hydrographer. To this separation of hydrography and geography some objection has been made, but not yet supported, as far as we have seen, by any good reasons. The study of rivers is generally admitted to be an important part of geography: why then, it is asked, not include hydrography, as above explained, in the science? It is a sufficient answer to a mere objection put in the way of question, to reply by asking another question: the proper answer to this objection then will be-why should we include it? The division of the globe's surface into land and water seems a very natural one, and the knowledge of this surface will, in our opiniou, be best forwarded by following the obvious division which nature presents to us. We assign the rivers to the geographer, because the hydrographer cannot trouble himself about them any further than concerns their outlets and tide water. It is in such places as these, and at the heads of bays and inlets, that the hydrographer and geographer will sometimes meet and have a little friendly communication; but neither of them, if they are wise, will seek to enlarge his domain by encroaching on that of his neighbour.

The next object of the geographer, and, in fact, his great business, is to determine the form of the surface of the land. If we knew the latitude and longitude of each place, and its perpendicular elevation above any given level, we should know all the irregularities of the earth's surface, which, however trifling they may be when compared with the whole mass, are of the highest interest to man, as without them the earth would not be suited for his habitation. The ascertaining of the actual and relative heights of places on the earth, which may be termed hypsometry (height-measurement), is a branch. of geography that requires both to be extended and rendered more exact. But the number of points that we

can ever expect to ascertain will always form a small part of the whole surface of a country, and we must therefore have recourse, by way of supplement, to geographical description. This branch is necessarily less exact than the former, inasmuch as it must avail itself nearly altogether of words, which never convey with perfect accuracy either the facts of nature or the impressions of a writer. It necessarily involves the use of a great many terms, such as mountain, valley, plain, which, from their nature, can never be defined with such accuracy as to render the use of them altogether free from objection. Still we must attempt, partly by numerical values, whenever this is practicable, and partly by description and by representation on paper, to give as accurate an idea as we can of the mountains, valleys, plains, and all the irregularities which mark the surface of a country. Here the pursuits of the geographer and the geologist have certain points of contact. The geologist, though his inquiries are more particularly directed to the position of rocks and the nature of their contents, cannot overlook the general configuration of the surface. Nor will the geographer, though his special object is to ascertain the form of the surface, neglect to observe such changes as are evidently in progress and are altering the character of that which it is his object to estimate. The general description of mountain-systems, including the direction of the main masses, and the area occupied by them, the junctions of different groups, the elevations of the chief points, the determination of the drainageboundaries, &c., is now classed under the title of Orography. This term excludes, or it ought to exclude, all that refers to the particular mineral composition of mountains: it treats specially of their form. But in doing this, in describing scarped sides, flat tops>

needle peaks, or broad round backs, we conceive it is the business of the geographer to state, in general terms, the nature of materials which have such definite and characteristic forms.

The next important branch of geography is the description of the sources, course, and volume of rivers; the description of fresh-water lakes is included in this head. This branch leads to a more minute examination of those boundaries which determine the course of the waters that rise from the earth in springs, and of those which, descending in rain, find a more immediate channel by which to pass off. The drainage of a country is, as a general rule, marked out into a number of great divisions, often called, whether with propriety or not, basins, each basin has its main drain, with a number of smaller drains running into it. To determine the limits of each great basin, or the boundary lines of the surface drained by the great rivers of a country, is a necessary step towards an accurate knowledge of it.

The study of rivers leads to a more careful consideration of the slopes along which their waters descend towards the general recipient, which is either the ocean, an inland sea, or lake. These slopes are generally bounded by high land on each side, constituting, with the lowest level between them, what are called valleys. The form of these valleys, through which we trace rivers, is almost infinitely diversified, and the study of them may be said to be the most interesting and useful part of geography; they are the chief seats of man's abode, and of his culti

It might perhaps be advisable to use another term, as the term basin is used by geologists, and in a different sense. Basin however is well established in geographical description, as indicating the whole space drained by a river: " valleys" of course are included within " basins," and are parts of them. (See Darby's United States, p. 59, note.)

vation, and their waters give life and activity to his social intercourse. Various names have been already given to valleys, according to their form, and in countries where the features of nature are on a large scale, some of these names are appropriate and convey an accurate idea. When a river runs in a long valley, bounded by parallel ranges of high land, of which we have numerous striking instances, its course lies in a longitudinal valley. But the course of a river is often changed, and it runs from a valley of the kind just described either into another valley or a completely different kind of country; this passage is generally effected by its..waters taking a direction which makes a considerable angle with the line of the mountains and passes through them, either by a circuitous winding course forming a succession of transverse valleys, or by one short and narrow passage, to which the name valley cannot be given; the name of gorge has been sometimes used to express a passage of this kind *. But a more accurate examination of valleys will show the propriety of some additional terms; for as valleys have evidently been produced in more ways than one, so their forms are too various to be included in two or three terms. Some rivers do not run in valleys, according to any definition of the term valley as it now exists. Many rivers which flow through a flat region have probably grooved out a channel in the earth, to allow a free passage for their waters. The depth and breadth of these grooves are evidently dependent on the volume of water and the nature of the ground, and, we believe, are deepest in all countries where the occasional floods are the greatest. A river may thus hollow out a

See Strabo's description of the Gorge of the Pyramus (p. 536. Casaub.); and the Passage of the Potomac through the Blue Ridge, in Jefferson's description.

channel several hundred feet deep, as the Ohio river, in some parts, has done, till it has made a passage large enough to hold any body of water that may come down. These excavations look like valleys, and are called so, but they seem to us to require a different name from other valleys. The hills which bound some parts of the Ohio and other rivers of the Mississippi valley have been sometimes appropriately called River-hills: seen from the water they present slopes, and sometimes tolerably steep sides; but their tops are the level of the plain, and have been cut into hill shape by the lateral streams which fall into the main channel. This theory of the formation of the bed of the Ohio may be true or not: we give it here as it is given by the authorities referred to; and we do this merely with the view of drawing attention to the actual form of the river's bed. As to the hypothesis itself, of the channel of this or other rivers having been formed solely by the action of water, we may remark, that it is not to be overthrown, as some would wish to overthrow it, by a few loose comparisons with other rivers which are of a different character. Those who will take the pains to begin to study the surface of the United States, will find they have yet much to learn; for considered as a whole, the country presents in its physical character and its climate many features which, if not peculiar to it, are certainly not seen in all parts of the world. Those who wish to look further into this subject, may consult Darby's valuable work (p. 298, &c.) on the United States, without the study of which, or an actual knowledge of the country, any remarks upon the geography of the United States can have but little value.

See the quotation in James Stuart's America, ii. 402, &c., Major Long's Expedition to the Rocky Mountains, i. p. 38, &c., and Darby's View of the U. S.