In the transportation of milk to market and its delivery to consumers, much of it is badly injured, especially in hot weather, by the breaking of the butter vesicles, so that the fluid is in an intermediate state between pure fresh milk and butter. This is occasioned by the jolting to which it is subjected, an operation analogous to churning. It is evident, therefore, if the milk can be kept motionless it would be as fresh at the end of its journey as when first put into the can. In the device herewith illustrated this is very ingeneously accomplished. In place of the usual stopple, or cover, there is put on the can, A, a cylindrical cap, B, that is secured to the top of the can by means of hooks, as seen;, or any similar device, a joint being made by a rubber ring seated in the cylinder. In the center of the cap is a tube, C,closed at the top by a cap, D, fastened with snugs and inclined channels similar to the method for securing the lamp in an ordinary lantern. This tube is open at the ends, forming direct communication with the interior of the can. A piston, E, fits closely the interior of the cylinder and the exterior of the pipe and is kjspt down by a spiral spring inside the cylinder. When the can is filled, the cylinder is secured to the can and then milk enough poured into the tube, C, to fill it to the top. The bottom of the piston bears on the surface of the milk and the spring resists the tendency of the milk, when jolted to move. The utility of the improvement is evident. Patent pending through the Scientific American Patent Agency. Further particulars may be obtained by addressing J. M. Burghardt, Great Barrington, Mass. Patent Office Decisions. Commissioner Fisher has given his decision in the interference case between the applications of S. M. Clark, late of the printing division of the Treasury, and A. C. Fletcher, of New York city. The only question to be decided was that of priority of invention, both of the parties having invented a self-canceling stamp, and, so far as any evidence is shown, without any knowledge of the other's labors. He has also given his opinion in the interference case of White and Purdy for a box opener, giving the patent to White. In this case two neighbors claim to be the original inventors of the same tool. Arguments on the celebrated Harmann and Gilmore millstone dressing machine interference case was heard on Tuesday, the 18th of May. This is a very interesting case, and has excited considerable attention from inventors and others interested in patents ; not so much on account of the direct interest as upon the side issues incidentally involved. In 1863, or thereabout, John T. Gilmore, of Painesville, Ohio, obtained a patent for his machine, but did not push its introduction to any great extent. In 1867, one Gooley applied for and obtained throtfgh some oversight of the office a patent for precisely the same thing. The patent, upon coming before the courts, was set aside by Judge Olin, a year or two since. Before the issue was made, Gooley had sold his patent to> a gentleman from London for $130,000, and $40,000 had been paid upon it. In order to make himself whole in the matter this gentleman induced Hermann, a Frenchman, to apply for a patent in this country for his French patent taken out in France in 1854. Some changes were made in the machine, and in its new form it was submitted to the Office for a patent* An interference was declared, and the case came before Commissioner Fisher upon a question of priority of invention, and a claim that the machine patented by Harmann and that by Gilmore were unlike. Without closely scrutinizing the other questions, the Commissioner rejected the application of Harmann on the ground that his invention was in " public and common use " in this country prior to his application for a patent from the United States. Upon the appeal of S. W. Ad wen, of Rochester, N. Y., who applied for a patent for a mode of baling hay and straw, Commissioner Fisher has reversed the decision of the Board of Examiners, and ordered a patent to be issued. Telegraph Lines and the Aurora Borealis. Mr. George B. Prescott, well-known as an electrician and author of valuable works on the telegraph, makes the following interesting explanation of a phenomenon noted in the case of the recent auroral display: " On the evening of the loth of April a magnetic storm of unusual force prevailed over the entire northern section of the country, which so seriously affected the operation of the wires that, on some circuits, they could only be worked by taking off the batteries and employing the auroral current instead. The effect of this great disturbance of the earth's magnetism was manifested with particular power upon the wires between New York and Boston, and for several hours the lines upon this route depended entirely upon this abnormal power for their working current. During the prevalence of this storm, however, I operated upon two wires between the above cities by a plan which rendered them as free from the effects of these earth currents as a local circuit. Every one has observed that the auroral current comes in waves of ever-changing polarity, corresponding in length and direction with the scintillations of the visible aurora. Sometimes these waves continue but a few seconds, and sometimes for a longer time, but