Cotton Picker Wanted. MESSRS, EDITORS :—In your issue of the 8d inst., I noticed a plan for directing the attention of inventors to the perfection of machines generally needed. The idea is good, and if the different sections of the country will make known their several necessities I have no doubt but that we will see valuable acquisitions to the already voluminous catalogues of machinery. The necessities of the South in the way of machinery are many. The statistics of cotton show that we have lost about one half of our labor. The experience of every lioij.est planter shows that there is an increasing yearly diminution of labor which so far as the negro is concerned, must go on so long as he controls the Government and makes his money by going into politics, and holding all the offices. The additional experience of our farmers is, that not more than three bales of cotton can be gathered per hand, there are exceptions to this of course. But I lay down the proposition that three bales per hand are more than the averapre gathered even with the additional labor of the women usually hired during the picking season, and I will sustain the fact by the testimony of every planter in South Carolina, Here then is an urgent necessity for a machine to gather cotton; and to the fortimate inventor, whoever he may be, there are laurels and money brighter and more bountiful than have been reached by mowing machines, or sewing machines, or any other invention since the' days of the saw gin. The South, the North, the world needs, and must have a machine to " pick out " cotton, and until we have it, it is folly to talk of raising a " bale to the acre," etc. I have for three years past raised upon our old plan, more cotton than I gathered with all the additional labor that I could hire. Give us a machine to gather, and we may meet the deficiency of labor in raising, by the use of seed planters and other machinery now used in the cultivation of the plant. But don't let it partake of any of the utter worthlessness of that miserable little tin tube with a-crank atui endless chain, with which we have been humbugged since ite war, V. W. WooDWAKD. Winnsboro, S. C. TUe Coming Boiler. MBSSBS. EDITORS :—After reading the article on Improvements in the Steam Engine (page 361, last volume), I concluded to give you my opinion as to wherein the present system of applying heat to steam boilers is really defective, and in what manner the " coming " steam generator must differ from that now in use. First, let us look at the act of making steam in its simplest hght : We apply heat to a vessel of water.and when the temperature rises to 212 Fah, it is gradually converted into vapor, for, at that degree of heat, the expansive force of the nn-confined particles of water just overcome the pressure of the atmosphere. It is gradually converted into steam, because each atom, as it expands,absorbs a great amount of heat from the surrounding mass of water—the latent heat which is necessary to its existence as steam—and this must be replaced by a continued application of heat from the combu.stion of the fuel so long as the operation is prolonged.- A greater intensity of heat will raise the temperature no higher, but, by more abundantly supplying this " latent heat," will hasten the evaporation. If the latent heat of steam was the saim; as that of water, other conditions remaining the same, as soon as a mass of water reached the boiling point, it would undoubtedly explode with great violence. Now, as steam at 212, while under the pressure of the atmosphere, is not capable of performing work, to make it a power, we must still farther heat it; and not only that, but confine it,in order that we may apply its increased expansive force to useful purposes. To use steam economically would seem to be to apply heat in such a manner that no more water be lieated than necessary to keep up a constant supply of steam; and no more heat be used than is required to maintain the evaporation, and to expand the vapor of water to the desired pressure. In the ordinary boiler (it is more properly called " boiler " than steam generator), a large volume of water is kept constantly far above the boihng point, and, as its radiating surface is necessarily very large, it requires a great amount of heat to maintain it at such a high temperature; remembering this, we can imagine the result if a portion of the boiler gives way, when a great proportion of this water would instantly expand into steam. So much may be said, supposing the water to be absolutely pure, but practically this cannot be. The various saline impurities so common in feed water, increasing its density, the more as its depth increases, are, by continued boiling, deposited as a non-conducting incrustation on the bottom and sides of, and -within the boiler. To remedy this, I would never apply heat to the bottom of a steam generator. As it is not necessary to heat the entire mass of water—the object not be- ing merely to make it " boil," as in cooking—for the sake of safety and of economizing heat, I would, also, not place the fire underneath the steam boiler. Safety and economy cover the whole ground