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In this manner the sea supplies sufficient humidity to the air for furnishing the earth with all necessary moisture. One part of its vapours fall upon its own bosom, before they arrive upon land. is arrested by the sides of inountains, and is compelled, by the rising stream of air, to mount upwards towards the summits. Here it is presently precipitated, dripping down by the crannies of the rocks. In some places, entering into the caverns of the mountains, it collects iu those receptacles, which being once filled, it then overflows; and, breaking out by the sides of the hills, forins single springs. Many of these run down by the valleys, and uniting form little rivulets or brooks; many of these, meeting in one common valley, and gaining the plain ground, become a river; and many of these uniting, make such vast bodies of water as the Ganges, the Nile, the Danube, and the Rhine.
But there is still a third part of the vapour exhaled from the sea, which falls upon the lower ground, and furnishes plants with their wonted supply. The circulation does not rest even here; for it is again exalted into vapour by the action of the sun; and again returned to that great mass of waters whence it first arose. This, according to Dr. Hally, is the most reasonable hypothesis; and much more likely to be ; true, than that of those who derive all springs from the filtering of the sea waters through certain imaginary tubes or passages within the earth; since it is well known, that the greatest rivers have their most copious fountains the most remote from the sea. See Phil. Trans. vol. ii. p. 128.
The Doctor's opinion, we believe, is the most generally adopted; yet, after all, it is still pressed with great difficulties; and there is still room to look out for a better theory. The perpetuity of many springs, which always yield the same quantity of water, even when there is least vapour or rain, as well as when there is the greatest, is a strong objection, Derham, in his Physico-Theology, mentions a spring at Upminster, which he could never perceive by his eye to be diminished, even in the greatest droughts, when all the ponds in the country, as well as an adjoining brook, have been dry for several months together. In the rainy seasons. also, it was never overflowed, except sometimes, perhaps, for an hour or so, upon the immission of the external rains. He therefore concludes, that if this had its origin from rain or vapour, there would be found an increase or decrease of its water, corresponding to the causes of its production.
Thus are we tossed from one hypothesis to another. Must we at last be content to settle in conscious ignorance? This, however mortifying, is often the case after the most painful research in philosophical subjects. But perhaps many of our readers will think, that the origin of rivers is best accounted for by an union of the different schemes of De La Hire and Dr. Hally. Happy however for mankind the vapours continue to arise, the rains to descend, the springs to flow, and the rivers to run. Thus the Deity ceases not to bless his creatures with a profusion of goodness, while the wise men of the world mutually confound each others account of his method of distributing his favours.
Some philosophers, though they are at a loss to account for the origin of rivers, think themselves by no means so as it relates to their formation. Varenius says that rivers are artifical. . He boldly asserts that their channels have been originally formed by the industry of man. His reasons are, that when a new spring breaks forth, the water does not make itself a channel, but it spreads over the adjacent lands. Thus, say3 he, men are obliged to direct its course; or, otherwise, nature would never have found one. He enumerates many rivers that are certainly known, from history, to have been dug by men. He alleges, that no salt water rivers are found, because men did not want salt water; and as for salt, that was procurable at a less expence than digging a river for it. Although it costs a speculative man but a small expence of thinking to form such an hypothesis; yet it may, perhaps, be a trial to the reader's patience to detain him longer upon it.
Though philosophy be thus ignorant, as to the production of rivers, yet, the laws of their motion, and the nature of their currents have been very well explained. All rivers have their source either in mountains or elevated lakes; and it is in their descent from these situations, that they acquire that velocity which maintains their future current. At first their course is generally rapid and headlong, but it is retarded in its journey, both by the continual friction against its banks by the many obstacles it meets with to divert its stream, and by the plains becoming more level as it approaches towards the sea. If this acquired velocity be quite spent, and the plain through which the river passes be intirely level, it will, notwithstanding, still continue to run from the perpendicular pressure of the water, which is always in exact proportion to the depth. This perpendicular pressure is nothing more than the weight of the apper waters pressing the lower out of their places, and consequently, driving them forward, as they cannot recede against the stream. As this pressure is greatest in the deepest parts of the river, so we generally find the middle of the stream most rapid; both because it has the greatest motion thus communicated by the pressure, and the fewest obstructions from the banks on either side.
