Volume 26 (1873) (431 pages)

January 4, 1873.] MINING AND SCIENTIFIC PRESS. 2] Cy) Ni ECHANICAL P roaREss Bessemer’s Steady Ship Saloon. The saloon devised for nse on Mr. Bessamer’a Anti-Seasick Channel Boat is said to he a marvel of mechanical ingenuity. A saloon floor of workiag size has heen constrncted and put iu operatiou near his residence, iu connection with a mechanical apparatus which is said to impart to it all the motions to whichit would bo snbjected within a ship’s hull, and in a heavy, chopping sea. The visitor, when he steps upon tho improvised deck, if at all liable to such sensations, soou becomee subject to all the phenomena of sea-sickness; while if he euters the ‘’saloon"’ he feels no disagreeshlo motion, or noue at least which will produce scasickuess. The Loudon Times describes the device suhstantially as follows:— Looking into the functions to ho performed by this governing mechanism iu tho proposed ship, we first have to suppose a large aud strong floor, which, at its ends and at two intermediate points of its length, rests on steel axes, of about the diameter of the driviag axle of alocomotive. The sapporting frames are securely fixed to the douhle hottom of tho vessel. This floor, then, is capthle of a motion like the heam of a pnmping engine. By raising the sides of the floor and covering it in with a roof it forms a saloon, and if as mnech dead weight he placed below the beams of the floor as will counterbalance the npper part of the structnre the saloon will be in a stnte of equilibrium and capable of motion on its sxis. In this condition it is lisble to be put in motion by the movement of passengers or by the force of the wind blowing agninst the upper part. Hydranlie power heing here judiciously appled prevents ary such erratic motion, and affords a means of retaining the ssloon in a vertical position at the will of the man operatinert apparatus, notwithstanding that the veseel in which it rests is moving beneath it. In order to effect this end a toothed sector of large diameter is secured to the main central axis of the structure, and beneath it is a strong bed plate firmly attached to the floor of the ship. On this bed plate are two hydraulic cylinders, to which a donble-ended ram is fitted, the central part of the ram being provided with teeth, which gesrinto the sector. Therefore, when the ship is in a state of rest, the slidiug in and out of the rams will canse the saloon to move on its own axis with a gentle but powerful motion, These movemeuts, however, are controlled by a pair of delicately halancod equilibrium valves, Henee, it willbe seen that when the ship is rolling at sea the power of acting on the saloon enables the steersman to retain the saloon constantly in a perfectly vertical position, while the floor of the ship rises and falls heneath it. The essential point of this very ingenious arrangement is that the hydraulic apparatus has not to put the saloon in motion, but simply to prevent it acquiring any motion. Moreover, the vis inertia of a structare like the saloon, which will weigh some 70 or 80 tons, will greatly assist in resisting the iniatial tendency to motion. In other respects Mr. Bessemer’s saloon offers undonbted advantages. Resting, as it will, on four axial snpports bedded on an _elastic packing of large area, it will be completely insulated, and will not be susceptible to the violent tremulous motion imparted by the engines and paddles. Again, the heavy thud of the sea against the sides of the ship, so objectionable in cahins bnilt against the framing of the vessel, will be wholly unfelt, as there will be a spsce of five feet hetween the saloon and the sides of the ship, from which, in fact, it will be totally disconnected. Before long the merits of the invention will be put to the test in a couple of vessels huilt from Mr. Reed’s designs, and it is the opinion of all who are competent to form one, thatin them Mr. Bessemer will tind his expectations fully realized. The invention is an ingenious applieation of well known mechanical principles, wherein hydrostatic force in transmitting power and in regulating the irregular action of the machine forms an interesting and most essential featnre. Mr, Bessemer hae already manifested much ingenuity in his varioue applications of hydrostatic force; but if we except this new application, perhaps, the most remarkable of all the various purposee for which he hae introduced hydranlie apparatus is its application to the movement of the large converting vessels used in his eteel/manufacture. These vessele weighing from 10 to 20 tone are nnder the absolute control of a boy placed 60 feet ahove them, when by means of a simple handle he canalter their position to the fractional part of an inch, or move them entirely aronnd a circle, although their fluid contents—to eay nothingofthe weight of the converters themselves—of five tons, are conetantly changing their balance. With this successful appliance'in mind, it is eaey ta perceive how readily Mr. Beesemer might control the unwieldly and irregular movements of even euch a mammoth thing as a 70foot steamboat ealoon, loaded with a full complement of passengers. Resistance of Building-Stone to Heat. The great fires at Chicago and New York have