, perhaps seven,. million pounds of lead ore, besides a vast amount of zinc. Now, a glance at my map will show that there is a large portion. of mineral strata in the lead district, into which these fissures are oknown to extend, and in whb'ch theyv are know;z to be productive,. that is yet untouched above the sandstone. Certainly not one mir,e in twenty, on an average, along those belts of mineral land, thas reached the blue limestone; not one in a hundred, along the two* southern belts; and yet the blue limestone is known to extend beneath those mines worked in the galena limestone above. Whetherthe strata below the sandstone is productive or not: there is enough above it to last (with cur present Corce of mining) for the next century. And from what we know c.f the'blue limestone, and the lower portions of the gulena limestone, where it has been explored, we have reason to suppose that it will be equally as productive, if not more so, than that portion of the galena limestone that has been mined. The zinc deposits are mostly confined to the blue limestone; a few instances we have where it is found in the lower portion of the galena limestone, but these places are very rare. And from discoveries recently made, it is evident that these zinc deposits are the richest in the lower portion of this formation. Good examples of this are furnished us in the mines that are now being worked at Highland and Centreville, in Iowa county. In these mines weo find galena, blende and calamine uniting to form tbe same vein; sometimes one, sometimes the other predominating. There are places, however, whers the calamine (or dry-bone) is separated from the galena: anid blende, and formed into large bodies of itself, in beds from two to" three feet thick. But very few persons either in or out of the lead district, seem to have any correct idea of the nature and extent of our zinc deposits. I speak advisedly when I say that there is zinc ore enough already discovered in the town of Highland and Blue River, to furnish, (if proper encouragement was given to mining there), material for one zinc factory, of large capacity, for a great many years to come. And this is only one small place within the limits of two townships, along the line that separates the counties of Iowa and Grant, Let me state here two or three facts, (1.) The blue limestone, wherever it has been reachedl in those mines, or mining districts that hbave been more orless productive in lead, has been productive -also in zinc. Not to the exclusion of the lead,. but thrown in as it were, as an associate of lead, arnd thus to add to the* value of the veins in this formation; an advantage we do not find in the Galena limestone above it. This lookslike one of natures laws of compensation, as though this zinc was thrown in here to pay the extra expense of miling in this formation. (2.) This zinc strata underlies the entire lead district. (3.) As before stated, it has been reached. in but a very few places in the mines. The conclusion to be drawn fromi these facts is, we have not only a large amount of undeveloped mineral strata above the sandstone, but that this portion of the strata offers peculiar inducements to mining, or will do so as soon as a steady, and reliable market for this ore is establish. ed, by mnlnufacturing it in our own state, and in close proximnity to the mines. Information obtained during this survey, on minor questions, and deductions made from facts herein stated, I shall prepare and publish in short articles (as I have booeen doing for several months past) in some of the local journals in the lead district. The principal object of this survey has been to bring to light those facts that relate to the origin of our mineral voins; their relation to the lower strata, and to mineral veins in general. In presenting them in this report, I have made no effort at style, or taste, 65 or literary display, but to present them in as p'ain, simpl- language as their nature will admit. It must not be regarded as a scientific reports but a presentation of facts for practical purposes, and for the use of practical men. Before I close this report I wish to make the following suggestions: I have found it impossible under our present system of mining, to collect material for a reliable statistical report. And inasmuch as a reliable record of the amount of ores raised in the different mines is important tj the future success of those interests, I have made the following suggesuion, or rather proposition, namely, that if parties owning mines will furnish me annually the amount of ore raised in their individual mines, or any other item of infortastion of importance, I will make a record of it, -and from those different items prepare and publish a report annually, without any expense to them or to the state. Ano her suggestion. Inasmuch as we have commenced a museum of practical geology, under the auspices of the Wisconsin Academy of Science, Arts and Letters, and have already quit e a collection of minerals, fossils and other specimens representing the practical and scientific interests of the lead district, and inasmuch as such a museum will be an honor to our State, and almost essential to the success of our mining interests, if parties in the mining region or in any other part of the State will collect and forward specimens suitable for such a museum, I will also, without expense, see that such specimens be properly arranged and proper y accredited. And I wotld like to add also that there are but few things which the State can do to aid her mining interests, that will be followed with better effect, than to provide a suitable place for such a museum, where her vast and varied mineral interests may be represented. It will be seen by my report, that a portion of the information embodied in it, has been obtained beyond the limits of the lead district, ond at considerable expense, as well as time. But as this was not provided for by the law under which I am working, I have nat charged the state with it. In fact, I have not charged the state with one dollar of expense during the survey; and although I have devoted my time, and the whole of my time, faithfully to this work, yet, inasmuch as a portion of this work was outside the limits -of the law, (although essential to my report), I have charged the state with only a portion of my time during the past summer. With sincere thanks for your kindness and encouragement in this work, I remain your obedient servant, JOHN MURRISH, Commissioner of the Survey of the lead District.