,transcriber's ,notes ,punctuation has been standardized4 ,characters in small caps have been replaced by all caps4 ,non-printable characteristics have been given the following transliteration3 ,italic text3 -- text ,this book was written in a period when many words had not become standardized in their spelling4 ,words may have multiple spelling variations or inconsistent hyphenation in the text4 ,these have been left unchanged unless indicated with a ,transcriber's ,note4 ,the symbol #8' indicates the description in parenthesis has been added to an illustration4 ,this may be needed if there is no caption or if the caption does not describe the image adequately4 ,transcriber ,notes are used when making corrections to the text or to provide additional information for the modern reader4 ,these notes are not identified in the text1 but have been accumulated in a single section at the end of the book4 ,,nearly ,,ready1 ,cloth ,gilt1 ,,price ,,five ,,shillings1 ,elaborately and ,profusely ,illustrated by ,,the ,,brothers ,,dalziel1 uniform with the ,,boy',s ,,book ,,of ,,industrial ,,information4 ,,outlines ,,of ,,creation4 ,by ,,elisha ,,noyce4 ,the object of the ,author is to give a simple1 clear1 and lucid description of the ,universe under the following divisions3-- ,the ,sky4 ,the ,earth4 ,the ,vegetable ,kingdom4 ,the ,air4 ,the ,waters4 ,the ,animal ,kingdom4 ,london3 ,,ward ,,lock1 #aeh1 ,fleet ,street4 ,illustration3 7 ,composite of several ,industrial ,scenes47 ,illustration3 7 ,illustrated ,title ,page47 ,,the ,,boy',s ,,book ,,of ,,industrial ,,information4 ,,by ,,elisha ,,noyce4 ,,illustrated ,,with ,,three ,,hundred ,,and ,,sixty-,,five ,,engravings1 ,,by ,,the ,,brothers ,,dalziel4 ,,london3 ,,ward ,,lock1 #aeh1 ,,fleet ,,street4 #aheh4 ,,preface4 ,in putting this work before the public1 the ,author has endeavoured to supply a clear and brief description of the materials1 processes1 and apparatus made use of in the various examples of industry and skill constantly before our eyes1 so that the reader may acquire a knowledge of such things1 and an interest in those1 who1 by their hard work and patient ingenuity1 supply them2 for every article and process can be made to have a value and an interest1 in proportion to the amount of knowledge we possess respecting them4 99 99 99 99 99 ,there is no attempt in this work to describe every article and process1 but such only as are most interesting and instructive4 ,all the mere trades and handicrafts--the results of which are so various1 and depend so completely upon the skill of the artisan1 that any description of their particulars would scarcely be profitable or interesting to the reader--have been avoided4 ,the illustrations of this work have been prepared with the greatest care1 and drawn from reality4 ,by the kind permission of ,lord ,panmure1 the artists were allowed to make whatever drawings were necessary in the ,arsenal at ,woolwich2 and thanks are due to many of our eminent manufacturers for similar favours with respect to their several factories and machinery4 99 99 99 99 99 ,in the first division of this work have been placed all those materials which exist in nature1 either isolated or combined1 and which have merely to be extracted or separated1 as the earths1 metals1 c4 ,under the second division1 8,manufactured ,products10 such results of manufacture as are known by the common designation 8stuff10 and are of an uniform and particular quality1 as soap1 soda1 c41 not existing in ,nature as such4 ,in the third division1 individual articles1 the result of skilled labour1 each compounded and made up of several substances1 or of particular forms4 ,in the fourth section are the processes made use of in the production of the various necessaries or elegancies of life4 ,some of these might have been placed under the second and third divisions1 but the ,author thought proper to place them here1 on account of the processes being more readily described than their results4 ,the fifth division is devoted to the most usual forms of ,apparatus and ,machinery of general application1 avoiding all mere tools and machines for specific purposes4 ,the last division is a mere outline of those important engineering works which of late have acquired an increased interest from the addition of railways and electric telegraphs to their number4 ,,introduction4 ,the inquiring mind uses