We conclude our review of these interesting experiments from our last issue Mr Tomlinson asserts that there is a kind of matter whih when used for nuclei in boiling is not liable to the defects enumerated in our previous article, and which he has not been able to make inactive, either by the action of the strongest acids or caustic alkalies, or by repeated boiling in water, ether, alcohol, naphtha, etc These bodies are such as charcoal, coke, pumicestone, meerschaum, and a few other bodies They act by means of the powerful force of capillarity The same force which, according to Saussure, enables one volume of boxwood charcoal to absorb 90 volumes of ammoniacal gas, 85 of hydrochloric acid gas, 65 of sulphurous acid gas, and so on, enables these porous bodies to absorb vapor from boiling liquids, and, under the continued action of the heat, to give it out in neverceasing jets, thus relieving the vessel ol all tendency to bumping, making the boiling soft, gentle, and regular, and increasing the quantity of the distillate Charcoal, or some other porous body, is then the proper nucleus in the case of boiling liquids It is quite remarkable to see how efficiently a lump of coke acts in a vessel of boiling water in giving off vapor, promoting tranquil boiling, and preventing the jumping of the vessel Not the least important service of these porous nuclei is the fixity they confer on the boiling point When a liquid is boiling in a clean vessel, and in the absence of nuclei, it may go on dissolving steam until the liquid becomes more and more highly saturated with it, and during this period the phenomena of boiling cease, and the temperature rises some degrees above the boiling point % The formation of a steam in liquid is indicated by a rise, the bursting oi a bubble by a fall The most considerable rise and fall is when the boiling ceases and steam accumulates, and there is a sudden burst accompanied by a kicking of the vessel This uneasy kind of action, so manifest on a small scale, must be a mighty force in a steam boiler, or a large still or retort The following series of experiments show clearly the value and superiority of porous nuclei: X A glass flask with a wide neck was filled about one third with distilled water; it was boiled over a gas burner, weighed rapidly, and replaced over the burner After boiling 20 minutes it was weighed again The flask was once more filled to the original quantity, and some bits of coke were added ; it was boiled and weighed as before, the gas flame remaining unaltered all the time RESULTSWater boiled away in the first trial (water only) 995 grains; in the second trial (witli coke) 1,130 grains Ratio ol products, 100: 1136 2 Water was made to distil freely from a still, and the quantity collected in 15 minutes was weighed A few pieces of coke were then added to the water in the still, and the distillate collected again during 15 minutes RESULTSDistillate from water only 293 grains; from water with coke 310 grains Ratio of products as 100 :105'8 3 A similar trial was made with common wood charcoal, but the vessel having been made much cleaner by the action of the first boiling, the water boiled irregularly, with bumping The addition of the charcoal made the boiling tranquil and regular RESULTSDistillate from water only, 262 grains; from water with charcoal, 334 grains Ratio of results as 100: 127'4 The following results are from my own experiments: Methylated spirit was distilled in a glass retort at a fixed boiling point of 171 Fah The distillate collected in 5 minutes was weighed, and found to amount to 244 grains Three or four fragments of charcoal, partly from boxwood and partly from cocoanut sheel, weighing altogether 20 grams, were now added to the retort, and when the spirit was again fairly boiling, the distillate during 5 minutes was again collected and weighed It was found to amount to 325 grains The ratio of the results is as 100: 132'2 Instead of charcoal, 20 grains of fine ground pumicestone in four fragments were used in the retort, when the ratio of results was as 100 : 1217 With 20 grains of meerschaum, as 100 : 112 With 20 grams of coke, as 100: 107'46 These numerical results are, however, very much understated if compared with those obtained in a retort that is structurally free from nuclei, which was by no means the case with the retort actually employed Charcoal, coke, pumice, and other porous bodies are especially valuable in distilling those liquids that are of such a nature as to exert a powerful action in cleaning the inner surface of the retort or of the still Such liquids ag alcohol or spirits of wine, ether, naphtha, benzole, sulphuric acid, etc, act in this way, and the sides of the vessel no longer performing the useful I unctions of a nucleus, the adhesion of the liquid to the sides of the vessel is so strong that the vapor accumulates in it, and only escapes in explosive bursts, separated by almost quiet intervals These porous nuclei render the boiling and the liberation of vapor quite easy Even in thick sirup of sugar, boiling at 240 Fah, they are still active, and Mr Tomlinson asserts that with their assistance he has, in the course of a few minutes, driven off BO much wa ter from a sirup boiling at 218, that it soon reached 240 , and cooled down into a clear, semisolid mass in a flask, into which a plug of cotton wool was inserted when the lamp was removed Charcoal from cocoanut shell is a good nucleus It is very dense, and will occupy the bottom of the vessel that contains liquids somewhat denser than water It is at the bottom, or near the bottom of the vessel, that the nucleus is most efficient, and for dense liquids the porous nucleus may be loaded with some heavy metal that the liquid does not act on Coke, though a lees powerful nucleus than charcoal, is