Volume 13 (1866) (424 pages)

The Mining and Scientific Press. 243 — AMechavical, ELEOTRIOITY AS A MOTIVE POWER. A large amount of attention iz being devoted at the present time to efforts for renering electricity ecouomically availahle ae & motive power. Gen. Count de Molin, an Itailjan nohlemop, has recently constructed and patio operation a smiall puddle-whecl hout» which he colls L’ £vectiicitie, He cmploye sixteen of Boosen’s elements tn nbtain his propelling power, which, by careful measurement, has been found to be cquol to noe man power.: The paddle-whecls are two and a half fect to diameter. If wearo not mistuken, we hove an electro magnetic engine in this city that will accomplish more work with lcss expense of material. Mr. C. L. Stewart, of Philudelphiu, recently exhibited, ot the rooms nf the Free Acudemy of New York, in the presence of o number of scientific gentlemen and prominent mechauics, an electro-magnetic motor, of quite o novel construction, which the gentlemen present considered very promising. Mr. Stewart does not yet claim to huve perfected his invention. ‘The relutive cost of the power of this machine as compared with steam, iad not been fully ascertained. ‘he Philadelphia Mining Journal, iu noticing the exhihition of this machine, says that Professor Duremus, of the Free Academy, puve some very interesting explanations and illustrations of the power of electricity, previnus to the explauation of Mr. Stewart's apparatus, and expressed the opinion that, with a suitable opparatus, clectric power may be produced cheaper than eteam power. Aside from the question of cost, there ure other manifest advantoges on the side of electricity. It is cnostantly nnd instantancously ready for use; it produces neither smoke, flame, nor noxious gases; it is perfectly clean; it invclves no’ danger from fire; it is entirely safe; it is noiseless, Should. Mr. Stewart succecd in perfecting his apparatus, it might he advantageously substituted for horse-power in the propulsion of street cars, and, in fact, for nearly all vehicles. Especially on a subterranean road euch a motive power would be invaluable. Mr, Stewart intends soon to make a public triol of his apparatus upon one of the eity railroads. A New Cement.— A late number of the London Engineer announces a new cement of great value, which is introduced under the euplionious title of “The Zopissa Iron Cement,” which, it is claimed, is capable of joining any two solid substances, however dissimilar. Wood, brick, iron, stone, or glass, can be inosepnrably united with great facility. A series of experiments, witnessed by tha Angineer, gave the following results : “ Plates of glass were firmly joined, edge to edge; ordinary bottles stuck upon the wall resisted all attcupts at eepara_tion till the stone yielded. Champagne bottles, cemented bottom to bottom, sustained a weight of two hundred ond filty pounds. ‘I'wo bricks remained joined under a tension of three hundred and twenty-five pounds, till the brick itself fractured, but the cement remained firin. Brickwork cemented with this has the solidity of a granite slab. With paper treated with this preparation in solution, the inventor has made air and water-tight tubes, ammuni. tion cases, coffins, and even constructed a house, one story and a half in hight, perfectly wind and woter-tight, which he now has on exhibition.” Of the constitution of this cement, or the expense of inanufacturing it, the £nginesr makes no intimations.” A New Atitoy.—M.,M. H. Micolon, of Puris, proposes a new alloy for the manufacture of auch metal articles ag bells, hammers, novils, rails, and non-cutting tools. ‘The alloy consists of twenty parts of iron turnings or tinwaste, eighty parts of steel, four parts of manganese, and four parts of borax; but these proportions muy be varied. When it is desired to iucreasa the tenacity of tbe alloy, two or three parts of wollram nore added. When the cupola is ready, the iron and steel are poured in, tben the manganese and borax, and the vessel is filled np with coke. THE HARRISON STEAM BOILER, The HWurrison hoiler, according to the American Artisan, ia now being quite extensively ! introduced into use, and a large establishment hos been erected in Philodelphia for its manufacture. ‘Ihe differeut depurtmenta in this estnblishment aro so arronged, that the manufucture ,ie commenced at one end ond prov ceeded with through its successivo stages until tho boiler is completed ot the other; thn iron received by railroad eotcring on the track through ona door, and passing on throagh the works, withont once returning uotil it leaves the other extremity in the form of boilers ready mode for