attracted much attention to the relative values of different kinds of bailding-stone in resisting the heat generated in great conflagrations. Mr. Wight, after the Chicago fire, carefully collected snch facts and evidence as seemed most pertineut to this qnestion, and embodied the same iu an address before the Ameriean Institnte of Architects, at Boston. It is stated that in the Chicago fire none of the limestones stood the test of heat; hut some were worse than others. Tho [Illinois limestone ‘‘was, invery many instances, entirely calcined.” ‘‘With regard to this stone,” says Mr. Wight, “it was a common thing for it to explode whcu the heat came suddeuly upon it and was very inteuse. It seewed to calcine with great rapidity, and [I suppose the effect was very much liko that seen iu the manufacture of popcorn. The limestones used for building consist essentially of carbonates of lime, or of carhonate of lime and niagnesia—the latter being known as dolomite. Wheu limestone is exposed to a red heat, the carbonie acid is driven off and the stone crumbles iuto "burnt lime.’’ Limestone free from magnesia, however, will stand a much higher heat than the dolomite--the latter crumbling at 600° Fah., a tomperature which leaves the former iutuct. Mr. Wight spenks of the so-called ‘petroleum stone,” which was reported to be entirely consumed, hut which, in fact, stood the heat very well. There was oue churchin Chicago built of this stone, in which the amount of oil was so great that the heat of the sun would draw it out soon sfter the stoue was set np in a wall, and it would run down in black streaks. ‘‘The effect of the heat on the inside of the walls threw out npon the exterior all the oil it contained, which formed a thick, hard coating, ahout a quarter of aninch in thickness; and though the interior of the church was exposed to great heat, and every particle of wood iu it was hurned up so that there wae not ascrap left in it, the interior sides of its walls were not greatly injured. In some places the stone had flaked off, and yet this stone etood the test better than any other natural stone used in the city.” The great resistance of this stone to the heat was not, of course, due to the oil which it coutained; but to the fact that, thongh eslled a limestone, it really contained from 20 to 30 per cent. of eilica and alumiua, which eubstances, the latter in particular, are distinguished for their capacity to resist heat, Their presence, intimately mixed with the lime, protects it from disintegrating, The oil on the interior of the wall was protected from burning from the fact that the interior of the building was inaccesslhle to the free entrance of air. Saudstones stood the heat best at Chicago, and proved the excellence of that material for fire-proof structures. The only bnilding in the burnt district of the south side at Chicago, which stood intact, was of Cleveland sandstone. ''In that building there was not a flaw, nothing cracked or broken.’’ Sandstone is made up of from 80 to 90 per cent. of silica, the balance consisting of alumina, lime, magnesia, iron, etc. The oxide of iron is ususlly the cementing material. Granite, quartz, slate, and most other rocks of that class used for building purposes, are liahle to crack, oftentimes in an explosive manuer. This is due to the fact that they contain a cousiderable quantity of water, mechanically held within their interstices. Quarrymen and miners will often, on examining the walls of such rocks immediately after blasting, notice that they are more or less moist—the moisture being sometimes so great as to collect in drops and even run down the face of the recent fracture. This moisture is retsined in building blocks, and when great heat is applied, being converted into steam, causes explosions, as above. Sandstone is quite free from moisture; hence, chiefly, its power to resist the action of heat. Artificial stones, compesed of silicate of lime and alumina, with water chemically combined —not mechanically enclosed—are of the nature of sandstones, and are well-calculated to resist heat. It ie said that large nnmbersof the Frear stone blocks which passed through the Chicago fire, and which do not contain any free water, are beiug used the second time in the construction of other buildiugs. Bricks, if of good quality, resist the action of fire very well. If they contain material which vitrifiee readily they lose their etrength and succumb. ‘True, they ahsorb water easily, but they part with it eo readily that no danger eneues from that cause. When good bricke are built into a wall of proper thickness they form about as indestructible a material as can he used for resisting a great heat. We have not as yet eeen any report npon the particular and comparative effect of heat npon the stone and brick material subjected to the heat of the recent Boston fire. Careful observatione have no doubt heen made, the results of which will donbtless ere long find their way into print. Quite too Httle attention is paid by builders and architects to the heat resisting capacity of the stone they nse. More attention is paid to the crushing strain which it will bear iad the facility with which it may be worked. Mineralogy and chemistry are quite as essential to the architect