Rivers thus set in motion are almost always found to make their own beds. Where they find the ground elevated, they wear its substance away, and deposit the sediment in the next hollow, so as in time to'make the bottom of their channels even. On the other hand the water is continually gnawing and eating away the banks on either side; and this with more force as the current happens to strike more directly against them. By these means, it always has a tendency to render them more strait and parallel to its own course, Thus it continues to rectify its banks, and enlarge its bed; and, consequently, to diminish the force of its stream, till an equilibrium is obtained between the force of thie water, and the resistance of its banks, upon which both will remain without any further mutation. Happy is it for inán that bounds are thus put to the erosion of the earth by water'; and that we find all rivers only dig and widen themselves but to a certain degree. In thoše pláitis and large vallies where great rivers How, the bed of the river is usually lower thản any part of the valley. But it often happens, that the surface of the water is higher than inany of the grounds that are adjacent to the banks of the stream. If, after inundations, we take a view of some rivers, we shall find their banks appear above water, at a time that all the adjacent valley is overflown. This proceeds from the frequent depositions of mud, and such like substances, upon the banks, by the river's frequently overflowing; and thus, by degrees, they become elevated above the plain ; and the water is often seen higher also. Rivers, as every body has seen, are always broadest at the mouth; and grow narrower towards their source. But what is less known, and probably more deserving curiosity, is, that they run in a more direci channel as they immediately leave their sources, and that their sinuosities and turnings become more numerous as they proceed. The savages of North America esteem it a certain sign that they are near the sea when they find the rivers winding. and every now and then changing their direction. And this is even now becoine an indication to the Europeans themselves, in their journies through those trackless forests. As these turns of the river increase as it approaches the sea, it is not to be wondered at that they soinetimes divide, and thus disembogue by different channels. The Danube empties itself into the Black sea by seven mouths; the Nile into the mediterranean by seven, and the great river Wolga into the Caspian by seventy Buffon
says, that the current of rivers is to be estimated very different from the manner in which those writers who have given us mathematical theories on this subject, have represented. They found their calculations upon the surface being a perfect plane, from one bank to the other ; but this is not the actual state of Nature in this case ; for rivers in general. rise in the middle; and this convexity is according to the rapidity of the stream. Any person, to be convinced of this, need only lay his eye as nearly as he can on a level with the streain, and, looking across to the opposite bank, he will perceive the river in the unidst to be elevated considerably above what it is at the edge. This rising in some rivers is often found to be three feet high. To account for this it is supposed the water in the midst of the current loses a part of its weight, by the velocity of its motion; while that at the sides, by its slowness, keeps its natural level. It sometimes happens, however, that this appearance is reversed; for when tides are found to flow up with violence against the current, the greatest rapidity is then found at the sides of the river, as the water there least resists the influx from the sea. On these occasions the river presents a concave rather than a convex surface; and, as in the former case, the middle waters rose in a ridge, in this case they sink in a furrow.
TO BE CONTINUED.
DIVINE JUSTICE CONSIDERED.
Extract of a Letter to the Author of “ Letters on the Religion
Essential to Man."
ALL men are in their own minds convinced, or if you will, persuaded
of thig, ruth; viz. that unjust men cannot finally escape unpunished. to this they confine the idea they have of justice, which they know inore by its effects, than by itself.
It would however greatly concern us to know justice in its origin; we should perhaps find there the solution of a difficulty, which arises here very naturally.