erection. Six tous of cnstings are snid to he nade up daily into boilers, und sent awuy to fill up orders, which ore constantly increasing. This is indicative of quite an extensive demand. Why is it that this boiler hus not been brought intn use here? On the score of economy and safety, it would be far superior to the ordinury wrought irou boiler. At least one of these boilers has heen set up iu this city ; hut, we understand thot it could not be made to work; for whut reason we are not definitely informed. Our impression, however: is, that the unequal expansion of the joints and fastenings euused the hoiler to leuk so badly that it could not be used. Tbe joints, os used in the instance referred to, were faced with intervening washers of wrought iron, and the whole screwed op tigbtly on longitudinal rods of wrought iron. We perecive, by the account referred to in the Artisan, that the sectious ore now put together, in Philadelphia, by nale and female joints, which are eo carcfully turned and fitted by machinery that they are obsolutely stcam-tight, hy mere contuct of the faces of the metal. By this method the joints ore also interchangeable, so that any oue section may be fitted to another without alteration. If this boiler can he, mnde to work, why might it not be advantageously adopted upon steamships and river stcnmers, and more especially where high-pressure steamers are used ? Two hundred pounds of steam can he carried on one of these boilers with more salety than eighty or one hundred pounds on boilers of ordinary constroction ; and nw serious injury could arise from an explosion, as it could rarely occur thot more than one or twvosections could explode at once, which even then would cause scarcely ony more damage than the bursting of a tube in a tubular boiler. It may, perhaps, he well for some of our enterprising mechanics to look into this matter, and see if something practicable cannot be found in it. We cotice that Messrs. Jas. Harrison and Thomas. L. Saders have patented, in England, a modification of the Harrison hoiler, which consists in casting together a slah, of forty spheres, united hy nicks, instead of mnking such a slab of “units” of four spheres each, held together by bolts. Thus, numerous joints are nvoided. The reason for the ubove change in constrnction is given as follows: « ft ap: pears that when the priming has been violent these joints have leaked.” Our impression is that the “joints” above referred to are the face joints first used, and are not the male and female joints now employed in Philadelphia manufacture, which have only been in general use a little over one year. A Harp Cement.—Tuko iron sponge, triturate finely and mix with sand, moistened with a weak solution of muriatic acid. The iron is oxydized by acidulated water, and’ the silex forms with tbe oxyd a silicate of iron, which possesses great tenacity, and is uot affected by atmospberic changes, or by acid or alkaline liquids of a boiling temperature. This cement will unite, into a solid mass, stones, pebbles, ete., forming conglomerates impervious to moisture, and capable of being moulded into stntues, bas reliefs, ete. This process is simply an imitation of a process of nature, which is sometimes carricd on upon a large scale, in the formation of some of the hardest rocks. Tue Miwerat wealth of England has nearly doubled within the last five years. Scientific Wiseellany. LATE RESEARCHES ON METALS. Althongh science and tha knowledge of metuls has node eteady and nmiost wonderful progress during ths pust fifty years, still it is evident thut, in the study of metals and their alloys, there is much more to be lenrned than has hitheitn been made known. Scoreely o mooth passes wilhout ths onnouucement of the discovery of some new property in some oue of the ordinory metals, or some important fuct counccted with improvemente in their monufacture. It has long becn koown thut light is transinitted through very thin sheets of nearly all the inetals; but it hos ouly quite recently been demonstrated thnt light travels through gold aud silver more rapidly than throogh a yocuum. ‘The porosity of metals ot a high temperature is also a late discovery. It is hut a short time since Veville puhlished some very interesting papers on this sulject. His experiments enabled him’to show that even platinum, when highly heated, is permeahle to yases. ‘I'he existence of this fact is cepecially important to persons engaged in the munufheture of coal gas, where iron retorts are used for distilling the coal. So complete is the permeability of iron at a hieh red heat thot an iron tube filled with bydrogen, ard heated to that degree, will lose all trace