compelled to act across the beds instead of in their strike. Hence the straits of Mackinac are located in that place. On the Island of Mackinac these for mations are all represented, the Corniferous occupying the most elevated parts, and the Salina barely rising above the water. They also occupy the coast to the west as far as Gros Cap. Crossing to the south side of the straits, thus passing over the outcrop of the Salina, we step on the lowest parts of the Waterlime Group. The following provisional arrangement, in ascending order, has been made of this formation, and the overlying Corniferous and Hamilton. Future examinations were depended on to verify it, and the positions of one or two members are quite uncertain; yet it will be found substantially correct, and reliable for most practical purposes. 1. WATERLIME. 1. Flaggy and shaly limestone; aluminous; hydraulic; containing at least one bed of about six feet, very hard, compact and fine-grained limestone, and a bed of blue clay. Thickness, 50 feet. 2. Black limestone; almost non-fossiliferous, hard, fine-grained, and compact; seen in the bed of Sunken Lake, Presque Isle County. Thickness, 20 feet. 3. Bituminous shale, like coal. Thickness, 10 feet. 4. Argillaceous, blue-black limestone, hard, and fine-grained, non-fossiliferous. Thickness, 15 feet. 2. ORISKANY SANDSTONE. 5. A brown magnesian limestone; arenaceous, coarse and granular, having much the appearance of a sandstone, mainly non-fossiliferous; seen at the bottom of the ledge at Sunken Lake, and near the base of Crawford's quarry. Thickness, 10 feet. 3. CORNIFEROUS AND HAMILTON (unseparated). 6. A series of beds of fossiliferous, magnesian limestone, greatly exposed on the south shore of Little Traverse Bay, and at the south end of Cheboygan (Black) Lake. Some of these beds furnish a beautiful crinoidal limestone. Thickness, 75 feet to 100 feet. 7. Black bituminous limestone; soft, and fossiliferous. Thickness, 6 feet. 8. Crystalline, crinoidal bed, like the summit of the bluff at the head of Cheboygan lake.' Thickness, 10 feet.. All these except the last two, are concerned in the geology of the Cheboygan region. No. 1 is probaly seen in the rock near the light-house at Mackinaw city, and also gives rise to Waugoshance Point and reefs, occupying also the most of the surface of the peninsula to the south as far as to a line drawn from Little Traverse through the northern shore of the line of inland lakes to the north side of Hammond's Bay. It is also supposed to form the coast about Presque Isle and False Presque Isle. [NOTE.-There are some indications that a bed of clay or blue shale, like the Salina, intervenes between Nos. and 2, giving rise to the basins of Little Traverse Bay, the inland lakes of the Cheboygan region, Hammond's Bay, and perhaps to Grand and Long lakes in Presque Isle county. Long lake has been produced from the subterranean erosion of this or some other bed of shale. The same is true of Sunken Lake. This shale bed has been nowhere distinctly observed. It may have a thickness of over 100 feet. J 1 But not that bed. That bed is believed to be a part of No. 6. No. 2 has not been seen in the Cheboygan region, its presence there being known only by the occurrence of its associate, No. 3. Its position immediately above a shale bed probably accounts for its being hid deep in the drift, or covered by the water where other members of the formation higher up are seen. A local disturbance (of that kind) has thrown it below the water at the head of the Cheboygan lake, where there is a dip of ten degrees towards the N. E. It is visible in its natural beds in T. 34 N., R. 5 E., S. W. 1, N. E. 4 Sec. 26. No. 3 occurs in outcrops on the S. W. shore of Burt's lake, where it acquired some years ago quite a reputation among the Indians, aided by one or two speculative land hunters, under the name of coal. No. 4 has not been actually detected in the Cheboygan region, its location there being an inference from the study of this formation in other localities. It must lie near the base of the high land at the S. W. end of Burt's lake, and perhaps would be seen in the rapids in the Cheboygan, Pigeon, and Black rivers, south of the lakes into which they flow. These places have not been visited geologically. No. 5 forms the bottom of the ledge at the head of Cheboygan lake, where it shows about 18 inches. It is an even-bedded, brown, arenaceous limestone, with some rusty cavities. It may also probably be seen in the rapids already mentioned. No. 6 composes the principal portion of the bluff at the head of Cheboygan lake, and shows there a thickness of forty or forty-five feet. The lower 30 feet consist of a magnesian limestone; thin-bedded