convenient from its being always at hand, and presenting itself in lumps of any size Mr Tomlinson has no doubt it will be found of use in steam boilers, and may be used instead of the radicles of barley, the soap, the butter, and the paraffine, etc, noticed in our last He has already said that these porous nuclei act by the force of capillarity, and so powerful is this force alone that it can be applied in a variety of ways Even a short bundle of fine capillary fibers, united like a faggot by a thread in the middle, is an active nucleus in liberating vapor Such a bundle, weighing only ten grams, put into a retort from which methylated spirit was being distilled, raised the amount of distillate in the ratio of 100 : 110 Where circumstances admit of it, we may apparently increase the nucleus power even of charcoal by first boiling it in a liquid of higher boiling point than that of the liquid to which it is to le transferred Thus a piece of charcoal that has been used in boiling turpentine seemed to be more active than pure charcoal hi liberating vapor from boiling water The charcoal is not only porous, but unclean, and hence its activity What Mr Tomlinson claims to have discovered is the action of nuclei in liberating gas, or salt, or vapor from solution, and the behavior and proper application of nuclei in various processes in the useful arts Bodies have long been used for promoting vaporization, crystallization, etc, but how they acted and why they often suddenly ceased to act was not known We have many theories about the " mysterious action of air," " catalytic action," " molecular change," etc, which have borne no fruit; whereas, according to this view, supported as it is by hundreds of experiments, all the varied phenomena of nuclei may be explained by the varying force of adhesion and capillary action Signaling on Board the Cable Fleet The London Gazette gives the following interesting description of the manner of signaling through the cable on board the Great Eastern: The method of signaling used between the ship and the land is that now universally adopted in working all long submarine linesthe reflecting galvanometer The principle of this most delicate instrument was discovered a few years since by a German electrician, named Weber It was then, however, a large machine, and the condensation of all its powers into the smallest and lightest form is due to the scientific research and skill of Sir William Thompson This instrument consists of a small mirror with a magnet on its back That the two are very small indeed may bo judged by the fact that both together weigh less than three eighths of a grain This infinitesimally small reflector, which is intensely bright, is suspended by a silk thread as fine as a hair in the midst of a small circular coil of insulated copper wires Directly a current is sent through this circular coil, no matter how slight, it induces another electric current within its circle, which acts in an opposite direction, and this causes the magnet at the back of the mirror to turn to the right or left, and, of course, to turn the little mirror with its reflecting ray of light with it By a very simple arrangement, this fine ray of light is thrown upon a horizontal graduated scale, about three feet long and three feet distant from the mirror Thus when a current is sent through the little circular coil around the mirror, the magnet is acted upon, and turns the mirror with its ray of light, say on the left of the scale in front of it When the current is reversed, and that is instantly done by pressing a little key in the speaking instrument, the current in the circular coil is reversed and sent in the opposite direction, and this in turn sends the ray of light from the mirror on to the opposite side of the scale to the right When the ray of light rests stationary on any part of the scale, it means a dot; when it moves rapidly to the right or left, it means so many dashes, according to the distance it goes This reflecting galvanometer tells with unerring certainty whether or not the Great Eastern is steady The vessel now at the end of the cable is, with its coils of insulated wire and iron hull, a mere electromagnot so to speak The course of the Great Eastern is east and west, and therefore at right angles with the course of the magnetic current, which is north and south Thus every time the ship rolls, either to port or starboard, a slight current, but still a current, is induced in her vast coils, and then transmitted through the cable to the shore end at Minou, where it acts upon the reflecting galvanometer, and turns its ray of light a little to the right or left of the center of the scale, and thus shows in a fraction of a second of time the precise degree and rapidity at which the vessel is rolling WE recently noticed the fact that a flying machine was soon to start from San Francisco on its aerial voyage to New York It now turns out that we are to be disappointed, the thing being only a partial success It will navigate the air in a calm, but the slightest breeze disconcerts its movements The Chronicle thinks that if the inventor should ever start for New York, he would be quite as likely to bring up at Cape Horn or the North Pole Gin Saw On in iner The inventor of this instrument claims that whatever injury cotton sustains in its separation from the seed, is caused by the action of the saws in concert with the ribs of the cotton gin While this will be generally admitted, there is a diversity of opinion in regard to the character of the teeth as to form and surface It has been the theory and practice of gin makers to make the gin saw teeth as round and smooth as possible, in order that they may go into the cotton and not cut the fiber, as they assert would be the case with a square tooth The inventor