of that yas ina few hours. ‘fhis fact is important to chemists ; but more especially important is the discovery thut platinum is also permeahle, for that metal has heretofore been employed in the laboratory under the conviction that its high density and mode of manufacture completely destroyed its porosily. It is only quite recently that it has been found possible to procure ubsolutely pure inctals of any kind, or rather that we have learned that the metals previonsly considered, pure were not so. We have already, in previous numbers, alluded to the extreme diffculty of obtaining pure iron; hut few, even among scientific men, have ever seen iron in such a condition. Pure iron is a white metal, so soft that it can readily he cut with a knife. ‘he changes produced in iron by the presence of even the most minute proportions of impurities, is wonderful—more marked thao in any other metal; hence its adaptability to such a variety of purposes in the arta. Staas, in his experimental researches, has spent months of time to produce even a very minute quantity of absolutcly pure silver, lead, ete. Pure silver, or even iron, are worth much more than their weight in gold. Pure copper is not quite so difficult of attainment, nod the smallest possible impurity can be more readily detected in this than in any other metal. ‘his is done by means of the galvanometer. Perfectly pure copper, when presented to ihe magnet of a very delicately constructed galvanometer, will be slightly repellant to the needle; while if even one 50-000th part of iron bo present in the copper, the needle will he sensibly attracted by it. It has only recently been discovered that the hardening of steel has great influence on its degree of expansibility. Harden a steel har to its moximum, ond it will expand to a degree which may be represeuted by 84; the same piece of steel rendered as soft as possible, will only expand to 62. ‘I'he knowledge of this peculiarity may be made serviccable in various ways in the orts. While the actiou of sea-water on steel is 29.16, and on copper 13.85, the same action on tin is represented by 1.45, and on lead by nothing, or at most but the merest trace. Thie fact, and others of the same class, have recently heen applied to tbe protection of tbe bottoms of iron and iron-plated ships. Most important discoveries are reported in alloys of aluminum, by which it is rendered quite flexible and exceedingly tough ; but little, however, is as yet positively known with regard them. It ds known, however. that aluminum produces most importont modifications in steel J / ond iron. this directinn, is the reported process of hordening copper hy the admixturo of silica, forming a silicated copper. This invention hns hsen made by Mr. Diusmors, of Sandnsky, Ohio, who has taken out a patent for the sama. It is claimed thut all necessity for oiling journals composed of this material is obviated. The Columbus aud Ciocinnoti railrond compony, it is reported, is now experimenting with it, ond if found sucessful, propose to give the inventor $10,000 mercly for its uso ou their road. Tho New York Stockholder, speaking of this invention, remarks as follows : The value of the Ohin discovery, which hos been do highly oppreciated by the railway company mentioned, cousists in its use as an ootitriction substance —as a hearing for shofta which revolve with great rapidity, for instance, railway-car axless A substunes which will form n journal, and stand, without heoting to any degree approximating fusion, the swift revolution of the shaft, is a great desiderntum, not only for railroad use, but in machinery feverally. We do not see thot it is impossible for art to make silex in combinotion with a fusible metal gerve this end. ‘the New York Centro] road is using antimony for the bearings of its car axles, ctc., and finds that they need quite infrequent lubricotion, Everybody at all conversant with steam machinery, is alive to the annoynnec aud dangers resnlting from the heating of jourools, and an invention which promises sn fuuch as the Ohio one mentioned should be cherished and tested till its value or want of value be fully proved. A Caeap axp Incomeustipte Wasn.