all its senses to obtain some new idea1 and to apply it to some useful purpose2 it is this spirit of research that has led to all the great results in ,art and in the mechanical and chemical sciences1 which we now enjoy and admire2 but it is only by very slow degrees1 and by great perseverance1 that such results are obtained1 although the accumulation of a few years makes an enormous aggregate4 ,look back a generation or two--where was then the steam engine1 where the tall stalks which indicate the sites of complicated and ingenious manufactures8 the blacksmith then worked at his anvil1 and wrought out with his hands what he required in iron2 but what is now done with this treasure of the mine8 behold the ,leviathan and the ,britannia ,bridge1--count their thousands of tons of plate iron rolled out by machinery1 and think of the work of their removal1 the millions of rivets to fix them together1 the elevation of the one1 and the launching of the other4 ,could this be done without that machinery which has become gradually perfected by thought and perseverance8 ,visit the iron works and see the powerful 8steam hammer0 moulding into form a mass of red-hot iron1 many tons in weight2 see the powerful and beautiful contrivances for rolling into plates1 drawing into bars and wire1 or cutting up this stubborn metal1 and call it stubborn no more6 ,see the powerful 8locomotive0 carrying along the trams hundreds of tons of goods at a rate that can hardly be equalled by the bird that flies through the air on its light pinions2 and the huge steam ships which cut their rapid way across the seas1 holding in contempt those very winds upon which alone the mariner used to depend6 ,see with what rapidity and accuracy almost every kind of 8textile0 material is produced by the steam-worked loom1 and remember that these have all arisen1 with hundreds more1 from small beginnings1 and step by step4 ,nor does the mechanical genius bound the works of civilisation4 ,from studying the various properties of the elements of nature1 and the results of their combination in various proportions and under various conditions1 the chemist arrives1 not only at their uses and applications1 but obtains results before quite unthought of6 ,instance the electric telegraph1 and think how it conveys one's thoughts half round the globe before you can express an exclamation of surprise that such things can be6 ,see also the wonderful results of the photographic art1 copying the most elaborate picture1 machine1 or portrait1 in a few seconds1 and see the results of electro-deposition1 which by an invisible agent1 coats with pure gold or silver any article subjected to its action1 or produces in a mould the article itself of the most elaborate form or pattern1 and in solid metal1 extracted by this all-powerful agent from liquids which the uninformed would never believe could contain any metal at all4 ,think of the beautiful colours of our carpets1 draperies1 silks1 c4--the chemist has devised the dyes with which they are stained2 and in our chemical factories1 what tons of vitriol1 soda1 bleaching powder1 and scores of other chemical agents are daily produced4 ,all this is the result of study and perseverance4 ,neither have the ,fine ,arts been behind in contributing to civilisation1 as may be seen in the structure and decoration of our houses1 churches1 and public buildings2 in our glass and pottery ware2 paper hangings1 and other artistic designs2 in engraving and the copious illustration of our books1 saving a long and tedious description1 and often presenting to the eye forms that words could not express4 ,and now let us consider one by one the 8materials0 and processes from which all these results arise4 ,,contents4 ,,natural ,,products3 ,earths ,metals and ,alloys ,iron ,copper ,lead ,tin ,zinc ,mercury ,gold ,silver ,platinum ,nickel ,coal ,sulphur ,plaster of ,paris ,salt ,stone ,wood ,cotton ,flax ,silk ,india-rubber ,gutta-percha ,wax ,nitre ,blacklead ,spermaceti ,,manufactured ,,products3 ,sugar ,alcohol1 or ,spirit ,starch ,soap ,stearine ,soda ,wines ,vinegar ,coal ,gas ,tar ,acetic ,acid1 or ,wood ,vinegar ,varnishes ,oils ,inks ,charcoal ,cements ,coke ,gunpowder ,gun-cotton ,phosphorus ,white ,lead ,prussian ,blue ,prussiate of ,potash ,sulphate of ,iron ,sulphate of ,copper ,chloride of ,lime ,sulphuric ,acid ,leather ,glue and ,size ,parchment ,catgut ,paper ,malt ,chocolate and ,cocoa ,steel ,tin-plate1 and ,galvanised ,iron ,glass ,soda-,water ,coal-tar ,naptha ,wood ,naptha1 or ,pyroxylic ,spirit ,,products ,,of ,,skilled ,,labour3 ,pottery ,bricks and ,tiles ,tobacco-pipes ,gold-,leaf ,shot ,files ,type ,lucifer-matches ,candles ,rope ,wire ,cutlery ,nails ,screws ,pins ,needles ,tubing ,steel-pens ,,arts ,,and ,,trade ,,processes3 ,wood and ,plate ,engraving ,lithography ,printing ,photography ,bookbinding ,paper-staining ,flax ,manufacture ,glass-painting ,cotton ,manufacture ,woollen ,manufacture ,weaving ,bleaching ,calico ,printing ,dyeing ,calendering ,bread-making ,sugar ,refining ,brewing ,distillation ,gilding ,silvering ,looking ,glasses ,silver ,plating ,electro-plating and ,deposition of ,metals ,soldering and ,brazing ,the ,smelting of ,metals ,founding ,glass-blowing and ,casting ,glass ,cutting ,bricklaying ,stone-cutting ,,apparatus ,,and ,,machinery3 ,steam ,engines ,boilers ,furnaces ,bellows and ,blowing ,machines ,screw ,propellers ,anchors ,chains ,cranes ,cranks ,fire-arms and ,projectiles ,percussion ,caps ,pumps and ,fire ,engines ,valves ,wheels ,watermills ,windmills ,syphons ,stopcocks or ,taps ,filters ,presses ,stills ,blowpipes ,thermometers ,barometers ,pendulums ,ploughs ,harrows ,rollers ,mowing ,machines ,thrashing ,machines ,reaping ,machines ,drills ,,engineering ,,works3 ,railways ,electric ,telegraphs ,roads ,bridges ,tunnels ,drains ,artesian ,wells ,mines ,ships ,canals and ,locks ,,natural ,,products4 ,,earths4 ,illustration3 7 ,illustrations of37 #a4 ,,emerald4 #c4 ,,fortification ,,agate4 #e4 ,,diamond4 #b4 ,,garnet4 #d4 ,,ruby4 #f4 ,,rock ,,crystal4 ,all earths are metals in combination with oxygen3 that is to say1 they can all be separated into a metal and oxygen4 ,the chief earths used are ,alumina1 found as clay or slate2 ,lime1 found as chalk or limestone2 and ,silica1 found as sand1 flint1 or rock-crystal4 ,these1 in various proportions1 combined with some few other matters1 form1 by far1 the greatest portion of the earth we dwell on4 ,the earths1 when pure1 are all white substances1 not very heavy1 and having scarcely any of the properties of the metals from which they are derived4 ,the next frequent of the earths are ,baryta and ,strontia2 but these may be said to be useless when compared with the three former4 ,alumina1 in its various forms of clay1 is used for brick and tile-making1 and for pottery2 hardened into the form of slate1 it is much used for roofing and for making cisterns4 ,lime1 in the form of carbonate1 constitutes the best building stones1 including marble1 so valuable for ornamental carving and decoration1 and when burnt1 to separate the carbonic acid1 forms lime itself1 which is invaluable as a cement when mixed with sand2 lime1 in union with another acid 7sulphuric7 forms plaster of ,paris1 also a most useful article in the arts1 c4 ,silica1 in the form of sand1 is very extensively used for glass making1 and1 in the form of flint1 it is ground and used for pottery3 all such stones as quartz1 rock-crystal1 ,scotch pebble1 agate1 cornelian1 c4 are but various forms of ,silica1 either crystallized or deposited in layers4 ,most of the precious stones are composed of the earths in a crystalline state and colored by some foreign ingredient1 such are the emerald1 ruby1 garnet1 c4 ,the diamond is not an earth but composed of pure carbon4 ,,metals ,,and ,,alloys4 ,metals may be known from all other substances by certain properties3 they have that peculiar brilliancy1 called1 for that reason1 the 8metallic0 lustre2 they are rapidly heated1 and as rapidly cool1 hence they are said to be good conductors of heat2 they are all opaque1 and most of them very heavy2 some indeed1 as gold and platinum1 are the heaviest substances known1 being about twenty times heavier than water2 they have1 moreover1 other valuable properties such as the capability of being melted1 of being drawn out into wire1 of being beaten into thin plates1 c4 ,all metals are simple bodies2 that is to say1 they cannot be made out of other substances1 although two or more metals may be combined and be again separated1 or they may be combined with numerous other substances1 as oxygen1 and also again separated4 ,there are upwards of fifty metals known to chemists1 yet but few are used to any extent in the arts or manufactures4 ,all the metals in use