in determining the selection of his building materials as ie the hydraulic press. GCENTIFIC Progress. Experiments in Nature’s Laboratory. The experimental method, now souniversally accepted as the sole means of arriviug at scientific facts, is mostly carried out in laboratories provided with more or less expensive apparatus, which, however large aud commodioue, rivals in a pitifully small degree tho grand, subtle, and delicate appliances of uature. No artificial arraugements cau emulate tho enormous pressuree to which in nature various 1aterials are subjected. No furnace constructed by man, though seven times heated, can appreach iu iutensity of action the heat of volcanic ori gin; aud this last is, so to speak, cold when compared to the high temperatures of the solar atmosphere, What comparison can he made between all tho varied aud skillfully coutrived apparatus of moderu chemistry aud that which exists in the respiratory, digestive, aud ciiculatory organs of animals, or even plants? Not all the instruments aud processes yet devised by man for investigatton of orgauie chemistry are equal to the construction of a blood-corpuscle, a cell, or an animal tissue. We know that these things are produced in obedience to law, as surely as that winds blow, iron rusts, and rivers flow in accordauce with fixed and invariahle principles. Could weestahlish the proper conditions, a blood-corpuscle would result. The feeble experiments of the philosopher are merely attempts to establish iu each crse a determinate set of conditions. This done, he awaits results. It is only through the agency of natural law that he establishes conditions, he himself acting in as blind obedience to law as does the clod from which he culls a specimen, He even thinks in ohedience to law, from which he can no more escspe than matter can escape from the mysterious influence celled gravity. People ofteu speak about violating a law of nature, and of the punishment which follows such violation, Thefact is, however, that there is no such thing as breaking through natural law. If we eat that which nourishes us, we are nourished accordiugto law. If we take arsenic, it acts to poison us in obedience to other provisions of the same inexorahle code. Tobacco entails nervous and other disorders upon man, when used ae a stimulant, uuder the same law that it kills ticks on lambs, Nature is perfectly indifferent whether a flame hurns eticks or our fingers. It is the eterual fiat that gases heated to incandesceuce shall produce certain effects on certain other substances, and neither sticks nor fiugers can avade the everlasting unchangeable decree. Underlyiag the ever-changing complexity of phenomena is the never-changing,inflexihle, sternly coherent law, so much superior to the puny will aud strenth of man that one wonders at even the careless application to it of the term ‘‘violation.’’ tis questionable whether, in the seareh for artificial appliances through which to control conditions, we have not in some measure come to underrate the vslue of close observation of results of conditions already established in nature. It is quite recent that we have learned to sppreciate the possible effects of windsin abrading rocks exposed to theiraction. The artificial application of the sand blast to the cutting of the hardest suhstances within the last two or three yearsisonly a repetition of a process which has been going on under the eyes of mankind for ages. Who has ever thonght of consulting any of the processes going on inthe natural world for confirmation or negation of the elementary chsracter of those substances now called chemies] elements ? Who has said, ‘Inasmuch as the chemical processes of digestion and assimilatiou are infinitely more refined than any I ean conduct, let me see whetheriu the animal or vegetable economy phosphorus or sulphur (which are, to say at least, open to the suspicion of compound character) is not sometimes produced from food which contains neither ?’’ Should such a fact ever he discovered, it would as effectually settle the composite character of phosphorus or sniphur as could the most successful laboratory analysis. All honor to the splendid corps of investigators—now, thank God! in no want of reeruits—who are forcing their way into the interpenetralia of nature in echoole, in laboratories, in shops, and in garrets! All honor to the genius that hasgiven us the balance, the thermometer, and the barometer; that has widened our field of vision by the microscope, the telescope, and the spectroscope! All houor to him, though the humblest, who has added one implement to our common etock! Yet, with due reverence to genius we helieve there is something to be seen with unaided eyes, and outside the lahoratories and oheervatories of our universities.—Am. Artisan. Nicztz asa Gas Occiruper.