of the gin saw gummer shown in the engraving, who has had a long ex perience in the working of gins, affirms that neither round nor square teeth cut the cotton fiber, but both break it, and he affirms that square rough teeth will, on a fifty saw gin, pick a bale a day more than the round smooth teeth He claims that the notion that a gin which picks rapidly must, of necessity, injure the fiber, is totally erroneous The gin saw gummer is an instrument devised for the purpose of giving each tooth of a gin saw the proper roughness and form We say proper roughness, because if the principles above stated are correct, it does not follow that any kind of roughness will answer the purpose It is claimed that the circular fi!e of the form, and used in the manner shown, in the engraving, is the only tool that will secure the right kind of roughness in the tooth, or make a perfect gin saw tooth The device consists of a circular file, A, of tlie form shown, attached to an arbor revolved by means of a crank The arbor, file, and crank, are supported in a castiron frame, the portion carrying the arbor being pivoted to the other portion at F An upright arc, Gr, passes through the top part of the frame, and is held at the proper angle by a set screw, II At B and C are slits sawed in the frame, of the right size to admit tlie saw when the instrument is in use, and which prevents lateral motion in the frame The file has upon the back a spiral adjustable tongue,J,shown in the detail at the right of the engraving The file also is cut away at I, to admit a tootli of the saw at each turn of the file The adjustable tongue, J, thus acts like a screw to force the saw along one tooth at each turn of the file The shape of the file is such that the teeth are constantly kept at the same length, a vital point in the proper working of a cotton gin A semicircular block of cast iron, D, is pivoted to the frame at E, which serves as a gage in securing the proper position of the frame In operation the frame is grasped in the middle of the bow by the left hand, and the crank is turned by the right hand The inventor claims that this is the only way to give a correct finish to gin saw teeth, and to restore worn or shortened teeth to their original length and perfection of surface Patented, Sept 14, 1868, by A Ii Burdine, Taylor's Depot, Miss Further information may be obtained by addressing Israel F Brown, New London, Conn, or the patentee, as above Improvement in Keyhole Guards This is one of those small inventions alluded to in our editorial of Aug 7th, that can scarcely fail to prove remunerative unless through bad business management on the part of the inventor Nothing could be more simple and subseive fully tlie purpose for which it is intended It is a wellknown and common practice for burglars to thrust in a pair of strong and slender nippers from the outside, and, grasping the end of the key which protrudes through the lock, to turn it and throw back the bolt With such ease and certainty can they do this on ordinary door locks, that it is even less trouble than to pick the lock were the key left out With ordinary locks neither leaving the key in the lock noi taking it out, affords any security from pick locks The inventor of this improvement justly believes that the place for a key, when people are locked up in a house, is in the lock, so that ready escape can be made in case of fire, and he has set himself to work to enable this to be done and at the same time to effectually foil the burglars The engraving well illustrates how this is done Fig 1 represents the lock with the key inserted on the inside, and Fig 2 an opposite view of the same The lock is provided with a front and also a back guard, or escutcheon, attached to a common pivot, and placed at angles with each other, so that when the inside escutcheon is pushed aside, the outside one covers the keyhole on that side, and vice versa The inside one, A, is pushed aside by hand in the usual manner, the outside one, C, Fig 2, then covering the hole so that a person outside the door cannot thrust in a key further than the guard, and cannot by any means move the bolt of the lock Neither can he by any means push aside the guard when the key is left in the lock on the inside, as both the inside guard, A, Figs 1 and 2, and the outside one, C, are countersunk ; to admit the end of the key, which thus prevents all lateral mo; tion The guard, A, has a curved edge at B, which fits into a groove turned in the shank of the key, so that the latter cannot be withdrawn from the inside without pushing aside the guard, nor be jarred out by opening and shutting the door A coiled spring is fixed upon the common pivot of the two guards, or escutcheons, which, when the key is taken out from the inside of the door, forces the guard, A, to cover the j keyhole on the inside, at the same time throwing aside the guard, C, into the position shown by the dotted outline in Fig 2, so that whenever the key is withdrawn from the inside it can be readily inserted from the outside The guard, A, is protected from being broken away through carelessness of servants, or other cause, by means of a staple riveted to the inside plate of the lock, as shown in Fig 1, under which it can move laterally as far as required The features of the invention are, then, the attaching the opposite guards at angles with each other to a common pivot actuated by a spring, so that when the keyhole is uncovered on one side it is covered on the other ; the device by which the key is prevented, from falling, or being pulled out of the lock; the countersinking the under side of the guards to admit the end of the key; and the supporting the inner guard by the staple, as described Patented Aug 11, 1868, by Alfred Huffnaglc, No 8, South Fifth street, Philadelphia, who