—Pine shingles, and other rough, unpainted woodwork, often becoma covered, during our California winters, with a fine, short moss, which, in tbe long, dry seasons which follow, fe almost as easily ignited as “ puok;” aod a spork trom a cigar or chimney, falling upon such dry moss, will often kindle a flame and put a building in a blaze. Now,a cheap and incomhastible wash may he made with which to cover such work, which will not only protect the wood from the formation of the moss, which causes the rapid decay of tha wood, but which will also afford a most efficient protection from fire, under ordinary circumstances of exposura to great heat and numerous sparka. Take a sufficient quantity of good stone lime and slack it carefully in a closed box, to prevent, as far as possible, the escape of steam ; after it is thoroughly slacked, pass it through a fine seive. To every six quarts of this ‘slacked lime, add one quart of coarse salt, and one gallon of water. The mixtnre should then ba boiled and skimmed clean; and tn avery five gallons thereof, add, by slow degrees, three-fourths nf a pound of potash and four quarts of very fine sand—the finer the better. Coloring matter may be added, according to fancy. Apply with a common paint-brush. This wash, if the snnd be ground very fine, looks equally as well as ordinary paiot, and is far more durable, besides heing incombustibla, It forms a hard cement, and aa such will stop cracks in a roof or elsewhere. No moss will ever gather upon such a wash. It can find nothing to feed upon ; and wood so protected will never decay from the surface. ‘Iwo good coatings apptied to bricks, will render them utterly impervious to moisture. ‘lhe expense isa mere trifle. It is said thot boards put upon a building, without planing, if coated with this wash, will endure much longer than if planed and covered with ordinary paint, Every farmer should cover his out-buildings and all hoard fences with this wash. All tbe outside wood-work about steam mills of every character, both roof and sides, should be coyered with some incombustible and preseryative wusb. Mereors.—Every one has seen meteors shoot blazing across the sky at oight. An astronomer bas reported tbe passage of an unburoed msteor, which he eupposes was outeide the limit of the earth’s atmosphere. , It was a dark body moviog with immense rapidity, and visible ouly by coming between himself aud the moon. Meteors owe their brillianey to the heat generated by friction in their passage through the atmosphere. A meteor outside of tbe atmosphere is a dark object, except upon that side which is turned towards tha sun, when it would shine if large enough to reach our vision, with reflected light, like,the moon. Such a body passing across the disk of the Among the latest discoveries announced in. full moon, could be very distinctly seen.

The Mining and Scientific Press. 243 — AMechavical, ELEOTRIOITY AS A MOTIVE POWER. A large amount of attention iz being devoted at the present time to efforts for renering electricity ecouomically availahle ae & motive power. Gen. Count de Molin, an Itailjan nohlemop, has recently constructed and patio operation a smiall puddle-whecl hout» which he colls L’ £vectiicitie, He cmploye sixteen of Boosen’s elements tn nbtain his propelling power, which, by careful measurement, has been found to be cquol to noe man power.: The paddle-whecls are two and a half fect to diameter. If wearo not mistuken, we hove an electro magnetic engine in this city that will accomplish more work with lcss expense of material. Mr. C. L. Stewart, of Philudelphiu, recently exhibited, ot the rooms nf the Free Acudemy of New York, in the presence of o number of scientific gentlemen and prominent mechauics, an electro-magnetic motor, of quite o novel construction, which the gentlemen present considered very promising. Mr. Stewart does not yet claim to huve perfected his invention. ‘The relutive cost of the power of this machine as compared with steam, iad not been fully ascertained. ‘he Philadelphia Mining Journal, iu noticing the exhihition of this machine, says that Professor Duremus, of the Free Academy, puve some very interesting explanations and illustrations of the power of electricity, previnus to the explauation of Mr. Stewart's apparatus, and expressed the opinion that, with a suitable opparatus, clectric power may be produced cheaper than eteam power. Aside from the question of cost, there ure other manifest advantoges on the side of electricity. It is cnostantly nnd instantancously ready for use; it produces neither smoke, flame, nor noxious gases; it is perfectly clean; it invclves no’ danger from fire; it is entirely safe; it is noiseless, Should. Mr. Stewart succecd in perfecting his apparatus, it might he advantageously substituted for horse-power in the propulsion of street cars, and, in fact, for nearly all vehicles. Especially on a subterranean road euch a motive power would be invaluable. Mr, Stewart intends soon to make a public triol of his apparatus upon one of the eity railroads. A New Cement.