and thick-bedded († to 12 inches); sometimes shaly; on the weather surface having the color and frequintly the compactness of lime; on a fracture, having the color of ashes, a light gray; compact, but also argillaceous and breaking under the influence of the weather, into blocks of all sizes; but little fossiliferous. The upper ten or fifteen feet consist of a beautiful, compact, crystalline crinoidal limestone, containing many fossils. Nos. 8 and 9 are not supposed to occur in the Cheboygan region, although they may exist in the rapids already mentioned. In regard to the economic value of this series of rocks, it may be remarked. in general, that they abound in calcareous and aluminous ingredients, and impart those phosphates and alkalies to the soils of the region which serve to make them the strongest and most productive. Their effect is of the same kind, though not so powerful, owing to the heavier mask of the northern drift, as that of the Cincinnati Shales on the "Kentucky blue grass region," and on the southwestern part of Ohio. Where the Salina and other shale beds have their legitimate effect on the soil, it is of a bluish clay. The clay of a pink or copper color belongs to the drift, but its origin is more remote. Both are found in the Cheboygan region. The soil at the mouth of the Cheboygan river, on which the village of Cheboygan stands, is a good example of the former. The copper-colored clay can be seen in the bluffs which line the river along the rapids, above the forks of the Cheboygan. Besides these two varieties of clay soil, there are various small patches of prairie loam, and also of a strong calcareous marl. The former contains varying proportions of carbonate of lime, oxide of iron, and animal and vegetable matter in process of decay. It owes its superior fertility to the ammoniacal qualities of the decaying organic matter. The latter contains an excess of carbonate of lime derived from the disintegration of rock or the shells of molluscs, together with considerable alumina, or clay, and sand. These also, are very desirable and useful soils, furnishing that variety which will often enable a single farm to produce a great variety of products. Deposits of marl, suitable for use as a fertilizer, or for the manufacture of quicklime, are of frequent occurrence. It must be remembered, however, that the prevailing feature of the soil of the entire region is a silico-calcareous sand, which, mingling in its varying proportions with the foregoing heavy soils, adds the qualities of lightness and quickness, together with ease of cultivation. There are some sandy plains of little value for farming, but the most of the country is rolling, often picturesque, especially near the lakes. More especially as to the economic value of the rocks themselves: If the shales of the Salina can be found anywhere above the surface of the lake, they will furnish a valuable clay for bricks or for pottery. The same may be said of the bed of shale supposed to be between Nos. 1 and 2. Owing to the absence of peroxide of iron, the bricks would probably be of a light color, resembling the cream-colored Milwaukee brick. No. 1. This bed is hydraulic. On the Thunder Bay river it has been manufactured into waterlime. Professional chemists pronounce it a stone of superior hydraulic properties. In the State of New York, aud at Louisville, Kentucky, it has been extensively manufactured into waterlime cement. No. 2 will supply a handsome and durable building stone. In many places it appears like an ornamental marble; its deep black color, however, will not be found durable when exposed to the weather. No. 3 will burn like a bituminous coal, but it will be a great many years before it will be of any economical value. No 4. Owing to the fine and uniform texture of this member of the Waterlime, it will probably supply a material suitable for hones and oilstones. It will also make a fine building stone. No. 5 will make a good building stone, and can be burned into quicklime. No. 6 contains some handsome beds of crinoidal limestone or marble. It is destined to be greatly used as a building stone, even for ornamental purposes. It will also supply unlimited quantities of excellent quicklime. Besides the materials for building found in these natural beds, the northern boulders, which are common in all parts of the district lying on the surface, will furnish a very useful and permanent building stone. In regard to the prospect for the manufacture of salt, geology simply testifies that the great Onondaga Salt Group underlies the entire district probably within three hundred feet, and that there is no evidence that it will not prove as saliferous in the Cheboygan region as at any