The Editors are not responsible for the Opinions expressed by their Correspondents. Origin of the Solar Spots. MESSRS., EDITOES:—I notice in No. 23, current volume of your journal, the . speculations of various persons on the origin and nature of the spots on the surface of the Bun. I have ateo noticed more or less speculation on the subject in different publications for some years past. None of them seems to have resulted in anything reliable or satisfactory. Not being myself fully acquainted with the entire field of scientific iesearch, it is possible that a true and satisfactory expna tion of tWs solar phenomenon may exist ; but judging from the hypothetical character of the speculations offered, and the 'Spirit of inquiry that is yet abroad in the matter, and I!i'emingly unsatbfied, especially among more learned men by far than I am, I am led to believe that a true solution of the problem has not yet been found. Having long noticed and meditated on the various theories presented, 1 am led to offer the following unscientific (it may be) yet to me, plausible theory on the topic, which I have maintained ever since I became acquaint ed with the " nebular theory " of the creation, Il.nd which mWf—and seems to me must—explain the bove phenomenon. My theory is certainly in perfect harmony iv, its principles with the nebular theory of Laplace, now generally accepted as the most plausible ; and though it may not be scientifically written, its force will not be impaired in consequence. The theory I have entertained, and do now, is as follows : According to the nebular theory the sun is what is left of the raw material out of which all the other planets were formed. Allowing that the process of creation is still going on, it is reasonable to presume that the method is the same. It follows then that as the surface of the sun becomes cooled, It contracts, and as it contracts, it becomes condensed, also rendered more opaque, thus obstructing more or less, according to' the extent of such . condensation, the fierce flames and light which emanate from such an intensely heated body as the eun is known to be. You will doubtless ask, if the surface of the sun on becoming more opaque, obstructs the flow of heat and light from the sun to the earth, why, as the cooling and contracting of the sun's surface would probably be uni-fOTm on its entire surface, is not the phenomenon of such cooling and condensation uniform also? Because the surface of the sun must necessarily be constantly subject to violent commotion and upheavings of volcania character, and should a uniform crust be formed, it could not remain intact long, but being burst asunder by the central fires and gases, this opaque matter would be thrown aside, and large vents would be created for the escape of these gases. But being thrown aside it'is not lost for the purpose in view, but must still continue large additions of opaque matter consequent upon the furt1her cooling of the sun ; this matter once cooled must remain so, and increase, and the now very large vents must gradually diminish in size, imtil the condensed matter has so accumulated that its superincumbent weight could not be supported by the central gases, then it would break off and a new planet be fo ; or, in case it did not so break off, the sun would gradually cool down, and in so doing the opaque or solid matter would constantly increase, and the vents constantly diminish, and in time would present the same appearance as that of our earth, allowing for the loss of the influence of a sun shining upon it. The proportionate size of its vents or volcanoes, would some day, far in the future, be aboht the Same as that of the earth at the present time. Granting that this cooling process will ever continue—and the nebular theory is founded on this process—the sun will eventua Ily become as cold as the earth is now, though owing to its size it must consume a longer period in doing so. That another planet will at some future time betlborn of the sun, is more probable than that it will cool down in one large maSS. The probability consists in the fact that the sun is so much larger than any of the other planets already bom of the sun, that there is plenty of material in the sun for several more planets of large size, and there would still be enough left to give the new born planets and the old ones light and heat. In case another planet should break off from the sun, it might possibly affect the earth less than the formation of subsequent ones. Undoubtedly the spots on the sun will Continue to increase, and their effect will be felt on our earth until a new planet is formed, then the light and heat from the central and remaining portion will pass out into space unobstructed, until other accumulations of condensed matter obstruct it again. It is fair to presume that for a limited period our earth would be warmer and lighter after the formation of a new planet, than just before. The unobstructed heat and light from the sun, together with that from the new and uncooled planet, which would probably be nearer to us than the sun, would materially add to the heat received on the surface of the earth. How long it will be before another planet is formed (if more are to be created from the Bun) is of course uncertain. Scientific men are better able to note the increase in size and opaquenes of the spots on the Bun than 1 am, but could the intervals between the formation of other planets by the nebular process be found, the time that must elapse before another will come forth could be ascertained with tolerable certainty. These intervals are subjects worthy of inquiry among scientific men. ' But, in case tlie sun cools down without parting with any more of its