as to the value of a steam generator. Now, as it is imxOTacticable to apply heat directly to the surface of the water, which would be, it seems to me, the nearest way of getting at the theoretical result of the amount of heat used in the evaporation of a certain quantity of water, the nearer we approach this point, in the adaptation of the form of the boiler, and in the mode of applying tlie heat to meet the requirements of the case,not overlooking other important requisites, so much nearer shall we be to the attainment of that greatly-to-be-desircd ne phis ultra of steam generators. After a great deal of study on this subject, I have designed a form of boiler, differing entirely in principle from any that I have seen; and though I by no means say that it is of the same form as that which the steam boiler will ultimately assume, yet, for various reasons, as I shall show, it seems to me to be more nearly perfect in theory than any other description of boiler with which I am acquainted. Fig. 1 shows it in vertical section. The boiler proper, B B, is bell-shaped, spherical in its horizontal section. Fig. 2, O being the outer, and I the inner shell. D is the steam dome in which the flues (only one of which is shown, at F),should expose a large heating surface. The grate, I, is placed considerably above the bottom of the boiler,a space being left entirely around be tween it and the boiler, except at the furnace door, to admit air for the perfect combustion of the fuel. Fig. 2 is a horizontal sectional view at the level of the grate. The water level, L, is at the point of greatest heat; and in practice, the temperature would vary from above 212, at this point, down to perhaps 40 at the bottom of the boiler. As the saline matter became more concentrated, it could be drawn oft as often as desired,with very little loss of heat. Near the bottom, also, the feed-water should be introduced. The form of the boiler shows great strength,which would safely admit of the use of a high pressure; and owing to its shape, also, and the position of the furnace, there could be no unequal expansion. With a safety vah e, I believe, that even if the feed-pump gave out—the fire being undiminished—there would be no grea;t danger of an explosion, for, as the water level depressed, the influence of the fire would grow less and less until the heat would only be expended in gradually expanding the steam, the result of which would not be hazardous. A considerable dcirth of water constantly remaining in the boiler, would prove a great means of safety. Other advantages might be named, such as no foaming; rapidity of making steam after " firing up," owing to the small quantity of water heated at once; ease of noting the hight of water from the temperatures of different hights. Of course, the form might be somewhat modified from that which I give; as, for a very large boiler,or,to suit its location, it could be made oval or oblong, from front to rear, remaining about the same in eross section. As the foregoing is as yet merely an opinion, deduced from the laws of steam, as I understand them, not based on a trial of the principle proposed, I may be somewhat in error. If such is tlio case, please inform me wherein it consists. CALORIC. Montour, N. T. OiKit Patent Kiglits to toe Perpetual MnssE.s. EDITOKS :—In No. 2, current volume, of the SCIENTIFIC AMBEICAN, there is an article from Horace Greeley on the rights of property, and after advocating the protection by law of all property, including copyrights and patents, Mr. G. says, " ' Then why not make patents and copyrights absolute and perpetual ? ' is often asked. I answer : There are no absolute rights of property. The land you bought of Government yesterday may be taken from you for the bed of some highway or railroad to-morrow, and you have no redress. Ml rights of property are held sulwrdinato to the dictates of national well-being, and the Government will batter down or bum to ashes your house if it shall have become (through no fault on your part) a harbor or defense of public enemies, and make you no compensation therefor," Mr, Greeley has dismissed the great question, " Why not make patents and copyrights absolute and perpetual ?" in a very summary manner, for one who usually reasons as closely as he does. Tes, why not make patents'and copyrights absolute and perpetual t And as sacred to the author as any other property ? What is an invention ? What is an original book, or picture, or statue ? Are they not the worlc of the human brains and hands ? Most certainly. And fully recognizing this fact, Mr, Greeley says, " Whenever the laws of my country shall refuse to protect the inventor, they should, in simple consistency, bid the land owner, the bond holder, the merchant, ' take care of yourself and cf all that you call your own,' " Now if the inventor has a right of properly in Iiis invention at all, it must, in the nature of things, be a p-Tpctual right, just as mucli so as the right of the laud owner, the 54 ?bond holder and the merchant to their property, which is the property of their brains and hands. Mr. Greeley does not state tlie question fairly in regard to