a huge shell of mineral. This extraordinary natural chamber was cleared out, a table spread within it on the Fourth of July; and a considerable company celebrated the National Anniversary within its leaden walls, about sixty feet below the surface of the earth."

The interest of the report is much enhanced by its numerous charts, diagrams and other illustrations; some sketches of prairie scenery, some drawings of minerals and fossils, and one representing the interior of a mine, the mode of sinking shafts, of drifting, &c. One of the charts will possess much interest for the scientific world. It exhibits, accurately laid down, the boundaries of "an immense coal basin, which occupies the greater part of Illinois, about one-third of Indiana, a north-western strip of Kentucky, and occasionally encroaching beyond the Mississippi, extends a short distance into the State of Missouri and into the Burlington district of Iowa." This gigantic coal-field has never been laid down before; indeed no geologist until now has had, we believe, an opportunity of ascertaining its boundaries. Its north-western margin extends over ten or twelve townships of the district surveyed by Dr. Owen, chiefly on the western side of the Mississippi.

From a table compiled by Dr. Owen and appended to the report, it appears, that the proportion of prairie, over the entire district explored, compared to timber, is in the proportion of about three to one. This would be a pretty fair proportion, were it not that about twothirds of the timber is but of dwarf growth and straggling character, there denominated "oak openings ;" and that, in some localities, especially where copper ore abounds, it is almost wholly deficient. On this important subject of fuel, Dr. Owen says:

"One of the difficulties which here occurs in reducing the ore, namely, the lack of fuel, is common to the richest copper countries in Europe. The Cornwall copper ore is conveyed partly to Swansea and other portions of Wales, and partly to Liverpool, to be smelted in a coal region; and the same vessels which thus convey the less bulky material to the more bulky-the ore to the fuel-return laden with coal to supply the numerous and powerful steam-engines required for draining and other purposes, at the Cornwall mines. And thus, in Wisconsin, if copper ore be raised in quantities, it may be necessary to convey it south, to the margin of the great Illinois Coal Field-say to the mouth of Rock River. This would require a land-carriage of from ten to thirty miles, and a water-carriage of about one hundred. The Cornwall ore is transported to a greater distance than this."

In the chapter on coal, Dr. Owen has the following additional remark :

"The coal in this vicinity (mouth of Rock River) is sure to become valuable, and to be in great demand, for the reduction of such ores (especially copper ores) as are raised in those portions of the district which are deficient in timber. Some town in this neighborhood, or a little further south, is destined to become the Swansea of Wisconsin; and to receive, in its numerous furnaces, the rich produce of the prairie mines from the north and north-west."

Dr. John Locke, of Cincinnati, whom, as our readers have seen by a former extract, Dr. Owen had succeeded in engaging on this expedition, a gentleman of well known reputation in various departments

of natural science, has added much to the value and interest of the report, by his contributions. His instruments, especially for taking magnetical observations, are said to be superior to those of any other experimental philosopher in America. The tables of barometrical observations, from which are calculated the heights, thickness, and dip of strata, are essential to an accurate appreciation of the value of the mineral region. His numerous magnetical observations will be received by the world of science as an important contribution; and their practical value is well explained by Dr. Owen in the following

extract:

"In Dr. Locke's report, under the head ‘magnetical node,' will be found an interesting account of a remarkable magnetical phenomenon, which seems to indicate the presence of some enormous mass of iron, or (if the expression be allowed) some 'subterraneous iron mountain,' which may resemble, except in position, that of Missouri. The locality indicated is on the Wapsepinicon, and the axis of the node, as Dr. Locke's chart shows, is near the line dividing townships eighty-two and eighty-three, and about six miles west of the fifth principal meridian.

“The utility of magnetical observations on the dip and intensity of the needle, as an indication of the presence of protoxide of iron, and perhaps also of great masses of the brown oxide, is undisputed; and I consider myself fortunate in having been able to add to the other materials, whereby to decide the value of the various locations of mineral lands in this district, the delicate and varied experiments of Dr. Locke."

In another portion of his report, Dr. Owen speaks of the experiments made to ascertain whether lead, in any quantity, acts upon the needle.