for the very many purposes to which they are applied are not simple metals1 but are what are called 8alloys10 that is to say1 compounds of two or more metals4 ,the chief metals in use are-- ,,iron1 ,,mercury1 ,,copper1 ,,nickel1 ,,lead1 ,,gold1 ,,tin1 ,,silver1 ,,zinc1 ,,platinum4 ,but in the state of oxide many are used which are seldom seen in the metallic state1 such are the earths and alkalies2 and for colors1 and several other purposes1 many other preparations are in use4 ,the chief alloys1 or compound metals in use1 are1 brass1 made of copper and zinc2 pewter1 made of lead and tin2 bell metal and gun metal1 made of copper and tin2 and solder1 which is a kind of pewter1 and made of the same metals2 the silvering for looking-glasses is made of mercury and tin2 the gold and silver used for coin are not pure metals1 but alloyed with two parts of silver or copper to every twenty-two of the pure metal1 and this forms the 8standard0 gold or silver4 ,the gold used by jewellers has often a much greater proportion of alloy--for this name is given both to a compound metal and the cheaper metal made to combine with the more precious4 ,the object gained by thus alloying the coinage1 is that of rendering the metals harder1 so that they shall not suffer much loss in wearing2 thus a small quantity of copper mixed with either gold or silver1 renders them both harder1 although itself softer than either4 ,the combination of certain metals forming alloys1 is often not exactly the mean of their respective qualities1 for instance1 a small quantity of silver is sometimes fused with cast steel for penknife blades1 and although the silver is itself much softer than the steel1 yet the combination is found to be both closer in the grain and harder2 it is known as silver-steel in commerce4 ,bismuth1 although itself not very fusible1 increases the fusibility of other metals2 a combination of #b parts tin1 #c lead1 and #e bismuth1 forms a metal fusible by boiling water4 ,,iron4 ,illustration3 ,,native ,,oxide ,,of ,,iron4 ,iron stands first in usefulness of all the metals1 for railways1 bridges1 ships1 and a thousand other purposes2 it can be both cast and wrought1 having that peculiar property1 the capability of being 8welded10 that is to say1 of softening while hot to such an extent that when two pieces are made white hot and laid together1 a few blows of the hammer will cause them to unite into one piece1 and it is by means of this most useful quality that large masses of wrought iron are produced1 such1 for instance1 as anchors and cranks for steam-boats4 ,this property of welding1 and the abundance of the ores of iron1 render it one of the most useful materials supplied by nature for the various purposes of manufacture4 ,in combination with carbon it forms that hardly less useful article known by the name of steel4 ,cast ,iron has scarcely any of the metallic lustre1 and is only fitted for solid work2 it is brittle1 like steel1 without its elasticity1 and is too soft and too porous to be made into any of the numerous tools and instruments for which steel is so eminently suitable4 ,cast iron contains many impurities1 the chief of which are carbon1 sulphur1 and silica1 got from the coke whilst being smelted in contact with it1 and from the fluxes used in the process2 it is coarse in grain1 and much more fusible than wrought iron1 which is iron in a nearly pure state and can be fused only by the very highest heat capable of being produced4 ,cast iron is converted into wrought or malleable iron by being re-melted and stirred for a long time in contact with the air1 this process is called 8puddling10 its object is to get rid of all the impurities 7chiefly carbon and sulphur7 which1 by being brought into contact with the air at a high temperature1 are said to be burnt out1 that is to say1 they combine with oxygen and form carbonic and sulphurous acids4 ,after puddling1 the iron is rolled or hammered out1 folded up1 and again extended1 and as a general rule it may be said1 the more this is continued the purer and softer is the iron4 ,,copper4 ,illustration3 ,,native ,,copper4 ,copper is a reddish-coloured heavy metal1 much used for sheathing the under part of ships1 for making boilers1 c4 ,it is about eight-and-a-half times heavier than water1 and is too valuable to be used for many purposes where either iron1 tinned iron1 or zinc are applied1 but