— A late number of the London Engineer announces a new cement of great value, which is introduced under the euplionious title of “The Zopissa Iron Cement,” which, it is claimed, is capable of joining any two solid substances, however dissimilar. Wood, brick, iron, stone, or glass, can be inosepnrably united with great facility. A series of experiments, witnessed by tha Angineer, gave the following results : “ Plates of glass were firmly joined, edge to edge; ordinary bottles stuck upon the wall resisted all attcupts at eepara_tion till the stone yielded. Champagne bottles, cemented bottom to bottom, sustained a weight of two hundred ond filty pounds. ‘I'wo bricks remained joined under a tension of three hundred and twenty-five pounds, till the brick itself fractured, but the cement remained firin. Brickwork cemented with this has the solidity of a granite slab. With paper treated with this preparation in solution, the inventor has made air and water-tight tubes, ammuni. tion cases, coffins, and even constructed a house, one story and a half in hight, perfectly wind and woter-tight, which he now has on exhibition.” Of the constitution of this cement, or the expense of inanufacturing it, the £nginesr makes no intimations.” A New Atitoy.—M.,M. H. Micolon, of Puris, proposes a new alloy for the manufacture of auch metal articles ag bells, hammers, novils, rails, and non-cutting tools. ‘The alloy consists of twenty parts of iron turnings or tinwaste, eighty parts of steel, four parts of manganese, and four parts of borax; but these proportions muy be varied. When it is desired to iucreasa the tenacity of tbe alloy, two or three parts of wollram nore added. When the cupola is ready, the iron and steel are poured in, tben the manganese and borax, and the vessel is filled np with coke. THE HARRISON STEAM BOILER, The HWurrison hoiler, according to the American Artisan, ia now being quite extensively ! introduced into use, and a large establishment hos been erected in Philodelphia for its manufacture. ‘Ihe differeut depurtmenta in this estnblishment aro so arronged, that the manufucture ,ie commenced at one end ond prov ceeded with through its successivo stages until tho boiler is completed ot the other; thn iron received by railroad eotcring on the track through ona door, and passing on throagh the works, withont once returning uotil it leaves the other extremity in the form of boilers ready mode for erection. Six tous of cnstings are snid to he nade up daily into boilers, und sent awuy to fill up orders, which ore constantly increasing. This is indicative of quite an extensive demand. Why is it that this boiler hus not been brought intn use here? On the score of economy and safety, it would be far superior to the ordinury wrought irou boiler. At least one of these boilers has heen set up iu this city ; hut, we understand thot it could not be made to work; for whut reason we are not definitely informed. Our impression, however: is, that the unequal expansion of the joints and fastenings euused the hoiler to leuk so badly that it could not be used. Tbe joints, os used in the instance referred to, were faced with intervening washers of wrought iron, and the whole screwed op tigbtly on longitudinal rods of wrought iron. We perecive, by the account referred to in the Artisan, that the sectious ore now put together, in Philadelphia, by nale and female joints, which are eo carcfully turned and fitted by machinery that they are obsolutely stcam-tight, hy mere contuct of the faces of the metal. By this method the joints ore also interchangeable, so that any oue section may be fitted to another without alteration. If this boiler can he, mnde to work, why might it not be advantageously adopted upon steamships and river stcnmers, and more especially where high-pressure steamers are used ? Two hundred pounds of steam can he carried on one of these boilers with more salety than eighty or one hundred pounds on boilers of ordinary constroction ; and nw serious injury could arise from an explosion, as it could rarely occur thot more than one or twvosections could explode at once, which even then would cause scarcely ony more damage than the bursting of a tube in a tubular boiler. It may, perhaps, he well for some of our enterprising mechanics to look into this matter, and see if something practicable cannot be found in it. We cotice that Messrs. Jas. Harrison and Thomas. L. Saders have patented, in England, a modification of the Harrison hoiler, which consists in casting together a slah, of forty spheres, united hy nicks, instead of mnking such a slab of “units” of four spheres each, held together by bolts. Thus, numerous joints are nvoided. The reason for the ubove change in constrnction is given as follows: « ft ap: pears that when the priming has been violent these joints have leaked.” Our impression is that the “joints” above referred to are the face joints first used, and are not the male and female joints now employed in Philadelphia manufacture, which have only been in general use a little over one year. A Harp Cement.