material, it is evident, as before mentioned, that the light and heat from it will continue to decrease, that the condensed matter will continue to increase, covering more and more of the sun's surface ; at the same time being continually tossed aad upheaved by the forces within, until sufficient is accumulated to partially resist the expansion of these forces. They will, however, find vent in the weakest point. Constant cooling will increase and strengthen the strong points, and they will gradually encroach on the vents ; the central fires of the sun gradually narrowing down at the same time the central forces growing weaker, their vents, in time will become similar to the vents, or volcanoes, of our earth, though all on a larg'er scale, perhaps. Should the sun retain all it material, and its two antagonistic forces—heat and cold—continue to war with each other, and could we be near enough to see, .what a picture of grandeur, what a scene of magnificence would the struggle present, until one of the mighty warriors should succumb to the more mighty strength of the other, till one shall gradually lose its strength, and the sun's light become fainter and fainter ; its warmth and vigor gradually diminishing until its former mighty influence upon others of the universe is no longer felt. However erroneous these views may seem, or may be, they are more plausible than some I have seen published in your journal, and in various other publications, in regard to the spots on the sun. As this is an age of persistent inquiry and investigation, evtlry theory, however extravagant, or vague, may stimulate inquiry until a correct solution of the problem is obtained. I submit tbe foregoing theory, and though, perhaps, containing scientific errors, yet the principles on which it is based, and with which it harmonizes, are just as plausible as any embraced in the famous nebular theory itself, so generally accepted. C. A. HOPPIN. Worcester, Mass. Ventilate yonr Sewers—A Cheap Deodorizer. MESSES. EDITORS :—1 was much interested reading an article in your paper of 37th November, headed "Veatilate your Sewers." One such article may be of more dirlMlt benefit to a family than all the pages of general news published in a thousand daily papers. It is a serions question of direct application. Axe the majority of low fevers and putrid diseases in cities and villages owing to, or caused by gases arisi ng from sewers, drains, and out-houses? My family physician has traveled through many foreign cities, and his experience corresponds with the article you copied from .the New Trk Medicil JmrmiX. When called to attend a family suffering from any lingering or periodical disease, he at once examines all the waste pipes leading to sewers or vaults, and almost universally finds a local cause, and orders it at once remedied, and so checks the spread of the disease. There is scarcely a family th at would not be directly benefited and made happy by the use of a cheap deodorizing material. Most of the articles used are too expensive or have an unpleasant smell of themselves. Caustic lime or chlorine has a too active effect, liberating a gas thatirritates the lining membranes of the throat and nose, to perhaps are already partially diseased, and the immediate effect is catarrh, asthma, etc. The present ventilation of sewers is only through the pipes and imperfect traps under, and leading up into nr houses, poisoning the inmates. The pipe ventilators separate from the house, and delivering the gas above the houses, would at least reduce the poison and obviate its worst effects. I would saggest that no waste but water be allowed to en-the sewers. In France a clay marl is used for deodorizing the waste matter, and one quart each day answers for an ordinary family. The clay marl can be had near to most of our cities. Here it can be put on to New York Central or New York & Brie cars at five dollars for the tun or 2,000 Ibs. It is composed of about equal parts of alumnia, silica, and calcareous' powder. Pure clay is too plastic, and requires mechanical mixing, while the marl readily dissolves and combines with any acid matter or gas until the whole is converted into a fine mold and valuable fertilizer. Our present outhouses are nuisances most of the time, and can be kept free from all smell at one half the price paid for cleaning, and even made a source of revenue. I have tried the clay marl, and fiud it answers the purpose perfectly. The moment it is touched by acid matter it begins to fry or effervesce until every particle is used, and by its own nature of affinity, bringing every particle of clay in contact with the matter to be deodorized. Stone, or pure lime, or sand marls would not act by their own chemical and mechanical arrangement. Buffalo, N. Y. ' O. COBB. Shoartlng Fish Under Water and Flattening the Bnllets. MESSES. EDITORS :—Some months ago myMlf and a companion were out sporting when we accidentally discovered a school of fish at the bottom of the flmne, at the outlet of a pond. The number of fish in the school was about forty, and they lay as close together as they pcssibly could on the bottom of the flume at a depth of j ust eighteen inches below the surface of the water. We had no fishing tackle with us, and we much desired to capture this prize. Myself and companion had with us each a fine sporting fle, and we were not strangers to the use of the weapon. We had, many times before, killed fish by shooting them under water, but not at so great a depth. At length we concluded to try the effect of- our rifles, and, having first secured the passage of the stream below so that the fish could not escape, we commenced operations by discharging our pieC4'ls directly at the center of the