—Prof. Raoult of Grenoble, has proved that nickle employed for twelve hours asa negative electrode in a voltameter, condences at least 150 times ite volume of hydrogen and abandons entirely this gas, when.it ie taken fromthe voltameter and plunged iu water. M. Raoult has made éeveral experiments on the production of calorie and has encceeded in demonstrating that the inteneity of the heat developed by an electric current is independent of the system of battery by which the current is engendered. Heating Water Above the Boiling Point in Open Vessels. M. Donny, a French experimentalist, found that water deprived of air could be raised to a temperature of 2809 Fuh., without boiling, and that evaporation then took place explosively, tho water discharging a snfficient amount of steam ata single burst to reduce its temperature to that due the pressuro to which it was exposed. M. Deluc observed the fact even earlier than Donny, and physicists have attacked the subject siuce. M. Dnfour, by taking the most delicate method and ohserving the greatest care to avoid contact of rough particles and metallic surfaces with the water, sneceeded in raising the temperaturo of very minute globules 3479 Fah., which is that due to steam under a pressure of 115 pounds to the square inch. It is found necessary, however, in such experiments, to operate with very clean water in very small quantities, and to be exceedingly careful to avoid the slightest motion of the liqnid, and also to keep it from contact with metallic surfaces or mineral substances. M.Donny’s experiments were made with glass vessels, hut M. Dufour was compelled to suspend his drops of water ina mixture of oil of cloves and linseed oil, to secure the success of his experiment. Such conditions evidently never occur where water is vaporized in steam boilers, and we may probably feel confident that such superheating is not likely to produce steam hoiler explosions. The msss of water in a steamhoiler is too large, and is invariably in contact with a metallic surface. It is probably always iu motion, at least, toa slight extent, as the irregular distrihution of heat in all ordinary boilers, must produce generally some slight circulation at all times; and finally it rarely happens that feed water is absolutely free from imparities. While, therefore, we cannot say positively that explosions have never occurred, from this cause, we are fully justified, probably, in eupposing it to be the fact.—Scientific American. Origin of Storms. Mr. John Hepburn, of Gloucester, N. J., writes to the Scientific American, that a careful observation of twelve years past has satisfied him that ‘‘storms are nursed into being by the action of electricity from the sun, and that the rays of the eun drives the storms before them.” He says: “'I have made a specialty of watching the firet traces of gust march, and I have invariably found that morning gusts come from the east; mid-day gusts from the south and eveuing gusts from the west, and I feel quite sure that if scientists will devote a little timo to the first appearance of any cominggust, they will find and admit that there is truth in the theory I have advanced. I am of the opinion that solar electricity produces earth storms, and that most earthqaakes are produced by the same agency.” He has noticed that black, stormy clouds advance from the sun, psss on heyond, or mske a stand overhesd, and in the latter case mix more and run into each other in very great commotion; then begin to break and act with fearful violence npon the earth, sendingtorrents of rain or hail in au opposite direction to that of its original march. He has also noticed gusts come up, along through the clouds, pass overhead, and for some distance beyond, theu return against or at a greater or less angle to the sun’s rays. What he appears to claim as his theory is, that the gusts are first set in motion in a line with and before the sun’e rays; but that when once so put in motion the cloud thus formed may be driven more or less out of its direct motion hy side currents, before it commences to discharge itsaqueous contents, or otherwise expeud its accumulated fury. “‘Gumuate or Inon”’ Paper.—Many years ago Fremy discovered, very unexpectedly at the time to the chemical world, that gum, instead of beiug, as previously held, an isomerio form of starch or cellulose, was the lime aslt of a peculiar acid, gummic acid. The British Journat of Photography states that, very curiously, gummie acid combines with ferric oxyd, forming what may be called an iron gum. To coat paper, which is then sensitive to light, ‘‘a soIntion of perchloride of iron ietaken, ammonia cautiously added with agitation nntil a permanent precipitate makes its appearance. The liquid then filtered, paper eaturated with the solution, and allowed to dry in the dark. The coated eheets then floated on eome thick mucilage of gum-arabic. The surface of the paper is thns covered with an even layer of the “gummate of iron.'’ When the paper oarrying the iron is first coated with the mucilage, the color doee not at once change, but presently a etrong, yellowieh-brown tint ie produced, and the gum ’ eets,’ and then the layer dries up, leaving the paper very flexible for a long time, and highly glazed.” Tarra 1s No Opsecr Unworray or Our NoTIce.—‘’While I am reading” saye a careful etudent on uatural history, ‘‘a fly settles on my hand;Idon’t killit; I watch it, with a glass perhaps, and eee it clean its wings and ite head, aud make friends with it till I feel I can speak to that fly; and so it is with everything living. If we will humble ourselves and condescend to look at the apparently lowest creatures, we shall find instruction in the meanest of them.”