other place. The conditions also seem favorable for the enterprise of artesian wells. At about 150 feet after striking the rock, there would be many chances for an artesian overflow, but at the depth of about 800 feet there would be many more. In conclusion, the indications of the future prosperity of the Cheboygan and Mackinac regions, so far as they may be learned from a study of their geology, are very flattering. The rocky structure is of that persistent nature that enabled it to rise to a great extent above the drift of the later period of the posttertiary, and escape the thick deposit of sands which are so marked a feature of the sandy plains in many extensive tracts in Michigan. Hence, the soil is more frequently a clay or clayey loam, with a mingling of desirable quantities of sand. It is a soil which we generally find clothed with beech, maple, hem lock, and kindred hardwoods. If it contains white pine, as it not unfrequently does, the trees are scattered and "badly mixed" with the hard wood, but are of the largest size and finest quality. Sometimes such solitary pines are designated "cork pine." This lays the foundation of a rich agricultural district: although the pioneer settlements in such a district may have been due to the lumber interest, yet that cannot long remain in the ascendency. Indeed the Cheboygan region is rapidly outgrowing it, and is developing other and more permanent elements of prosperity. The country is rapidly filling up with farmers. The village itself has not absorbed the entire population, but it is spread throughout the contiguous country. Supplementary to the natural agricultural advantages, there is no lack of those other natural resources, the fruits of which always follow, sometimes at great cost, and adorn the more rude handiwork of the pioneer. Good stone for building, clay for brick-making, water-power for manufactures, and means of easy transportation, are combined to that degree and in such close proximity, that it is doubtful whether there is a more promising field for the establishment of manufactures anywhere in the State. The series of beautiful inland lakes, connected by large streams of clear water, unrivalled for their beauty as well as their utility, will continue to afford, as they do now, a pleasant and easy means of communication between the most distant settlements, when the exigencies of development shall have demanded larger craft than the red man's canoe, the lumberman's bateau or the punt of the farmer. Ann Arbor, Mich., May 12, 1871. EXPERIMENTS IN PIG-FEEDING. BY M. MILES, SUPERINTENDENT OF STATE AGRICULTURAL COLLEGE FARM. To the President of the State Agricultural College: The following report of experiments made in the Farm Department during the year 1871 is respectfully presented: The conflicting results obtained in feeding experiments arise, to a great extent, from differences in the conditions observed in making the experiments, and from the general neglect of the elimination of errors by a repetition of the experiment under the same conditions. A single feeding experiment is of but little value, when considered by itself, from the fact that the complex character of the processes involved leaves us in doubt as to the elements that determine the result. Thus far the feeding experiments conducted in the Farm Department have been made with reference to one leading object, viz., the determination of the feeding value of raw corn meal when fed by itself, for the purpose of obtaining a standard of comparison in experiments with corn in other forms and when mixed with other foods. It is undoubtedly true that any single article of food will not give as good results, when fed by itself, as may be gained by feeding with it a proportion of other foods somewhat different in character. In feeding mixed foods, however, the complexity of the conditions involved. makes it difficult, if not impossible, to determine the influence of each particular upon the results. The first step in experiments with mixed foods should be the determination of the value of some of the leading foods when fed by themselves, thus securing a standard of comparison by which the results obtained with the mixed foods may be measured. As the verification of the experiments already made seemed to be of greater importance than the beginning of a new line of investigation, the experiments. in feeding for the year 1871 are but a repetition, under the same conditions, of those made during the three preceding years.* At the beginning of the experiment, August 22d, twelve pigs were put in the pens as follows: See Reports of the State Board of Agriculture as follows: 1868, p. 78 to p. 97; 1869, p. 53 to p. 71; 1870, p. 75 to p. 92. |