maybe addressed for a portion or the entire right for the United States Iron Manufacture in tlie West We are glad to learn that tlie manufacture of iron is making progress in the West Tlie North Chicago, the Wyandotte, and the Milwaukee rolling companies are three distinct enterprises, which, the Chicago Tribune remarks, owe their existence and prosperity to the farsightedness and energy of Captain E B Ward, who, when he first moved in the matter, was everywhere assured that he could not successfully contend against Eastern manufacturers, and found himself unable to get one dollar of the stock taken in Chicago or among the railroad companies of the West who were to be directly bene fited by it Recently, moneyed men of Boston, New Bedford, and other Eastern cities, such as Forbes, Brooks, Bartlett, and Thaycr, have united in largely increasing the capital stock of these three companies, and a purchase has been made by them jointly of the Swedes iron mines, lying forty miles northwest of Milwaukee, where ore of peculiar richness and good qualities can be mined at a low cost One million and a half of dollars have been subscribed, of which eight hundred thousand are in the name of tlie North Chicago Mills, a company which already represented one million of dollars As enlarged, this important corporation will employ one thousand six hundred men, including with their families a population of eight thousand persons The three companies together will give work to three thousand operatives, supporting an aggregate population of fifteen thousand souls The whole annual product of the three companies will be three and a half millions of dollars The Chicago Tribune says of these mills, before their recent enlargement, that of one hundred and fifty thousand tuns of iron rails which they had turned out since they began operations, not a single rail has proved defective and no accident has ever resulted from their use Hereafter it is confidently expected that they will be equal to the manufacture annually of thirtyfive thousand tuns of new rails, and fifty five thousand tuns of rerolled, iron The Swedes iron mines are geologically peculiar in the admixture of a large amount of fossil remains in the ore, superseding the employment of lime in fluxing Few other deposits of this character are known to exist, and those only in Sweden The ore is also mixed with manganese, which is said to impart to the iron manufactured from it a steellike toughness of fiber admirably fitting it for rail heads, or the upper half of the longitudinal rail The companies propose to use the Swedes iron chiefly for the rail heads, in the proportion of three fourths Swedes to one fourth Lake Superior iron, which they say will give a surface equal in hardness to the Bessemer steel; making the lower half or base of the rail of three fourths Lake Superior to one fourth Swedes, thus securing a rail that may be bent double without breaking The advantage these iron rails will have over those of the Bessemer steel is, it is asserted, that when so worn as to be unfit for further use, they can be rerolled, whereas the Bessemer steel rails when disintegrated or broken are worthless The Evening Post, in publishing the above facts, calls Capt Ward " a fanatical protectionist" That is very possible, but of one thing we feel tolerably certain, viz, tliat Capt Ward would not have risked his own capital in these great enterprises had lie felt assured of the prevalence of the free trade notions of the Evening Post The industry of tlie West is likely to be considerably benefited in consequence of the " fanatical" A^iews of Capt Ward Magnetism The French Academy of Sciences has received a paper from M J Jamin, in which he shows that magnetism may be condensed, just like electricity Having, for some special purposes, had a large horseshoe magnet made, consisting of ten laminae of perfectly homogeneous steel, each weighing 10 kilogrammes, he suspended it to a hook attached to a strong beam, and, having wound copper wire around each of the legs, which were turned downwards, he put the latter into communication with a battery of 50 of Bunsen's elements, by which means the horseshoe might be magnetized either positively or negatively, at pleasure The variations were indicated by a small horizontal needle, situated in the plane of the poles There was, further, a series of iron plates,which could be separately applied to each of the laminae Before attaching any of the latter, the electric current was driven through the apparatus for a few minutes, and then interrupted, whereby the magnet acquired its first degree of saturation, marked by a certain deviation of the needle One of the iron plates (usually called " contacts ") was then put on, and it supported a weight of 140 kilogrammes A second trial was now made ; and the current having passed through again for a few seconds, it was found that the horseshoe would support 300 kilogrammes, instead of 140 The number of contacts being now increased to five, which together, in the natural state, supported 120 kilogrammes, it was found, after the passage of the current, that they could support the enormous weight of 680 kilogrammes, which they did for the space of a full week No sooner, however, were the contacts taken off than the horseshoe returned to its usual permanent strength of 140 kilogrammes This leads to show that magnetism may be condensed like electricity for a short period THE commission of engineers on the East River Bridge, consisting of Allen, Latrobe, Serrell, McAlpine, Kirkwood, Adams, and Steele, met in this city on the 4th inst, and after a thorough examination of all the details of Mr Roebling's plans, have approved them The chairman recommended, as the successor of Mr# Roebliug,his son, WARoebling He was accordingly elected