—Tuko iron sponge, triturate finely and mix with sand, moistened with a weak solution of muriatic acid. The iron is oxydized by acidulated water, and’ the silex forms with tbe oxyd a silicate of iron, which possesses great tenacity, and is uot affected by atmospberic changes, or by acid or alkaline liquids of a boiling temperature. This cement will unite, into a solid mass, stones, pebbles, ete., forming conglomerates impervious to moisture, and capable of being moulded into stntues, bas reliefs, ete. This process is simply an imitation of a process of nature, which is sometimes carricd on upon a large scale, in the formation of some of the hardest rocks. Tue Miwerat wealth of England has nearly doubled within the last five years. Scientific Wiseellany. LATE RESEARCHES ON METALS. Althongh science and tha knowledge of

metuls has node eteady and nmiost wonderful progress during ths pust fifty years, still it is evident thut, in the study of metals and their alloys, there is much more to be lenrned than has hitheitn been made known. Scoreely o mooth passes wilhout ths onnouucement of the discovery of some new property in some oue of the ordinory metals, or some important fuct counccted with improvemente in their monufacture. It has long becn koown thut light is transinitted through very thin sheets of nearly all the inetals; but it hos ouly quite recently been demonstrated thnt light travels through gold aud silver more rapidly than throogh a yocuum. ‘The porosity of metals ot a high temperature is also a late discovery. It is hut a short time since Veville puhlished some very interesting papers on this sulject. His experiments enabled him’to show that even platinum, when highly heated, is permeahle to yases. ‘I'he existence of this fact is cepecially important to persons engaged in the munufheture of coal gas, where iron retorts are used for distilling the coal. So complete is the permeability of iron at a hieh red heat thot an iron tube filled with bydrogen, ard heated to that degree, will lose all trace of that yas ina few hours. ‘fhis fact is important to chemists ; but more especially important is the discovery thut platinum is also permeahle, for that metal has heretofore been employed in the laboratory under the conviction that its high density and mode of manufacture completely destroyed its porosily. It is only quite recently that it has been found possible to procure ubsolutely pure inctals of any kind, or rather that we have learned that the metals previonsly considered, pure were not so. We have already, in previous numbers, alluded to the extreme diffculty of obtaining pure iron; hut few, even among scientific men, have ever seen iron in such a condition. Pure iron is a white metal, so soft that it can readily he cut with a knife. ‘he changes produced in iron by the presence of even the most minute proportions of impurities, is wonderful—more marked thao in any other metal; hence its adaptability to such a variety of purposes in the arta. Staas, in his experimental researches, has spent months of time to produce even a very minute quantity of absolutcly pure silver, lead, ete. Pure silver, or even iron, are worth much more than their weight in gold. Pure copper is not quite so difficult of attainment, nod the smallest possible impurity can be more readily detected in this than in any other metal. ‘his is done by means of the galvanometer. Perfectly pure copper, when presented to ihe magnet of a very delicately constructed galvanometer, will be slightly repellant to the needle; while if even one 50-000th part of iron bo present in the copper, the needle will he sensibly attracted by it. It has only recently been discovered that the hardening of steel has great influence on its degree of expansibility. Harden a steel har to its moximum, ond it will expand to a degree which may be represeuted by 84; the same piece of steel rendered as soft as possible, will only expand to 62. ‘I'he knowledge of this peculiarity may be made serviccable in various ways in the orts. While the actiou of sea-water on steel is 29.16, and on copper 13.85, the same action on tin is represented by 1.45, and on lead by nothing, or at most but the merest trace. Thie fact, and others of the same class, have recently heen applied to tbe protection of tbe bottoms of iron and iron-plated ships. Most important discoveries are reported in alloys