January 4, 1873.] MINING AND SCIENTIFIC PRESS. 2] Cy) Ni ECHANICAL P roaREss Bessemer’s Steady Ship Saloon. The saloon devised for nse on Mr. Bessamer’a Anti-Seasick Channel Boat is said to he a marvel of mechanical ingenuity. A saloon floor of workiag size has heen constrncted and put iu operatiou near his residence, iu connection with a mechanical apparatus which is said to impart to it all the motions to whichit would bo snbjected within a ship’s hull, and in a heavy, chopping sea. The visitor, when he steps upon tho improvised deck, if at all liable to such sensations, soou becomee subject to all the phenomena of sea-sickness; while if he euters the ‘’saloon"’ he feels no disagreeshlo motion, or noue at least which will produce scasickuess. The Loudon Times describes the device suhstantially as follows:— Looking into the functions to ho performed by this governing mechanism iu tho proposed ship, we first have to suppose a large aud strong floor, which, at its ends and at two intermediate points of its length, rests on steel axes, of about the diameter of the driviag axle of alocomotive. The sapporting frames are securely fixed to the douhle hottom of tho vessel. This floor, then, is capthle of a motion like the heam of a pnmping engine. By raising the sides of the floor and covering it in with a roof it forms a saloon, and if as mnech dead weight he placed below the beams of the floor as will counterbalance the npper part of the structnre the saloon will be in a stnte of equilibrium and capable of motion on its sxis. In this condition it is lisble to be put in motion by the movement of passengers or by the force of the wind blowing agninst the upper part. Hydranlie power heing here judiciously appled prevents ary such erratic motion, and affords a means of retaining the ssloon in a vertical position at the will of the man operatinert apparatus, notwithstanding that the veseel in which it rests is moving beneath it. In order to effect this end a toothed sector of large diameter is secured to the main central axis of the structure, and beneath it is a strong bed plate firmly attached to the floor of the ship. On this bed plate are two hydraulic cylinders, to which a donble-ended ram is fitted, the central part of the ram being provided with teeth, which gesrinto the sector. Therefore, when the ship is in a state of rest, the slidiug in and out of the rams will canse the saloon to move on its own axis with a gentle but powerful motion, These movemeuts, however, are controlled by a pair of delicately halancod equilibrium valves, Henee, it willbe seen that when the ship is rolling at sea the power of acting on the saloon enables the steersman to retain the saloon constantly in a perfectly vertical position, while the floor of the ship rises and falls heneath it. The essential point of this very ingenious arrangement is that the hydraulic apparatus has not to put the saloon in motion, but simply to prevent it acquiring any motion. Moreover, the vis inertia of a structare like the saloon, which will weigh some 70 or 80 tons, will greatly assist in resisting the iniatial tendency to motion. In other respects Mr. Bessemer’s saloon offers undonbted advantages. Resting, as it will, on four axial snpports bedded on an _elastic packing of large area, it will be completely insulated, and will not be susceptible to the violent tremulous motion imparted by the engines and paddles. Again, the heavy thud of the sea against the sides of the ship, so objectionable in cahins bnilt against the framing of the vessel, will be wholly unfelt, as there will be a spsce of five feet hetween the saloon and the sides of the ship, from which, in fact, it will be totally disconnected. Before long the merits of the invention will be put to the test in a couple of vessels huilt from Mr. Reed’s designs, and it is the opinion of all who are competent to form one, thatin them Mr. Bessemer will tind his expectations fully realized. The invention is an ingenious applieation of well known mechanical principles, wherein hydrostatic force in transmitting power and in regulating the irregular action of the machine forms an interesting and most essential featnre. Mr, Bessemer hae already manifested much ingenuity in his varioue applications of hydrostatic force; but if we except this new application, perhaps, the most remarkable of all the various purposee for which he hae introduced hydranlie apparatus is its application to the movement of the large converting vessels used in his eteel/manufacture. These vessele weighing from 10 to 20 tone are nnder the absolute control of a boy placed 60 feet ahove them, when by means of a simple handle he canalter their position to the fractional part of an inch, or move them entirely aronnd a circle, although their fluid contents—to eay nothingofthe weight of the converters themselves—of five tons, are conetantly changing their balance. With this successful appliance'in mind, it is eaey ta perceive how readily Mr. Beesemer might control the unwieldly and irregular movements of even euch a mammoth thing as a 70foot steamboat ealoon, loaded with a full complement of passengers. Resistance of Building-Stone to Heat. The great fires at Chicago and New York have attracted much