for which purposes its great durability would fit it1 as it is easily rolled out or beaten into plates1 and is not quickly acted on by the weather4 ,it is used as coin in pence1 halfpence1 and farthings2 all vessels for cooking purposes1 when made of copper1 are tinned inside to prevent the food becoming poisonous from verdigris1 which is the rust of copper1 and is very injurious4 ,copper is found chiefly combined with sulphur1 forming 8native sulphuret of copper40 ,copper melts at a full red heat4 ,,lead4 ,illustration3 ,,sulphuret ,,of ,,lead4 ,lead is a heavy metal1 of a dull blueish tint1 and very soft2 it is extensively used for covering roofs1 for cisterns1 and for pipes for conveying water1 as it is easily bent and joined1 and is not acted on by the water which passes through it4 ,lead melts at a heat below that of redness1 and1 in combination with oxygen and carbonic acid1 forms the 8white lead0 of commerce so largely used as a paint4 ,oxide of lead1 called 8litharge10 enters into the composition of flint glass1 and in combination with a larger quantity of oxygen forms 8red lead10 a substance much used in painting4 ,lead is found in many parts of ,england1 especially ,cornwall1 where many lead mines exist2 it is got from the sulphuret called 8galena10 which is lead in union with sulphur4 ,what is called 8black-lead0 is not lead at all1 but is an ore of iron1 being iron in combination with carbon4 ,lead is about eleven-and-a-half times heavier than water4 ,,tin4 ,illustration3 ,,oxide ,,of ,,tin4 ,tin is a white metal1 almost as white as silver1 it is found chiefly in ,cornwall4 ,it is a light1 soft metal1 and1 like lead1 is easily melted2 it is used chiefly for coating vessels of harder metal1 such as iron and copper4 ,it is used to mix with copper to produce bronze1 bell metal1 and gun metal1 and with lead to produce pewter1 which used to be so extensively used as table-ware before the manufacture of earthenware became general for that purpose4 ,tin does not easily tarnish or rust by exposure to the air1 hence the use of tinned iron-plate4 ,tin1 united with mercury1 forms the silvering for looking-glasses4 ,tin is about seven-and-a-half times heavier than water4 ,,zinc4 ,illustration3 ,,sulphuret ,,of ,,zinc4 ,until the last quarter of a century1 zinc was but little used1 but of late it has taken the place for many useful purposes where lead was formerly used1 principally owing to its cheapness and lightness4 ,zinc is a hard metal of a grayish colour1 not easily bent but rather brittle1 but when made nearly red hot1 it is capable both of being rolled out into sheets and being beaten into form by the hammer4 ,zinc is about six-and-three-quarter times heavier than water4 ,like many other metals1 zinc is volatile1 that is to say1 when heated to a certain extent it passes off into vapour1 and there is no doubt1 the reason that zinc was not known or used of old was that it was chiefly lost in 8smelting10 or getting it from its ores4 ,zinc is now obtained by a sort of distillation2 the ores are mixed with the flux1 c41 in a large earthen crucible or pot1 from which an iron tube passes into a vessel of water1 the lid is securely fastened on1 and as the heat is urged the zinc is driven off in vapour1 passes down the tube and condenses in the water4 ,the zinc of commerce is obtained chiefly from the ore known by the name of 8calamine stone10 which is zinc in combination with oxygen and carbonic acid4 ,a substance called 8zinc white0 has been lately introduced as a substitute for white lead1 and would certainly supersede it1 but the zinc is found to be deficient in 8body10 which means1 the power of covering anything over which it is laid-on in a thin layer1 but as zinc white does not blacken in foul air1 and white lead does1 it has a great advantage1 and it is to be hoped that some improvement in its manufacture may improve its 8body40 ,zinc is chiefly used for roofs1 gutters1 water-pipes1 cisterns1 and various vessels for holding water1 as it does not rust so easily as iron4 ,what is called 8galvanised iron10 is iron dipped into melted ,zinc in the same way that tin-plate is4 ,,mercury4 ,mercury1 or quicksilver1 is known from all other metals by being fluid at the ordinary temperature of the air4 ,this is only owing to its extreme fusibility1 for at #gb degrees below the freezing point of water1 it also becomes solid1 and may