The Control of the Mississippi To the Editor of the SCIENTIFIC AMERICAN: Some features of the editorial, The Problem of the Mississippi River, in the SCIENTIFIC AMERICAN of February 15th, should be discussed from all viewpoints, for of course the subject is so important that there cannot be too much light or sincere thought thrown upon it. In the editorial this statement appears: As a matter of fact, what takes place is this; when the floods come down, the deep pools are scoured out and the material is deposited on the shoals farther down the river, causing a temporary raising of the bottom at these points. As the river falls, the action is reversed, the bars are scoured out and the sand is deposited in the next pool. Careful surveys for several decades show that not only has there been no raising of the river bed, but the cross section has slightly increased. Please observe: Col. Suter considered it safe to assume that fully 400,000,000 cubic yards of material came out of the Missouri River in twelve months. (P. 47, Report by a Select Board of Engineers on Survey of the Mississippi River, Document No. 50, 61st Congress, 1st Session, H. R.) Other observations indicate an outflow of sediment and rolling material of about 36,000,000 cubic yards per year from the Ohio River, about 5,000,000 cubic yards from the Arkansas River, and about 6,000,000 cubic yards per year from the Red River. (The same page.) That is to say, our best authorities indicate 447,000,000 cubic yards of material projected into the lower Mississippi, taking no account of the discharge of material from such streams as the St. Francis, Yazoo, White, Hatchie, Obion, Kaskaskia, upper Mississippi, and countless minor tributaries. The Mississippi discharges into the Gulf of Mexico a possible 300,000,000 cubic yards, which leaves 150,000,-000 cubic yards at least to dispose of between the levees annually. Light sediment is washed on into the Gulf; behind it follows the vast river of gravel and sand, filling in between the levees as you may have observed, say at what is left of Island No. 10, just above New Madrid, and say at Wolf Island and Plumb Point Reach and other points, with diminishing size of particles down to the almost gritless and horrifying slime of the mud bars in the lower river. Of course, sand does find its way into the Gulf, say 30,000,000 cubic yards. (P. 79, Levees of the Mississippi, Government Printing Office, 1867.) Compare this 30,000,000 cubic yards of heavy material flowing out the passes with the 213,000,000 cubic yards of sand and gravel coming out of the Missouri alone (p. 47, Doc. No. 50, above referred to) and it seems clear that the position of the SCIENTIFIC AMERICAN is not according to the facts with regard to the grave question of the cross section between the levees of this day and to come. Indeed, in view of the geological history of the Mississippi bottoms, I am not a little surprised to see a position taken that is so clearly and easily demonstrated as untenable. Of course, in taking this position, the authorities consulted were mere testimony before sundry and divers committees, and not the original documents containing the figures; at least so it seems to me after carefully considering the deductions, without knowing from what data they were made. The Mississippi bottoms are largely alluvial, and the physical conditions have not changed at the behest of the hopes and desires of those who demand the maintenance of the ordinary levee projects in the Mississippi bottoms. Of course, the question of profit is one for mathematicians to answer. If the profit of a levee system, essentially and as a matter of theory wrong, is sufficient to make up for the inevitable disasters due to topping the levees at some nearer or farther date in the future, very well; but we should not enter upon a vast expenditure blindly and with ostrich neglect of the fundamental and indisputable fact that the channel inevitably fills. Indeed, provision is already being made for this condition; the levees are being thrown up farther and farther apart, because of rising floods. I need not discuss the cause of these apparently increasing floods, nor the probable increase of the finer sediments due to wash of cut-over lands, etc. Neither is it necessary to remind the Mississippi valley students that between the levees now lies some of the most fertile of Mississippi bottom lands; while as the levees recede from the caving banks and the coiling and creeping waters they ever encroach on the better lands, crowding the cotton and other planters farther back into the swamps. That is to say, millions of acres of land between the levees is utterly wasted under the present method of levees. The minor consideration of the narrow chute between the levees in the lower valley serves to emphasize the comparison to a spillway over a dam, the levees effectually damming the river and ponding the water in the swamps and up the tributaries and main river. The editorial under discussion did not mean, of course, to say that 2,300,000,000 cubic feet per second is the river flow. The annual discharge varies from around 11,000,000,000,000 to 30,000,000,000,000. The per second discharge of 1903 reached 1,777,000 cubic feet. I am experiencing considerable difficulty in getting recent public documents on the subject, there being apparently no catalogue covering so important a matter as public documents relating to the river. I judge, however, that it is claimed that a second flow of 2,300,000 cubic feet has been observed. Now this is 523,000 cubic feet per second more than the previous record of 1,777,000. Before accepting these figures, it is essential that we know whether soundings were made on the date of the flow, or whether the old cross section for the point of observation was used in estimating the flow. The passing of a wave of sand at the time of the measurement would very easily account for the apparent tremendous increase in flow over the previous record. I observed in reports of the flood last spring that the coexisting stages on the Ohio and Mississippi apparently did not indicate any such increase, and I tentatively ascribed the crevasse disasters to the filling of the river bed and to the ponding of the flood by increased length of levees preventing the usual overflow at the outlets of various rivers. I feel certain that the figure of 2,300,000 cubic feet is not accurate. Such a figure would, of course, indicate that the levee system is not to blame for the ominous failure last spring, but the figures should not be accepted without a most searching analysis of the figures from which they were made, the point at which they were made, the circumstances under which they were made, by whom, and, as heretofore remarked, whether or not the cross section or cross sections had been greatly changed, due to local or general fill and scour conditions. It is interesting to observe that the river flow varies from 97,000 to 1,777,000 cubic feet per second at Warrenton, Miss. (Tabulated Results of Discharge Observations, 1905.) I presume that the