attention to the relative values of different kinds of bailding-stone in resisting the heat generated in great conflagrations. Mr. Wight, after the Chicago fire, carefully collected snch facts and evidence as seemed most pertineut to this qnestion, and embodied the same iu an address before the Ameriean Institnte of Architects, at Boston. It is stated that in the Chicago fire none of the limestones stood the test of heat; hut some were worse than others. Tho [Illinois limestone ‘‘was, invery many instances, entirely calcined.” ‘‘With regard to this stone,” says Mr. Wight, “it was a common thing for it to explode whcu the heat came suddeuly upon it and was very inteuse. It seewed to calcine with great rapidity, and [I suppose the effect was very much liko that seen iu the manufacture of popcorn. The limestones used for building consist essentially of carbonates of lime, or of carhonate of lime and niagnesia—the latter being known as dolomite. Wheu limestone is exposed to a red heat, the carbonie acid is driven off and the stone crumbles iuto "burnt lime.’’ Limestone free from magnesia, however, will stand a much higher heat than the dolomite--the latter crumbling at 600° Fah., a tomperature which leaves the former iutuct. Mr. Wight spenks of the so-called ‘petroleum stone,” which was reported to be entirely consumed, hut which, in fact, stood the heat very well. There was oue churchin Chicago built of this stone, in which the amount of oil was so great that the heat of the sun would draw it out soon sfter the stoue was set np in a wall, and it would run down in black streaks. ‘‘The effect of the heat on the inside of the walls threw out npon the exterior all the oil it contained, which formed a thick, hard coating, ahout a quarter of aninch in thickness; and though the interior of the church was exposed to great heat, and every particle of wood iu it was hurned up so that there wae not ascrap left in it, the interior sides of its walls were not greatly injured. In some places the stone had flaked off, and yet this stone etood the test better than any other natural stone used in the city.” The great resistance of this stone to the heat was not, of course, due to the oil which it coutained; but to the fact that, thongh eslled a limestone, it really contained from 20 to 30 per cent. of eilica and alumiua, which eubstances, the latter in particular, are distinguished for their capacity to resist heat, Their presence, intimately mixed with the lime, protects it from disintegrating, The oil on the interior of the wall was protected from burning from the fact that the interior of the building was inaccesslhle to the free entrance of air. Saudstones stood the heat best at Chicago, and proved the excellence of that material for fire-proof structures. The only bnilding in the burnt district of the south side at Chicago, which stood intact, was of Cleveland sandstone. ''In that building there was not a flaw, nothing cracked or broken.’’ Sandstone is made up of from 80 to 90 per cent. of silica, the balance consisting of alumina, lime, magnesia, iron, etc. The oxide of iron is ususlly the cementing material. Granite, quartz, slate, and most other rocks of that class used for building purposes, are liahle to crack, oftentimes in an explosive manuer. This is due to the fact that they contain a cousiderable quantity of water, mechanically held within their interstices. Quarrymen and miners will often, on examining the walls of such rocks immediately after blasting, notice that they are more or less moist—the moisture being sometimes so great as to collect in drops and even run down the face of the recent fracture. This moisture is retsined in building blocks, and when great heat is applied, being converted into steam, causes explosions, as above. Sandstone is quite free from moisture; hence, chiefly, its power to resist the action of heat. Artificial stones, compesed of silicate of lime and alumina, with water chemically combined —not mechanically enclosed—are of the nature of sandstones, and are well-calculated to resist heat. It ie said that large nnmbersof the Frear stone blocks which passed through the Chicago fire, and which do not contain any free water, are beiug used the second time in the construction of other buildiugs. Bricks, if of good quality, resist the action of fire very well. If they contain material which vitrifiee readily they lose their etrength and succumb. ‘True, they ahsorb water easily, but they part with it eo readily that no danger eneues from that cause. When good bricke are built into a wall of proper thickness they form about as indestructible a material as can he used for resisting a great heat. We have not as yet eeen any report npon the particular and comparative effect of heat npon the stone and brick material subjected to the heat of the recent Boston fire. Careful observatione have no doubt heen made, the results of which will donbtless ere long find their way into print. Quite too Httle attention is paid by builders and architects to the heat resisting capacity of the stone they nse. More attention is paid to the crushing strain which it will bear iad the facility with which it may be worked. Mineralogy and chemistry are quite as essential to the architect in determining the selection of his building materials as ie the hydraulic press. GCENTIFIC Progress.