'I may here add, that it was a matter of much interest, and one which has been fairly and fully tested in the course of this expedition, to decide whether lead, in the greatest masses, exerts any influence upon the needle; and, as a consequent, whether that metal can be magnetically detected.

"It was well known that lead, in any ordinary mass, exerts no perceptible influence on the magnetic needle; but it remained to be proved, whether, in the enormous quantity existing throughout the lead region of his cousin, it might not act upon instruments of a construction so peculiarly delicate as those employed by Dr. Locke. No appreciable influence, however, was exerted on the needle, even in the heart of one of the richest mines near Dubuque."

Dr. Locke has also appended to his report some curious charts of mounds raised in former ages in Iowa and Wisconsin, 'exhibiting a striking resemblance to animals, and evidently intended to represent them; though the species of animal represented is, by lack of precision in these aboriginal artists, left somewhat doubtful. These mounds were carefully examined and measured by Dr. Locke in his intervals of leisure. On this subject, Dr. Owen says:

"A portion of Dr. Locke's report, including the interesting chapter on the earthwork antiquities of Wisconsin, however replete with interest to the scientific world, may be considered as touching upon topics, which, according to the strict letter of my instructions, were not embraced therein. In justice to Dr. Locke, to myself, and to the department from which we obtained our commissions, I feel it my duty to state, that these investigations into matters of mere curious research, were made without adding a dollar to the cost, to government, of the expedition. Even the

magnetical observations, which have a practical bearing, and cannot be considered supererogatory in the geological examination of a mineral region, were made, with few exceptions, either before the hour when the labor of the day commenced, or by candle-light, when other members of the expedition were wrapped in sleep; or during necessary intervals of rest, when awaiting the reports of a corps, or when unavoidably delayed by any other circumstance. They were not suffered by Dr. Locke to interfere with the other duties intrusted to him, and which he performed as strictly as if these had been his sole avocation. The antiquities were examined, to employ his own words, 'by an enthusiasm which awoke him in his tent at midnight, and sent him into the bleak fields on a November morning to finish the admeasurements of a whole group of figures before the usual time of commencing the labors of the day.'

"Thus Dr. Locke's contributions to abstract science and aboriginal history are tendered to the department and to the country as a voluntary offering; which, if not demanded by official requirements, has not been paid for from the public purse."

This is the true spirit, of economy at once and of enterprise, which ought to characterize a public officer. We are not among the number of those illiberal souls who grudge a single dollar of public money to advance the interests of science; but yet it would be opening a door to abuse, were public agents to be suffered to travel, at will, out of the record of their instructions, to gratify even a laudable curiosity, at a considerable expense, perhaps, to the department by which they are employed. We should be glad, however, to see reasonable latitude permitted, by express instructions, in such an expedition as this, where the interests of science and of the public service so nearly coincide, and where, from the nature of that service, experiments and observations of a character most interesting to science may be made at a very trifling addition to the already indispensable expense. This is the more desirable as, in explorations like the present, science is a necessary guide to practical results.

From the foregoing observations it will be inferred, that we approve the spirit of the following extract from Dr. Owen's "Remarks in conclusion:"

"I may remark, that much of what to some may seem abstract scientific research was necessary to enable me to make, with judgment and accuracy, even those formal and apparently mechanical reports, which were transmitted weekly to the respective land offices, and to the General Land Office at Washington City. To search for, and ascertain the value of, the mineral resources of a country, without strictly examining and defining the character and succession of its geological formation, would be like putting to sea without a compass; and in determining that geological character, many things that seem trifles to the uninitiated (the examination of characteristic fossil remains, for example) are of prominent and essential importance.

"I have endeavored, in the conduct of this expedition, and in the framing of the present report, to preserve a due medium between a latitudinarian construction of my official instructions, involving an expenditure of public funds for objects not contemplated in the original projection of the enterprise, on the one hand; and, on the other, a contracted and illiberal interpretation of the same; an adherence to the latter at expense of the spirit; which saves without economizing, and destroys the very object of such an expedition, by way of curtailing its indispensable expenses. How far I have succeeded in the endeavor, others must judge."