their constant change of polarity prevents the successful operation of a wire, because at one moment the auroral wave may augment the strength of current on the line, while at the next it entirely neutralizes it. Therefore, it has frequently been found advisable to remove the batteries entirely and work with the auroral current alone. But the operation of the lines in this manner is very unsatisfactory, owing to the uncertain and fitful character of this force; and, therefore, any feasible plan by which the wires may be worked under such circumstances*is worthy of adoption. " The plan by which I overcome the difficulties arising from the disturbance of the earth's magnetism was by disconnecting two wires from the earth at Boston, and connecting them together, while I grounded them both at New York, thus forming a loop extending from New York to Boston. As the two wires were both upon the same supports, the auroral wave traveled over ach in the same direction, and, by uniting the two wires at one end, the auroral influence upon one wire was made to neutralize that upon the other, and thus the wires were left entiraiyfree. " Of course it makes no, M r ce'it# r 'often the polarity of the auroral current ehangV-'Q-'tlie strength of this current may vary, since the direction of the current, and its strength, change as much upon one wire as the other, and therefore the current upon one always exactly equals and neutralizes the other." Recipes for Colored Potters' Glazings. WHITE GLAZING.—Prepare an intimate mixture of four parts of massicot, two parts of tin ashes, three fragments of crystal glass, and one-half part of sea salt. The mixture is suffered to melt in earthen-ware vessels, when the liquid flux may be made use of. YELLOW GLAZING.—Take equal parts of massicot, red lefLd, and sulphuret of antimony. Calcine the mixture and reduce it again to powder, add then two parts of pure sand, and ones and a-half parts of salt. Melt the whole. GREEN GLAZING.—Two parts of sand, three parts massicot, one part of salt and copper scales, according to the shade to be produced. The mixture is melted as directed above, VIOLET GLAZING.—One part of massicot, three parts of sand one of smalt, and one-eighth part of black oxide of manganese. BLUE GLAZING.—White sand and massicot, equal parts, one-third part of blue smalt. BLACK GLAZING.—Two parts of black oxide of manganese, one of smalt, one and a-half of burned quartz, and one and a-half of massicot. BROWN GLAZING.—One part of fragments of green bottle glass, one of manganese, and two parts of lead glass. The Phelan Prize Billiard Cue. We have had the gratification of personally examining this cue, with which the public have been made more or less acquainted through the daily press, and which was won by Mr. John Deery, at the grand billiard tournament held in this city and closing on May 10th. It is valued at $600, and was designed by Mr. Phelan, of the firm of Phelan & Collender, billiard table manufacturers in this city, and is a very beautiful piece of workmanship. It is of ivory, tipped by a large and beautiful diamond, with handle mounted with gold, mother-of-pearl, and valuable jewels. The fortunate winner will be more fortunate still if he succeeds in keeping it against all contestants. THE underground railroad bill has been revivified by the Legislature. The charter is in the hands of responsible men and we trust that this important work may be carried forward without delay. The corporators are allowed two years to begin the construction of the tunnel, and are to have three years thereafter in which to complete it to the Harlem River. The Materials of the Universe. A great part of the magnificence of spectrum analysis consists in the extent of its application. Not bounded by the system to which we belong, it carries out its gaze to the utmost limit where light is manifested in sufficient quantity to be comprehended in its grasp. And therefore it would only be a natural consequence of our achievement in solar discovery that those remoter strongholds of mystery should be assailed in turn. Too much, of course, ought not to be expected in the result of a proceeding of such extreme delicacy, and requiring such intense exertion of vision. We have to deal with no glowiiig disk, no golden shield displaying at once its blazonry but with points, which the highest effort of the most powerful telescope can invest with no true dimensions ; whose apparent magnitude is but an illusion—where light is all. But that light, because it is light, shall be made to tell us of its origin ; and if it speaks but in a whisper, that whisper shall bear an interpretation of wonder. And what is that interpretation ? It will not lead us to " doubt that the stars are fire," flaming with intrinsic, not visible by reflected light; for their mere aspect, combined with their extreme apparent minuteness, has already excluded that doubt. It will not announce to us as a discovery that they are suns ; for such would be the natural inference of any one who considered that, at a sufficient distance from the eye, our sun must necessarily be dwarfed into a star. But it will tell us this fact, utterly undemonstrable in any other way, that those suns are so far identical in chemical constitution with our own, that they have the spectrum of solid or fluid