Experiments in Nature’s Laboratory. The experimental method, now souniversally accepted as the sole means of arriviug at scientific facts, is mostly carried out in laboratories provided with more or less expensive apparatus, which, however large aud commodioue, rivals in a pitifully small degree tho grand, subtle, and delicate appliances of uature. No artificial arraugements cau emulate tho enormous pressuree to which in nature various 1aterials are subjected. No furnace constructed by man, though seven times heated, can appreach iu iutensity of action the heat of volcanic ori gin; aud this last is, so to speak, cold when compared to the high temperatures of the solar atmosphere, What comparison can he made between all tho varied aud skillfully coutrived apparatus of moderu chemistry aud that which exists in the respiratory, digestive, aud ciiculatory organs of animals, or even plants? Not all the instruments aud processes yet devised by man for investigatton of orgauie chemistry are equal to the construction of a blood-corpuscle, a cell, or an animal tissue. We know that these things are produced in obedience to law, as surely as that winds blow, iron rusts, and rivers flow in accordauce with fixed and invariahle principles. Could weestahlish the proper conditions, a blood-corpuscle would result. The feeble experiments of the philosopher are merely attempts to establish iu each crse a determinate set of conditions. This done, he awaits results. It is only through the agency of natural law that he establishes conditions, he himself acting in as blind obedience to law as does the clod from which he culls a specimen, He even thinks in ohedience to law, from which he can no more escspe than matter can escape from the mysterious influence celled gravity. People ofteu speak about violating a law of nature, and of the punishment which follows such violation, Thefact is, however, that there is no such thing as breaking through natural law. If we eat that which nourishes us, we are nourished accordiugto law. If we take arsenic, it acts to poison us in obedience to other provisions of the same inexorahle code. Tobacco entails nervous and other disorders upon man, when used ae a stimulant, uuder the same law that it kills ticks on lambs, Nature is perfectly indifferent whether a flame hurns eticks or our fingers. It is the eterual fiat that gases heated to incandesceuce shall produce certain effects on certain other substances, and neither sticks nor fiugers can avade the everlasting unchangeable decree. Underlyiag the ever-changing complexity of phenomena is the never-changing,inflexihle, sternly coherent law, so much superior to the puny will aud strenth of man that one wonders at even the careless application to it of the term ‘‘violation.’’ tis questionable whether, in the seareh for artificial appliances through which to control conditions, we have not in some measure come to underrate the vslue of close observation of results of conditions already established in nature. It is quite recent that we have learned to sppreciate the possible effects of windsin abrading rocks exposed to theiraction. The artificial application of the sand blast to the cutting of the hardest suhstances within the last two or three yearsisonly a repetition of a process which has been going on under the eyes of mankind for ages. Who has ever thonght of consulting any of the processes going on inthe natural world for confirmation or negation of the elementary chsracter of those substances now called chemies] elements ? Who has said, ‘Inasmuch as the chemical processes of digestion and assimilatiou are infinitely more refined than any I ean conduct, let me see whetheriu the animal or vegetable economy phosphorus or sulphur (which are, to say at least, open to the suspicion of compound character) is not sometimes produced from food which contains neither ?’’ Should such a fact ever he discovered, it would as effectually settle the composite character of phosphorus or sniphur as could the most successful laboratory analysis. All honor to the splendid corps of investigators—now, thank God! in no want of reeruits—who are forcing their way into the interpenetralia of nature in echoole, in laboratories, in shops, and in garrets! All honor to the genius that hasgiven us the balance, the thermometer, and the barometer; that has widened our field of vision by the microscope, the telescope, and the spectroscope! All houor to him, though the humblest, who has added one implement to our common etock! Yet, with due reverence to genius we helieve there is something to be seen with unaided eyes, and outside the lahoratories and oheervatories of our universities.—Am. Artisan. Nicztz asa Gas Occiruper.