the right of Government to take private property. The Illustration of the power of Government to " batter down your house," etc., has reference only to time of war, and therefore has no place in this discussion. In every other case, if Government takes land or other private property for a railroad or for public improvements, compensation is made for the same. Neither the first nor the third Napoleon have dared do otherwise with the property of their subjects. Why should not property in patents and copyrights be as sacredly kept under the protection of law as any other product of human brain and labor ? The land owner or the merchant may make a million of dollars in a month; the banker may make it in a week, or either of them in an hour. Does the Government ever presume to say to the merchant, the land owner, or the banker, " You made this money quickly, you may have the use of it seventeen years, and at the end of that time we shall withdraw all protection from you, and anybody may take the fruits of your thought and labor who chooses V The Government never says this to the parties above-named, and why should they say it to the inventor ? The land owner, the merchant, the banker in the case above cited, have got all their money by speculation. They have not necessarily added one iota to the wealth and comfort of the people; nay, it is scarcely possible that they have accumulated this large sum without injury to the welfare of the public generally. I copy the following from a recent paper : " The number of thrashing machines in the United States is about 339,000, and ihey save five per cent more of the grain than the flail. There is, accordingly, a saving by these machines of about ten millions of bushels of grain annually." Here, then, we see a saving of " ten millions of bushels of grain annually," with which bread is made for the people. Can Mr. Greeley point to any speculation in stocks, to any lucky speculation in " corner lots," or to any fortunate result in private mercantile speculations upon the comforts and necessaries of life which saves ten millions of bushels of grain annually (or their equivalent) for the benefit of the people; and which adds this amount of wealth annually to the sum total of the country 1 Yet this large saving is from the use of one invention only. Now in the name of all that is just and right, should not the inventors of these thrashing machines be protected in their property as fully and perpetually as the land speculator, the merchant, the banker, and stock broker 1 It any fogy farmer is fool enough to use the old-fashioned thrashing flail, he is at fuU liberty to do so : and if he uses a thrashing machine, and every year saves hundreds of dollars worth of grain by its use; why, in the name of justice should he not pay something to the inventor, and that too as long as the invention is used, or property of any kind is protected by law 1 No good reason can be given to the contrary. A few weeks since two poor half-starved miners in Australia were standing near a tree. One of them struck his pick a few inches into the earth beneatli it, and lo ! a gold nugget worth some $50,000 was discovered. It was the work of a minute only. They did not even own the land on which the treasure was found. Did the English Government say to these men, " You found this great treasure in a minute, and that on Government land. Others would have found it some time if you had not. You may have th.e benefit of it fourteen years, and after that any body may take it from you who chooses." Of course it would not do to say any such thing. It would strike a blow at the safety of all property. The land owner, the banker, the merchant—all speculators—creating nothing of wealth, and the gold finder also; all these are fully protected by law, and may enjoy the fruits of their good lack, or skillful calculation through life, and bequeath the same to their children. But the inventor whose invention saves ten millions of bushels of grain annually, or whose skill and ingenuity add to the comfort and wealth of the people in a thousand ways, is protected a few years only, and the products of his brains and hands is then taken from him by the people whom he has benefited ! The father of the write.r of this article invented, many years since, stone pipe for conducting water. Twenty-five years the brave old man struggled in vain to bring the public to see its merits and adopt the invention. Poverty and disappointment were all he received. Now this mo5t useful invention is adopted everywhere. The original inventor has long been in his grave; but if his right to his invention had been, as it should be, perpetual, his children at least would have received some benefit from the long years of toil and privation which they shared with their father. This loose recognition of a man's innate and perpetual right to the product of his brains and hands—this talk of the Government " giving !" a man a right to the property which he has created, and which he already possesses, for a " term of years," is the real basis of the conduct of that gang of sneaking thieves who hang around a successful invention, and by their audacious infringements keep the inventor in constant litigation, and it is also the basis of the infamous attempt of Macfie, in the British House of Commons, to abolish all property in patents. G. W. P. Boston, Mass. Biseardcd Nutriment, MESSES. EDITORS :—Immediately beneath the outer surface or skin of every kernel of grain, particularly of wheat, there is a thin layer of very nutritious and valuable matter for the sustenance and health of the animal system. In milling, thi is disenrded M the hull. It coMtitntea about twclto { oersi rf tb.s w3ite maifii' of til htm, and Jg mm'i) umM for iP tTOrnot.iufl, of niitMtif)!!, thftn *te t*tte t" gfftlt evo*?'