quence of the researches of its votaries, many striking and important facts in relation to the structure of the earth and the changes it has undergone, have been brought to light. Many of the facts which this science discloses have a tendency to convey to the mind impressions of the wisdom, and particularly of the power of the Creator, in those stupendous forces which produced the convulsions and changes which have taken place both on the surface and in the interior strata of the globe. They are likewise applicable to various practical purposes. A minute and circumstantial knowledge of the various facts which have been ascertained by geologists in different countries, may be of extensive use to those employed in mining operations, when searching for coal, fossil salt, or metallic veins, and might prevent many ruin. ous speculations to which ignorant projectors are frequently subjected. In excavations for the purpose of forming canals, tunnels, and rail-roads-operations which are now going forward in almost every part of the civilized world-a knowledge of this subject could not fail to be highly beneficial to all parties engaged in such projects. Besides, the study of this science is intimately connected with Scripture history and theology, and its facts, when viewed in a proper light, have a tendency to elucidate certain portions of the Sacred writings, and to illustrate the harmony and the connection which subsist between the visible operations of the Creator and the revelations of his word. For these reasons, it might be expedient to communicate to the young a general idea of some of the leading facts connected with geology, without perplexing them with any of the speculations of philosophers, or the theories which have been formed to account for geological phenomena; leaving them to deduce their own conclusions at a future period, when their knowledge of such subjects shall be increased, and their judgment matured.

A brief description might be given, in the first place, of the solid parts of the earth, of the various strata of which they are composed, and of the classifications which geologists have made of the different kinds of rocks. These rocks are usually arranged under the following classes:-1. Primary rocks, which compose the grand framework of the globe, which form the most lofty mountains, and extend to the greatest depths yet penetrated by man, and below all the other formations. The substances of which such rocks are composed, are granite, gneiss, mica-slate, hornblend, granular quartz, &c. but never contain salt, coal, petrifac

by selecting the descriptions, exercises, and more interesting portions of each, and combining them into a volume calculated for the meridian of our own country.

tions, or any remains whatever of organized substances; and therefore are supposed to have been formed before the creation of animals or vegetables.-2. Transition rocks, which include those rocks that lie over the primitive, and are composed of the larger fragments of the primitive rocks. They contain graywacke, transition limestone, slate, sandstone, &c. Shells are sometimes found in them, but no remains of land animals or vegetables. It is supposed they were formed next after the primitive rocks, and after the creation of some kinds of organized beings.-3. Secondary rocks, which lie upon the transition rocks, and appear like deposites, composed of grains which once belonged to primitive rocks. The principal secondary formations are coal, chalk, secondary limestone, oolite, millstone, grit, &c. which contain petrifactions of animal and vegetable substances. - -4. Tertiary strata, which consist of beds of clay, sand, marl, and the newer limestone deposites. These formations are considered as newer than the secondary, and contain abundance of fossil shells and plants, along with the bones of quadrupeds and fishes.-5. Volcanic and basaltic rocks, which owe their origin to volcanic fire, and are sometimes forced up to the surface of the earth in a melted state, by the action of subterraneous heat. The principal volcanic rocks are basalt, lava, and greenstone.-6. Alluvial strata, which include deposites that are made of broken strata, consisting of sand, mud, clay, pebbles, &c. which are formed by the currents of rivers, and other causes now in operation.

These classifications of rocks and formations might be illustrated by such figures as in the annexed cut, which is taken from Woodbridge's "System of Universal Geography," where Fig. 1. represents the strata of the earth, P the primary strata, T transition, S secondary, A Alluvial, B basaltic, V vein, b bed. Fig. 2, represents a section of the earth between latitude 40° and 45° north. In conjunction with such pictorial representations, a cabinet of materials should be procured, containing at least the following: quartz, mica, talc, feldspar, limestone, argillite, or slate, hornblend, gypsum and chlorite, which form what has been termed the alphabet of geology. Besides those, specimens should be procured of basalt, gneiss, greenstone, lava, porphyry, graywacke, and other substances mentioned above. About thirty specimens in all are sufficient for illustrating the classes of geology. Without an exhibition of these, in connection with geological descriptions, no definite ideas can be conveyed to the mind of the student on this subject.*

* Books on geology have, of late years, increased both in number and in the interesting nature of the discussions they contain. The names of

SECTION VIII.-Astronomy.