—Prof. Raoult of Grenoble, has proved that nickle employed for twelve hours asa negative electrode in a voltameter, condences at least 150 times ite volume of hydrogen and abandons entirely this gas, when.it ie taken fromthe voltameter and plunged iu water. M. Raoult has made éeveral experiments on the production of calorie and has encceeded in demonstrating that the inteneity of the heat developed by an electric current is independent of the system of battery by which the current is engendered. Heating Water Above the Boiling Point in Open Vessels. M. Donny, a French experimentalist, found that water deprived of air could be raised to a temperature of 2809 Fuh., without boiling, and that evaporation then took place explosively, tho water discharging a snfficient amount of steam ata single burst to reduce its temperature to that due the pressuro to which it was exposed. M. Deluc observed the fact even earlier than Donny, and physicists have attacked the subject siuce. M. Dnfour, by taking the most delicate method and ohserving the greatest care to avoid contact of rough particles and metallic surfaces with the water, sneceeded in raising the temperaturo of very minute globules 3479 Fah., which is that due to steam under a pressure of 115 pounds to the square inch. It is found necessary, however, in such experiments, to operate with very clean water in very small quantities, and to be exceedingly careful to avoid the slightest motion of the liqnid, and also to keep it from contact with metallic surfaces or mineral substances. M.Donny’s experiments were made with glass vessels, hut M. Dufour was compelled to suspend his drops of water ina mixture of oil of cloves and linseed oil, to secure the success of his experiment. Such conditions evidently never occur where water is vaporized in steam boilers, and we may probably feel confident that such superheating is not likely to produce steam hoiler explosions. The msss of water in a steamhoiler is too large, and is invariably in contact with a metallic surface. It is probably always iu motion, at least, toa slight extent, as the irregular distrihution of heat in all ordinary boilers, must produce generally some slight circulation at all times; and finally it rarely happens that feed water is absolutely free from imparities. While, therefore, we cannot say positively that explosions have never occurred, from this cause, we are fully justified, probably, in eupposing it to be the fact.—Scientific American. Origin of Storms. Mr. John Hepburn, of Gloucester, N. J., writes to the Scientific American, that a careful observation of twelve years past has satisfied him that ‘‘storms are nursed into being by the action of electricity from the sun, and that the rays of the eun drives the storms before them.” He says: “'I have made a specialty of watching the firet traces of gust march, and I have invariably found that morning gusts come from the east; mid-day gusts from the south and eveuing gusts from the west, and I feel quite sure that if scientists will devote a little timo to the first appearance of any cominggust, they will find and admit that there is truth in the theory I have advanced. I am of the opinion that solar electricity produces earth storms, and that most earthqaakes are produced by the same agency.” He has noticed that black, stormy clouds advance from the sun, psss on heyond, or mske a stand overhesd, and in the latter case mix more and run into each other in very great commotion; then begin to break and act with fearful violence npon the earth, sendingtorrents of rain or hail in au opposite direction to that of its original march. He has also noticed gusts come up, along through the clouds, pass overhead, and for some distance beyond, theu return against or at a greater or less angle to the sun’s rays. What he appears to claim as his theory is, that the gusts are first set in motion in a line with and before the sun’e rays; but that when once so put in motion the cloud thus formed may be driven more or less out of its direct motion hy side currents, before it commences to discharge itsaqueous contents, or otherwise expeud its accumulated fury. “‘Gumuate or Inon”’ Paper.—Many years ago Fremy discovered, very unexpectedly at the time to the chemical world, that gum, instead of beiug, as previously held, an isomerio form of starch or cellulose, was the lime aslt of a peculiar acid, gummic acid. The British Journat of Photography states that, very curiously, gummie acid combines with ferric oxyd, forming what may be called an iron gum. To coat paper, which is then sensitive to light, ‘‘a soIntion of perchloride of iron ietaken, ammonia cautiously added with agitation nntil a permanent precipitate makes its appearance. The liquid then filtered, paper eaturated with the solution, and allowed to dry in the dark. The coated eheets then floated on eome thick mucilage of gum-arabic. The surface of the paper is thns covered with an even layer of the “gummate of iron.'’ When the paper oarrying the iron is first coated with the mucilage, the color doee not at once change, but presently a etrong, yellowieh-brown tint ie produced, and the gum ’ eets,’ and then the layer dries up, leaving the paper very flexible for a long time, and highly glazed.” Tarra 1s No Opsecr Unworray or Our NoTIce.—‘’While I am reading” saye a careful etudent on uatural history, ‘‘a fly settles on my hand;Idon’t killit; I watch it, with a glass perhaps, and eee it clean its wings and ite head, aud make friends with it till I feel I can speak to that fly; and so it is with everything living. If we will humble ourselves and condescend to look at the apparently lowest creatures, we shall find instruction in the meanest of them.”