? into flour. This substance consists of a compound vegetable ferment, together with vegetable casein, analogous in form to the thin pellicle between the shell and the albumen of the egg. This may be readily obtained by infusing bran in cold water, and precipitating with alcohol, or evaporating the water. Its office is to bring the other constituents of the flour taken into the stomach with it, into an appropriate state for assimilation by the organs of nutrition. This substance and linseed meal have been tried with marked success in the case of impaired nutrition, and in diminishing the number of cases of consumption. As a test, a soup was made of two ounces of meal, one of bran, and a quart of water; this was boiled for two hours, and then strained, to which lean beef was added, and the whole made into a soup with vegetables. Under this diet the frequency of consumption greatly diminished among the inmates of the City Hospital. It would seem as if impaired nutrition was really an antecedent to the fell disease. If a dog or other strictly carnivorous animal be fed exclusively upon fine flour bread with only water to drink, it will die of starvation in about three weeks; whereas, if fed upon bran or whole meal bread under precisely similar conditions it will continue to flourish ad infinitum without any apparent diminution of vitality or physical strengtt. H. M. R. Hudson City, N. J. To InTentors"-One TUlng Needed. MESSRS. EDITORS :—In your last number I notice a request from an inventor for suggestions ia relation to what to invent. In the same number is a cut and description of a knitting ma-chinewhich will " do better work than can be done by hand." In a number some time agj was a call for the invention of a small, cheap, household power. Now all of these suggest to me a train of thought. Nearly every farmer in the country raises a few sheep; or, if they do not, they ought to, to the extent of their own mutton at least. Nearly every farmer also has a " family of girls," who have " nothing to do " but to read the Revolution and beg " pa " for a seven-hundred dollar piano. Most of these also have " nothing to wear " but " store clothes," and some, in the Eastern States have but little to eat. Their brothers and' fathers and bachelor uncles (they never take me for one of the latter) wear out a great many pairs of stockings, and would be very grateful for numerous other knit garments, such as drawers and shirts and overvests, and even " coats without a seam," all so comfortable and nice to fit and easy to wear and lasting. All of these might be made in the house/roTO the wool. For a power, a small steam engine of one half-horse power will fill the bill, and in the winter will cost nothing to run, its heat being wanted to warm the house. It need not be larger, boiler and all, than two men can lift about; neither need it bo of complicated construction, or have a very " economical " and therefore unsafe " generator." This can be made to saw its own wood and pump its own water, with some to spare, and do a great deal in the family and animal culinary department. Make it safe, with a large valve and light " poi se," and a large water space above the flues, and it may be intrusted to the boy just commencing on " The Natural Properties of Bodies " to run, as a first-class illustration of his first lesson in physics. Next—and here is what is to be invented—we must have a household yarn factory got up on new principles, or a new adaptation of old ones, to fit the occasion. It seems to me that a corder and spinner, etc., can be made that will do a heap of work, and not be hard to managa I know nothing about their construction, or I think I could send you a sketch of something that would work in a day's study. Let the "experts" plan these out, if old plans will apply on so small a scale; if not, let some original barber (?) like Ark-v,a-!ght give it a shave. Then, with the knitting machines, and a loom for flannels if you wish, let the girls go to work, and stop lolling about. The whole apparatus should not cost more than a piano, and, in my opinion, would be a much better investment as the first one. Let the piano be bought and paid for with the proceeds of the socks, and then can be sung with a clear conscience to its jingling accompaniment— Call me not lazy-bred beggar and bold enough; 'or I have learned both to knit and to sew. But I forget—the SOIENTIPIO AMERICAN is not poetical, but is down even on the " poetry of notions." CHARLES BOYNTON.