finny tribe. We fired shot after shot, until more than thirty shots had been fired, and, in the mean time, we had only disabled two or three fish, and none of these was struck by bullets. We shot at these fish, sometimes at an angle with the surface oi the water, aud soml.ltimes directly'downward, We were disappointed and laid down our arms and waded into the stream. With the aid of our hands and some skillful engineering, we caught nearly all the fish. It now occurred to me that we had used quite too heavy charges of powder to kill fish at so great a depth under water, and on looking carefully into the water, I discovered several of our bullets lying on the bottom of the flume. I again entered tha water and gathered up six of them, and, to my surprise, I found them all flattened out by striking the surface of the water, very similar to what they would have been had they been shot directly against a rock. The balls we used were elongated ones, with flat points. These balls were flattened the instant they struck the surface of the water. The points of them were upset and driven back toward the butt, and spread out until they were twice the diameter of the butt, and very much resembled a low-crowned hat; while the butt of the ball remained in perfect shape. We now loaded our rifles with just one half the usual charge of powder, and killed the two remaining fish at a depth of twenty-two inches under water, by making two shots at each fish, and one of the fish received a ball directly through him. The next day I went again to the place and killed several more fish, and some of them at a depth of more than two feet under water. I afterwards made a number of experiments by shooting at a target that was placed at the bottom of a large watering tub, eighteen inches under water, and found the average penetration of the balls, in a pine target, to be one half an inch. I also tried round balls, under the same circumstances, and found the penetrations in the target nearly as great, while, at the same time, they went more truly. The ,!uantity of powder used in these experiments was just sixteen grains, which was just one half of the usual quantity used for common sporting purposes. The bore of the rifles used was just 130. The reason that 16 grains of powder would cause the deepest penetration in water was,that this quantity was the greatest that could be used without upsetting the point of the balL I also found that this same quantity of powder for a charge, when shot in the air, only caused a penetration of two and one half inches in a pine target. I also found, in shooting at a target, under water, at an angle of 45 with the surface of the water, that, in order to strike the mark, 1 was obliged to aim under the mark (apparently) at least one inch for every six inch es that the mark was below the surface. This was to compensate for the refraction of the rays of light as they left the surface of the water. I will here remark, that when a fish,or other object, is seen in the water, it is always at a far greater depth than it appears, and, oftentimes, nearly double that amount ; hence,the great difficulty of aiming correctly at a fish in the water. Yet, with a little practice, a rifleman can kill fish, quite often, at a depth of from one to two feet under water. It is not necessary that the fish should be struck by the bullets, for if the ball should pass close by the fish, the violent agitation of the water, caused by the ball, instantly stuns and renders the fish insensible, and it immediately turns over on its back. I send you two samples of bullets, which were shot with full charges of powder. One of these bullets was shot at an angle of about 45 with the surface of the water, and the other was shot directly downward. You will instantly perceive which is which. Every bullet, shot with full charges of powder, was found flattened at precisely the same angle that the bullet touched the surface of the water ; hence, it is plain, that this flattening of th e bullets all takes place at the surface, and before they enter the water at all. Jaffrey, N. H. JOHN S. DuTTON. Letters from Inventors. MESSRS. MUNN & CO., etfeOTe.—I have received my patent, dated Nov. 9, 1869, and I am highly pleased with the way in which the business has been done. The ability which carried it through and the scrupulous care bestowed on its preparation are worthy of praise, and I will gladly intrust to your hands any further business I may have to do. 1 remain, very truly yours, SAMUEL BONSER Dover, N. H., Nov. 15,1869. GewtleTOe :—I have j ust received my patent, and I am very much pleased with your promptitude in securing it. I can assure you that any of my friends who contemplate taking out patents—if I have any influence—will take them out through your Agency. Eespectfully yours, Middletown, Ind., Nov. 23, 1869. J. .RWE. Gentlemen :—1'have just arrived home after being absent for some time. Permit me to express my gratification in being so fortunate as to obtain your professional services in securing my patent. For the prompt and highly satisfactory manner in which you have conducted my business at the Patent Office, please accept my thanks. I cannot too h ighly commend your mode of doing busiaess to any one who may need your services. Yours very truly, DAVID P. STEWART. Spruce Creek, Pa., Nov. 27,1869. entlemen :—The letters patent on my animal trap . are received. You will please accjpt my thanks for the prompt, gentlemanly, and satisfactory manner in which the business has been accomplished through your Agency. I have examined the claims thoroughly, and could not add or take away a single word to make them better. Very respectfully yours, C. G. FBUSHOUE, Lagro, Ind., Oct 39, 1869.