matter of a settling pond on the Missouri has been considered in connection with the reveting of the lower Mississippi. This would stop the river of gravel and sand which menaces the lower river. In connection with reveting the river banks, on page 2,476, Report of the Chief of Engineers, U. S. Army, 1906, is as delicious a bit of humor as ever appeared in a solemn public document. Speaking of the works in Louisiana Bend, 522 miles below Cairo, on the right bank, it says: The total length of the original work was 15,820 feet, of which about 4,000 at the lower end has been destroyed. About half the remaining work is protected by a large sand bar! There is plenty of frankness and explicit detail in the reports made by the Chief of Engineers, U. S. ?., and a quaint humor is occasionally discernible, especially when the men who know find themselves thwarted by those who don't. Certainly what I have said is not an argument against the proposition to turn the whole Mississippi River project over to the army engineers now digging the Panama Canal. Give them full charge and complete freedom; only let us have a thorough understanding and a clear statement of the matter, without compelling the men who know to resort to such perfectly conscious humor as I have quoted in order to indicate the conditions under which they toil and the constant, if locally profitable, folly imposed upon the country by the piecemeal projects now under way. I need not add that I am open to conviction with regard to any Mississippi River plan or project, only the plan should coincide with figures and facts already a matter of axiomatic record. Little Falls, N. Y. RAYMOND S. SPEARS. The Co-operation of Capitalists and Inventors To the Editor of the SCIENTIFIC AMERICAN: In order to have progress we must invent, and in order to invent experimenting is necessary, and to carry on experiments capital must be available. The greatest handicap of the young American inventor to-day is the lack of capital. It is a well-known fact that there are few real inventors who have means of promoting their inventions, for the sons of the rich never think about designing or inventing any machine to save time and labor, as their minds are employed in seeking ways to spend what they have for pleasure; however, there are exceptions to this rule. A great many persons object to the idea of taking their inventions to men of means for promotion, as many inventors have lost not only their patent rights, but much time and money that was spent in perfecting some useful machine or device by taking it to some unscrupulous party with the object of getting financial aid. There are hundreds of useful and much-needed inventions that never get on the market on account of the inventor not being financially able to place them in the channels of trade, so the patent and invention is dropped and the world never gets any benefit therefrom. What I believe to be the most needed in the United States is co-operation between honest capitalists and competent, reliable, and progressive inventors, with thorough patent laws, in a systematic way that will protect patentees and inventors to the extent that they will have a fair showing. This would do more for the advancement of civilization and progress of our country than all the technical schools combined. Tunnel Hill, Ga. SAMUEL H. KENNEDY. The Neglected Study of Muscular Energy To the Editor of the SCIENTIFIC AMERICAN: Those of us who give much attention to the contents of newspapers and popular periodicals cannot fail to notice that as time goes on the space given over to popular presentations of scientific subjects tends steadily to increase. Not only are we made acquainted with the more easily understandable features of novel inventions and the results of original research, but in addition, general outlines of the probable future course of invention and discovery are common. If inquiry were made, as to what special branch of science is of most vital importance to the human race, preference would probably be given to the study of the human body. Again, if the question were put as to what generalization of modern science has influenced thought in the greatest degree, the law of conservation of energy must surely be mentioned. Having regard to these considerations, is it not remarkable that comparatively little is to be found in print with relation to the conservation of energy and the phenomena of muscular action? References to the expenditure of energy by the human body are abundant; the energy in question being supposed to be derived primarily from food. Consideration of the law of conservation of energy would suggest that the body may sometimes receive energy in the form of mechanical work; as when a weight is lowered gently, or a clenched hand forcibly opened. An elementary knowledge of mechanics must convince us, that muscular action may be divided into two classes, namely, the performance of mechanical work by the muscles, and the performance of mechanical work by some outside force, against the action of the muscles. A little reflection will show that the number of muscular actions falling under the latter classification is not inconsiderable, as might be supposed by some. Whether or no the human body is able to make use of the energy expended upon it, and in what form, would appear to be of vital importance; yet in popular medical literature little reference is to be found to this consideration. Possibly the average person would dismiss this subject with a wave of the hand, remarking that the energy must be turned into heat. Personally I cannot believe that this conclusion would be well founded. F. H. ATKINSON. London, Ontario. The Prone Position for Aviators To the Editor of the SCIENTIFIC AMERICAN : A few words about the Prone Position for Aviators. This idea was first put in use by the Wright brothers, who soon gave it up as unsatisfactory. Lying in a prone position, one cannot exert as much force upon the control levers or detect the traverse tipping of the machine as well as when sitting upright. It would be difficult to design a stream-line body that would give the aviator lying in a prone position an unobstructed view. Planing down from a high altitude the position would be very uncomfortable, as the aviator would be literally standing on his head. But why the prone position, anyway? A well-designed streamline body can be made deep enough to permit the aviator to sit up with only his head protruding, and still not offer undue resistance to the wind. Brookline, Mass. DAVID GBEGG. Astronomical Bulls Again To the Editor of the SCIENTIFIC AMERICAN: Your French Academician and his peasant recall a bull made by two still more famous men. In Act V, Scene I, of Coleridge's translation of Schiller's Wallenstein this passage occurs: that single glimmering yonder Is from Cassiopeia, and therein Is Jupiter. Coleridge has a long footnote on the passage, but finds nothing amiss in it; and if there is any reference anywhere in literature to this particular bull, it has escaped my eye. WILLIAM HERVEY WOODS. Baltimore, Md.