incandescence, interrupted by the Mrs of developed and reabsorbed light given out by volatilized elementary matter—that they are so far similar as to contain many of the same elementary lines—that they are so far dissimilar as to exhibit bands corresponding neither with solar nor terrestrial elements and indicating materials utterly unknown and inconceivable. That interpretation tells us, too, how in certain stars the incandescent gases seem to give out their brilliant lines unreversed by traversing a cooler external shell; and how, in one case at least, a temporary blazing out of light depended upon an actual ignition of a vast volumeof hydrogen ; it was for the time " a star on fire." Nor is that all. There are, irregularly dispersed throughout the heavens, small patches of a misty aspect, a great proportion of which are proved by the use of powerful telescopes to consist of densely compacted aggregations of extremely minute stars; while others, by their obstinate resistance to this mode of analysis, and the " milky," or to use an artist's term, " sponged out" character of their light indicate some other constitution. Little had that constitution been suspected before the spectroscope of Huggins applied the decisivetest. Longago, indeed, the bold speculations of Sir W. Herschel and Laplace had ascribed td them the combination of mist and fire, and viewed in them the embryo state of future suns and their dependent planetary systems—an hypothesis as captivating to the imagination of some, as unsatisfactory to the mental habits of others. But, whether acceptable or displeasing, this is not so. At a subequent epoch, indeed, that " nebular theory " had been viewed,with less favour, in consequence of the overstraining of a plausible" analogy. So many of these cloudy masses, once deemed " irresolvable," had given way before the recent increase of optical power, that it was not unreasonably inferred that instrumental deficiency alone prevented a similar analysis in every case. Yet appearances were occasionally against that inference, and this time appearances were right. The spectroscope has taken up the investigation where the telescope could carry it on no longer, and pronounces the nature of many of those bodies to be truly that of a fiery mist, composed, however, not, as had been fancied, of all the uncon-densed materials of a future sun and planets, but of a very few gaseous elements, whose insulation in space and incandescent condition, can never cease to be a source of amazement.—Wra- eer's Magazine. The Power of Attention. In proportion to a man's power of attention will be the success with whicli his labor is rewarded. All commencement is difficult, and this is more especially true of intellectual effort. When we turn for the first time our view upon any given object, a hundred other things still retain possession of our thoughts. Our imagination and our memory, to which we must resort for materials with which to illustrate and enliven our new study, accord us their aid unwillingly, indeed, only by compulsion. But if we are vigorous enough to pursue our course in spite of obstacles, every step as we advance will be found easier, the mind becomes more animated and energetic, the distractions gradually diminish, the attention is more exclusively concentrated upon its object, the kindre'd ideas flow with greater freedom and abundance, and afford an easier selection of what is suitable for illustration. And so the difference between an ordinary mind and the mind of Newtoa consists principally in this, that the one is capable of a more continuous attention than the other—that a Newton is able, without fatigue, to connect inference with inference in one long series toward a determinate end ; while the man of inferior capacity is soon obliged to break or let fall the thread which he has begun to spin. This is, in fact, what Sir Isaac, with equal modesty and fhrewdness, himself admitted. To one who complimented him on his genius, he replied that if he had made any discoveries it was owing more to patient attention than to any other talent. Like Newton, Descartes also arrogated nothing to the force of his intellect; what he had accomplished more than other men, he attributed to the superiority of his method. Nay, genius itself has been analyzed by the shrewdest observers into a higher capacity of attention. " Genius," says Helvetius, " is nothing but a continued attention." " Genius," says Buff on, " is only a protracted patience." " In the exact sciences, at least," says Cuvier, " it is the patience of a sound intellect, when invincible, which truly constitutes genius." And Chesterfield has also observed that " the power of applying an attention, steady and undissipated, to a single object, is the sure mark of a superior genius."