In an extract already quoted by us, allusion is made to the fact, that several thousand valuable specimens of ores, ore-bearing rocks, fossil remains, soils, &c., were made in the course of the expedition. We heartily concur with Dr. Owen's views in regard to the disposition of these specimens, as here given, from his concluding chapter:

"I trust that I shall not be considered as over-stepping the sphere of my duty, if I suggest the importance, in an economical as well as scientific point of view, of having these specimens arranged in some suitable apartment at the seat of government, as the nucleus of a National Cabinet. Not only the man of science, but the practical miner, would inspect such a collection with deep interest; and it might be the means at once of gratifying laudable curiosity and of stimulating commercial enterprise.

"I doubt whether any other Geological Cabinet, public or private, has its specimens located with the same minute accuracy as, from the nature of this survey, I have been enabled to locate these; and it is accuracy of location which gives to all geological and mineralogical specimens their chief value."

There is, toward the close of Dr. Owen's report, an interesting chapter on the soils of the explored district. Of these Dr. Owen analyzed fifteen specimens; and found them, unlike the soils of most other mineral regions, generally of rich quality.

Professor Hitchcock, of Massachusetts, published, in the year 1838, a similar analysis of one hundred and twenty-five specimens of soil, taken as an average throughout that State. Dr. Owen shows, by comparing Professor Hitchcock's table and his own, that the Iowa and Wisconsin soils contain of geine, or organic matter, (the ingredient which chiefly imparts to a soil its fertility,) nearly one-third more than the average per-centage of the soils of Massachusetts. One specimen of rich valley soil, analyzed by Dr. Owen, gave the enormous quantity of twenty-six per cent. of organic matter, while the average quantity of organic matter contained in the Massachusetts soils is about seven and a half per cent. It is a curious fact, too, and may lead to important practical conclusions, that, so far as these tables extend, the quantity of organic matter in the soils (consequently their probable fertility) is, almost to mathematical accuracy, in the inverse ratio of their specific gravity.

Dr. Owen has also given elaborate analyzes of the various ores, ore-bearing rocks, coal, &c., found over the district. In a word, he seems to have neglected nothing which could furnish to Congress and to the public generally the means of correctly estimating the extraordinary resources of the region to which his attention was directed.

We trust that this expedition will give encouragement to Congress to prosecute with vigor, and under some well-digested system, the work which has been yet but begun. Between the Mississippi and the Pacific what limitless mines of wealth may be hid! A little enterprise on the part of government-an expenditure which may be repaid ten times over by the value of the reservations made at the

geologist's recommendation-how much may thus be effected in bringing to light these hidden mines of wealth, many years, even centuries, before they might be discovered or appreciated without such pioneer explorations!

It has occurred to us, that at the same time at which the Public Lands of the United States are surveyed, they might be geologically explored also by attaching to each corps of United States Surveyors a prac-tical geologist. We cannot but think that the expense would be well repaid. A merchant does not think of selling his goods until he has ascertained their quality. Ought we not, upon the same principle, to take measures for discovering the character and value of our Public Lands before we bring them into market?

POLITICAL PORTRAITS, WITH PEN AND PENCIL.* NO. XIX.

BENJAMIN TAPPAN, SENATOR FROM OHIO.

WITH the close of the Democratic State Convention of the 8th of January, 1836, the Presidential campaign commenced in Ohio with unexampled activity. At this great meeting of the honest yeomanry of the State, he and many of his long tried and experienced associates forewarned the young men that their opponents would make unparalleled efforts to crush the spirit of democracy, and obtain a triumph for their long cherished principles and policy. He urged upon them to observe that eternal vigilance which is the acknowledged price of liberty, in keeping before the country the great measures for which they were contending, and by no means to allow themselves to be led astray or to wage the contest in defending immaterial issues, and personal questions, involving no higher object than individual preferences for men. He assured them that the known opinions of their favorite candidate would enlist and arouse in opposition to him and them every latent principle and energy of ancient federalism; that Mr. Van Buren's objections to a paper currency, except for large transactions and mercantile exchanges, his anxious desire to confine banking operations to their appropriate sphere and original functions, and above all, his hostility, to the policy which tolerated driving from common use, as the ordinary circulation among farmers and tradesmen, the gold and silver coins, by means of small bills, would bring into the service of their enemies elements of warfare and influences, that would operate unseen, but with great power; and that nothing

* Concluded from the June Number, Vol. vii, No. xxx, p. 562.