It is said, that truth, goodness, and even justice, require that God should distribute the rewards he has promised; and that he cannot dispense with doing it. But it is asked, whether he could not forbear to punish? whether it is not in his power to shew mercy and pardon the guilty?
To this it is answered, that God is obliged by his justice to execute his threatenings, as well as to fulfil his promises. But is it not evident, that this answer is not satisfactory, and that it is begging the question? for it is allowed to be just, that crimes should be punished. But if God cannot dispense with inflicting punishments, we ask the reason of this necessity ?
I believe, Sir, you will agree with ine, that no satisfactory answer has yet been made to this question.
ANSWER TO THE FOREGOING QUERY.
your remark is very just. Nothing is better known than justice in its most glaring effects, and nothing is less undertood than justice, considered in itself. It may
be said, that it is not necessary for man to know the nature thereof, and that it is sufficient for him not to mistake its effects. This would certa'nly be sufficient, was it not probable, that his being ignorant of the cause, may at last occasion his mistaking the effects of it: this appears from the difficulty you propose which I need not repeat.
Justice may be considered in various respects. We have elsewhere observed, that justice is no more than perfect equity, and that equity signifies equality or proportion. This way of considering it is the easiest, and the nearest : at the same time, it is founded upon truth; and if men always considered it in this light, they would not conceive a false notion of it.
Let us endeavour to trace the thing a little higher, and consider what justice is essentially, or what can be the cause of it. Let us first observe, that it is an essential property of a wise being to do nothing in vain From thence we may conclude, that the Author of nature must have designed thc different faculties with which he has endowed man for different uses, which concur in perfecting the whole: we may likewise conclude, that when the faculties are applied to other uses, order is thereby overturned, and still more so, when they are the noblest faculties of the mind which are misapplied.
A comparison will not be improper here. The human body is so framed, that all the parts of it have their several uses; their order and the subserviency of them to each other, bears a relation to these uses. This order is essential, not only to the beauty, but likewise to the well being of the body; and as soon as this order suffers any change, that well being ceases; there arises a painful sentiment, which is a certain sign that some of the parts are disordered. From, hence it is easy to conclude, that pain is only a consequence
of disorder. Methinks it might likewise be concluded, that disorder cannot be introduced into the faculties of the mind, without raising in it a painful sentiment.
Upon taking a nearer view of this inatter, we shall find that if it was otherwise all nature would be destroyed.
Let us suppose that well being is not the consequence of order, and that pain does not proceed from disorder; how should we know when the disorder begins, or be induced to employ the means of preventing the progress of it?
Nay, further, without the connection that subsists between pain and disorder, men could not discern the difference between order and disorder; nothing would induce him to prefer one to the other.
It is objected, that the beauty of one, and the deformity of the other, would be sufficient to determine his choice; I answer that the first, the invincible desire which appears in man is after well being; that without the relish he has for what is good, he could have none for what is beautiful.
In effect, the first perception which man has of what is beautiful, and what is deformed is only the agrecable or disagreeable impression which things make upon him; and the preference he gives to what is beautiful, is only the effect of that impression.
From hence I conclude, that man does not perceive the cessation of order, but in proportion as he feels the cessation of well being.
Let us return to the idea of justice; and remove the idea of rigour which is annexed to it. If we suppose that order only prevails among the creatures this rigour' would not take place.
In this case justice would be essentially nothing but order itself, and that exact proportion which constitutes the harmony of order, as it does the perfection and happiness of intelligent creatures. Or if you would consider the matter otherwise, justice in God will be the approbation he gives to that order, and the delight he takes in the happiness and perfection of the beings whom he has created,
Let us now suppose, that disorder prevails among the creatures, what will follow from that which we have laid down concerning the nature of justice? Order and harmony ceasing, pain and confusion will be the consequences, the natural and inevitable consequences of it.
And if we go back still farther, and consider what justice may be in God, we shall find that it is invariably the same, as we have supposed it; the same, I say, in its principle.This principle is the good will