—Sir William Hamilton. Important Experiments with Heavy Guns. The London Times gives the following interesting summary of the results of recent experiments with heavy guns at Woolwich: " One pattern of the Woolwich coiled wrought-iron gun endured 400 rounds with ordinary service charges of 30 pounds, English large-grain cannon powder, and 714 rounds with battering charge of 43 pounds ; in all 1,114 rounds—a test far beyond anything that such a gun could probably be called upon to resist even during a great war. The gun remains perfectly serviceable. The gun and its ammunition were calculated for each other, regard being had both to power, endurance, weight and cost; and that there may be no mistake as to the powers of the Woolwich 9-inch gun with battering charges of 43 pounds, we give the maximum penetrations which the gun is capable of effecting, as laid down by the Committee on Fortifications : into earth 40 feet, into concrete 12 feet, into brickwork 12 feet, into rubble masonry 8 feet, massive granite 2 feet (but with fracturing and disintegrating effect to a much greater depth and over a considerable area), into iron plating 11 inches. " The second gun fired 400 rounds with 30-pound charges, and 649 with 43-pound charges—1,049 rounds in all. During the firing of the 400 30-pound charges, and during 207 of the 43-pounds charges, the vent was in rear of the usual place. The last 442 rounds with 43 pounds were fired through a vent, in the ordinary service position, which is more severe upon the gun. The piece is now unserviceable, but became so by a most gradual and easily watched process. About 200 rounds before the end of the trial, a flaw was detected in the steel tube. It developed gradually, though the steel barrel is tightly gripped by the wrought-iron exterior, up to the l,002d round, when gas was discovered escaping from the indicator hole—a small orifice bored in all our heavy guns to give notice when a steel tube is cracked through. The proof was continued with full battering charges, until, at the 1,049th round, the steel tube shifted forward about two inches, and closed the vent, so that further firing became impossible. Thus, though the gun is unserviceable, it has stood an enormous test, and yielded slowly at last, step by step." Spectacles. With most persons, there is an epoch in life when the eyes become slightly flattened. It arises, probably lrom a diminished activity of the secreting vessels. The consequence is that the globe is not kept quite as completely distended with fluids as in youth and middle age. There is thus an elongated axis of vision. A book is held further off to be read. Finally, becoming more flattened by the same inactivity within, the difficulty is met by putting on convex glasses. This is the waning vision of age. If, however, when that advancing imperfection is first realized, the individual persists in the attempt to keep the book in the old focus of vision—even if he reads under perplexing disadvantages, never relaxing, but perseveringly proceeding just as he did when his eyes were in the meridians of their perfection, the slack vessels will at last come up to his assistance, and the original focal distance will be re-established. This statement will unquestionably be combated, energetically, by those who use glasses. But it will be a waste of forensic powder, because the fact is established beyond cavil. We do not pretend it will be successful in every instance ; but generally, if glasses are once resorted to, then the opportunity of doing without them is forever lost. Very aged men may be noticed reading fine print; and ladies, too, by scores, who resisted glasses at the age of life Teferred to who enjoy all the comfort of distinct vision, and they will, until, like the deacon's chaise, every stick in the vehicle falls to pieces at the same time. Therefore, begin with a firm resolution never to use glasses of any kind, for reading or writing. The ancients knew nothing about suoh contrivances ; if they had, there would have been poor eyes in abundance, and oculists to meet the emergency. Cicero never complained of imperfect vision at the age of sixty-three. He even wrote his last letter by torchlight, on the eve of being put to death by the waiting soldiers. Humboldt died at ninety-two, having never been embarrassed with those modern contrivances, lunettes. John Quincy Adams, illustrious for scholarship, at a ripe old age saw without them. Indeed, it would be a laborious enterprise to collect a catalogue of names in the chronicle of literary fame, of men and women, who were independent of glasses.—Dr. J. V. G. Smith. Patents. Those wishing to secure patents can save themselves much time and trouble by applying direct to Munn & Co., of New York. They have now been engaged in this business twenty-five years, and have the most extensive facilities for obtaining patents in the world. Their establishment is literally a patent office of itself, and, as we have had several dealings with them, we can speak advisedly of their promptness in putting through any business intrusted to them. About one-third of the entire number of applications filed at the Patent Office in Washington pass through their hands, and their charges are very reasonable, while they are very accommodating in advising as to the probability of obtaining a patent, where there is any likelihood of infringement, before allowing the applicant to incur any expense. They publish a pamphlet giving full instruction as to the mode of applying for patents, which is sent free by mail; and they are also well known as the editors of SCIENTIFIC AMEKICAN, a paper devoted exclusively to new inventions and scientific subjects, which has had, for many years, a large circulation throughout the United States, and which is recognized as the highest authority on all such subjects. Their corps of specification writers and counselors are made up from the ranks of the Patent Office, and are fully posted as to the merits of new inventions, from practical experience, obtained while examiners there, and they make no charge for advice before receiv ing applications for patents.