It

Astronomy is a science which has for its object to explain the motions of the heavenly bodies, their various aspects, and the facts which have been ascertained in the planetary system, and throughout the region of the fixed stars. This is a subject of considerable interest and utility. It is intimately connected with geography, navigation, agriculture, commerce, chronology, and other arts and sciences, and has lent its aid to promote their improvement. The study of it is likewise attended with many pleasures and advantages in a moral, intellectual, and religious point of view. It expands the range of the human intellect, and unfolds to our view the most striking displays of the perfections of the Deity, particularly the grandeur of his Omnipotence. sets before us objects of overpowering magnitude and sublimity, and demonstrates the unlimited extent and magnificence of the universal empire of the Almighty. It has a tendency to raise the soul above grovelling pursuits and affections, to inspire hope, reverence, and humility, and to excite to the contemplation of objects far surpassing every thing we behold in this terrestrial scene, and worthy of the dignity of immortal minds. In short, it prepares the mind for the employments of the future world, and demonstrates, that the Creator has it in his power to distribute endlessly diversified streams of felicity, among every order of his intelligent offspring, throughout all the revolutions of eternity. It is a subject, therefore, on which a certain portion of information should be communicated to the young, and to every human being.

In communicating to the young instructions on this subjectinstead of commencing with definitions. of astronomical terms, and a vague description of the solar system, as is frequently done, -the pupils should be gradually prepared for acquiring a general knowledge of the principles of the science, by being taught to

Bakewell, Macculloch, Delabeche, Buckland, Ure, Lyell, &c. are well known as cultivators of this department of natural science. The new edition of Mr. Lyell's "Principles of Geology," in 4 vols. 12mo. lately published, is perhaps one of the most luminous and attractive works which has hitherto been published on this subject-though perhaps somewhat deficient in what relates to the primary and secondary rocks, and embodying certain` statements which some will be apt to consider as scarcely consistent with the records of sacred history. Dr. Comstock, of Hartford, State of Connecticut, has lately published, in a duodecimo vol. of about 340 pages, an interesting .work, entitled, “Outlines of Geology," which contains a popular and comprehensive view of this subject, and is peculia-ly adapted to the instruction of general readers.

observe, with their own eyes, the motions and general phenomena of the heavens. The first object to which their attention might be directed, is the apparent motion of the sun. On some clear evening, in the month of June, (in our northern latitude,) they may be placed in a situation where they may behold the setting sun, and be desired to take particular notice of such objects as mark the place of his going down. Next morning, or the first clear morning afterwards, they may be placed in the same situation, and, having first requested them to point to the place where the sun disappeared the evening before, their attention should next be directed to the point of his rising, and to mark the terrestrial objects in the direction of which he appeared to rise. The dif ference between the points of his setting and of his rising should be particularly impressed upon their minds. On this day, too, about twelve o'clock, they should be directed to attend to the sun's meridian altitude. These observations may either be accompanied with certain appropriate remarks, or the pupils may be left, in the meantime, to ruminate upon them, to consider them simply as facts, which may be afterwards adverted to, and to form their own conclusions. Similar observations may be made from the same spot about the 23d September, and particularly about the middle of December, when the direction of the rising and setting sun, his meridian altitude, and the apparent diurnal arc he describes, will appear very different, when compared with the observations made in the month of June. Their attention might next be directed to the phases and motions of the moon. About three days after new moon, when the lunar crescent first makes its appearance, they may be directed to mark the form of the crescent, the most conspicuous stars in its vicinity, and its apparent distance from the place where the sun went down. Every clear evening afterwards, the gradual increase of the crescent, its motion among the stars, and the apparent distance it has moved during every successive period, should be particularly marked, till it arrive at the eastern part of the horizon after the sun has set in the west, when it will appear a full enlightened hemisphere. During the months of August, September, and October, when the effect of the harvest-moon is apparent, they may be directed to trace the gradual diminution of the full moon, through its different stages of decrease, till it assume the form of a half moon or a large crescent. During the months of March or April, their at tention may be directed to the difference in the time of its rising on each successive day after full moon, from what takes place during the months of harvest,-in the one case, namely, in harvest, there being only 20 minutes of difference after full moon, in