of aluminum, by which it is rendered quite flexible and exceedingly tough ; but little, however, is as yet positively known with regard them. It ds known, however. that aluminum produces most importont modifications in steel J / ond iron. this directinn, is the reported process of hordening copper hy the admixturo of silica, forming a silicated copper. This invention hns hsen made by Mr. Diusmors, of Sandnsky, Ohio, who has taken out a patent for the sama. It is claimed thut all necessity for oiling journals composed of this material is obviated. The Columbus aud Ciocinnoti railrond compony, it is reported, is now experimenting with it, ond if found sucessful, propose to give the inventor $10,000 mercly for its uso ou their road. Tho New York Stockholder, speaking of this invention, remarks as follows : The value of the Ohin discovery, which hos been do highly oppreciated by the railway company mentioned, cousists in its use as an ootitriction substance —as a hearing for shofta which revolve with great rapidity, for instance, railway-car axless A substunes which will form n journal, and stand, without heoting to any degree approximating fusion, the swift revolution of the shaft, is a great desiderntum, not only for railroad use, but in machinery feverally. We do not see thot it is impossible for art to make silex in combinotion with a fusible metal gerve this end. ‘the New York Centro] road is using antimony for the bearings of its car axles, ctc., and finds that they need quite infrequent lubricotion, Everybody at all conversant with steam machinery, is alive to the annoynnec aud dangers resnlting from the heating of jourools, and an invention which promises sn fuuch as the Ohio one mentioned should be cherished and tested till its value or want of value be fully proved. A Caeap axp Incomeustipte Wasn.—Pine shingles, and other rough, unpainted woodwork, often becoma covered, during our California winters, with a fine, short moss, which, in tbe long, dry seasons which follow, fe almost as easily ignited as “ puok;” aod a spork trom a cigar or chimney, falling upon such dry moss, will often kindle a flame and put a building in a blaze. Now,a cheap and incomhastible wash may he made with which to cover such work, which will not only protect the wood from the formation of the moss, which causes the rapid decay of tha wood, but which will also afford a most efficient protection from fire, under ordinary circumstances of exposura to great heat and numerous sparka. Take a sufficient quantity of good stone lime and slack it carefully in a closed box, to prevent, as far as possible, the escape of steam ; after it is thoroughly slacked, pass it through a fine seive. To every six quarts of this ‘slacked lime, add one quart of coarse salt, and one gallon of water. The mixtnre should then ba boiled and skimmed clean; and tn avery five gallons thereof, add, by slow degrees, three-fourths nf a pound of potash and four quarts of very fine sand—the finer the better. Coloring matter may be added, according to fancy. Apply with a common paint-brush. This wash, if the snnd be ground very fine, looks equally as well as ordinary paiot, and is far more durable, besides heing incombustibla, It forms a hard cement, and aa such will stop cracks in a roof or elsewhere. No moss will ever gather upon such a wash. It can find nothing to feed upon ; and wood so protected will never decay from the surface. ‘Iwo good coatings apptied to bricks, will render them utterly impervious to moisture. ‘lhe expense isa mere trifle. It is said thot boards put upon a building, without planing, if coated with this wash, will endure much longer than if planed and covered with ordinary paint, Every farmer should cover his out-buildings and all hoard fences with this wash. All tbe outside wood-work about steam mills of every character, both roof and sides, should be coyered with some incombustible and preseryative wusb. Mereors.—Every one has seen meteors shoot blazing across the sky at oight. An astronomer bas reported tbe passage of an unburoed msteor, which he eupposes was outeide the limit of the earth’s atmosphere. , It was a dark body moviog with immense rapidity, and visible ouly by coming between himself aud the moon. Meteors owe their brillianey to the heat generated by friction in their passage through the atmosphere. A meteor outside of tbe atmosphere is a dark object, except upon that side which is turned towards tha sun, when it would shine if large enough to reach our vision, with reflected light, like,the moon. Such a body passing across the disk of the Among the latest discoveries announced in. full moon, could be very distinctly seen.