—Gfaheston Daily News. On the Substitution of Sodium for Phosphorus in Lucifer Matches. Dr. H. Fleck, of Dresden, has instituted a series of experiments with the view to obtain a non-poisonous paste for application to lucif er matches. He ascertained, by some preliminary experiments, that sodium, when minutely divided along with explosive substances, becomes highly inflammable when simply moistened with water. A mixture, constituted according to the formula— (K0,NO5) + Na + 2C=(KO,CO2 + NaO,CO2) + N, formed a grayish-colored mass, which, pn being touched with a moistened glass rod, ignited like gunpowder ; this mixture was, however, found to be unfit to ignite ordinary brimstone matches for a cotton wick soaked in petroleum. In order to mend this defect, black sulphuret of antimony was substituted for the charcoal, according to the formula— 3(KO,NO6) + Na + (SbS3)=Na0,Sb06) + 3(KO,SO3) + 3N, and the mixture made up of— 0'5 grammes of sodium= 4-05 per cent. 66-0 " nitrate of potash =61-39 36'5 " sulphide of antimony . =33'96 Provided that during its manufacture this mixture is kept thoroughly dry, it has been found to answer admirably well. The mode of making it up is briefly as follows : Pure solid paraffine is put into a well-stopped glass flask, and melted over a sand bath ; when fluid, clean pieces of sodium are added, and liquefied under the paraffine. As soon as the metal is thoroughly liquefied, the flas is closed and shaken for about ten minutes, which has the effect of granulating the metal, or rather reducing it to a fine powder. The metal is then poured out of the flask along with the paraffine, and the sodium taken out of the paraffine by means of a clean dry spoon; from 30 to 35 per cent of paraffine remains adhering to the metal; this, however, does not impair its inflammability, while it tends to preserve the metal. Owing to this increase, instead of 5 grammes, 6'6 grammes of the metallic powder thus obtained must be weighed off. The incorporation with the other ingredients, previously well dried and warm, is effected under petroleum in metallic mortars, but each of the substances is first mixed with some petroleum, and pulverized separately before being triturated with the sadium ; instead of gum or glue, caoutchouc, previously soaked in light petroleum oil at 110 deg. C. for ten or twelve hours, is used as mass to foim an adhesive paste with the other materials. According to several accounts from Germany, this plan of substituting sodium for phosphorus has been favorably taken up by some of the largest and leading manufacturers of lucif er and fusee matches. There is saidto be not the least danger in the transport.—Devtsclie Industrie Zeitung. Ocean Telegraphy. Ocean telegraphy, says Morgan's Trade Journal, has made good progress. Before the end of the summer we shall, in all probability, have another transatlantic cable laid—the one from Brest to the French island of St. Pierre, and then on to a convenient landing place on the coast of the United States, not far from Boston. Again, a project to extend telegraphic communication from Cuba (already in connection with Florida) by Porto Rico through the West India Island, is favorably entertained. Prussia, too, we hear, is beginning to think of securing more direct communication with America. It has been suggested that if a cable were laid from a point on her seaboard round by the north of Scotland and by the western shore of Ireland, to join the Anglo-American cables at Valen-tia, Prussia would send all the North of Europe messages by this route. It is understood that the Prussian Government have had the subject recently before them, and that a concession has been granted to carry out an Atlantic cable, having North Germany for its termini. The old project of the North Atlantic is being again mooted. That route was to go by Iceland, Greenland, and so on to Canada and the United States, Denmark being the assumed starting point. The cable to India by the Red Sea is going on satisfactorily, and an auxiliary line—one between Marseilles and Malta—is spoken of. All these projects indicate increased convenience and gain to the public. At present the use of the ocean telegraph is confined to the commercial community ; but ere long, when the tariff is reduced from Europe to America and to India, the general public will send messages as freely as they do by the land wires. We may reasonably hope, too, that the cost of submarine cables will be reduced by-and-by, and this will do more to cheapen messages than anything else. Gutta-percha and india-rubber have had a very good time of it. Can we not get some other material, natural or artificial, that will well as either of them ? DEODOBIZEB FOB EAKTH CLOSETS.—J. S. Kelly, of White Plains, N. Y., notices approvingly our article upon the value of earth closets, and considers it a subject of great importance. Mr. Kelly recommends dried peat as the most powerful absorbent of decomposing organic matter. Being composed entirely of vegetable matter it takes up the ammomacal vapors,' whicli cannot be thoroughly done by earth.