be hammered out or cut by a knife2 it is very heavy1 being about fifteen-and-a-half times that of water1 so that most of the metals will float on its surface2 it has a bright lustre and is almost as white as silver4 ,it is found both in the fluid metallic state1 and in combination with sulphur1 in which last state it is called 8cinnabar20 this is a heavy mass of a deep red color1 and when ground to powder1 of a most magnificent red1 and is the vermillion so well known as a pigment2 this vermillion is1 however1 most frequently manufactured by combining the mercury and sulphur1 both first purified1 in this way a more brilliant color is produced than can be got from the cinnabar4 ,the metal is extracted by heating the cinnabar with iron-filings or lime in a retort1 by which means the mercury distils over and the sulphur is left behind united with the iron or lime4 ,mercury is used for many purposes in the arts and sciences1 for barometers1 thermometers1 compensating pendulums for clocks1 c41 and also in the processes of water-gilding1 looking glass silvering1 and in the ,daguerreotype process4 ,the combinations of mercury with other metals are called 8amalgams40 ,,gold4 ,illustration3 ,,gold 7 ,,nugget74 ,gold is the heaviest of the metals with the exception of ,platinum1 being rather more than nineteen times heavier than water2 it is of a bright yellow color1 and is not tarnished by exposure to the air or moisture1 hence its usefulness in ornamenting frames1 cornices1 c4 ,gold is chiefly used1 in the form of coin1 as the medium of exchange2 for ornamental purposes1 such as jewellery2 for gilding1 and for staining glass1 to which it gives a beautiful ruby-red color4 ,gold coin contains about one twelfth part1 by weight1 of copper1 this is added to give it hardness and consequently cause it to lose less by wear in use4 ,gold is not dissolved by any of the pure acids1 but a mixture of hydrochloric and nitric acids will dissolve it in consequence of giving out chlorine1 an element which freely dissolves gold4 ,gold is capable of being beaten out into leaves of extreme thinness1 and also of being drawn into wire of such thinness that five hundred feet of it weigh but one grain4 ,,silver4 ,illustration3 ,,silver4 ,silver is the whitest of the metals2 it is about ten-and-a-half times heavier than water2 it does not easily tarnish by the air1 and is not converted into dross by heat continued for any length of time1 or1 in chemical language1 it is not oxydised2 it is chiefly used for coin and for ornamental purposes where its cleanliness and beauty are strong qualities to recommend it4 ,many kinds of lead ore contain silver1 and when this is in sufficiently large proportion to pay for its extraction1 the reduced lead is subjected to the flame of a furnace which is blown on to it with a strong blast1 the flame melts the lead and converts it into an oxide called 8litharge10 which is in the form of reddish scales1 and as these are formed the blast blows them off2 in this way the lead is gradually consumed1 leaving the silver with but a small quantity of lead1 this is put on to a cup made of bone ashes called a 8cupel10 hence this operation is called 8cupellation10 the heat is then raised1 and the lead which remains with the silver1 forming a liquid glass with the bone ashes1 sinks into them1 leaving the silver bright and pure4 ,silver in some districts is extracted from its ores by what is called 8amalgamation20 the finely powdered ore is mixed with water1 some cuttings of iron and quicksilver1 and turned round in a barrel for a considerable time1 when the quicksilver is drawn off through a small hole1 and is found to contain all the silver in the ore1 together with some other metals4 ,the quicksilver is got rid of1 first by pressing and then by distillation2 so that it is all recovered for a second operation4 ,what remains is separated from the other metals1 which it may have been mixed with by different processes1 according to the nature of these metals4 ,the standard silver of the ,mint is what is called #bb carats fine 7nearly71 that is to say1 #bb parts in #bd1 the two parts being copper2 this is done to harden it4 ,the silvering of looking-glasses is made of a compound of tin and mercury1 but a process for really silvering looking-glasses has been patented by ,mr4 ,drayton2 it consists of precipitating silver from its solution by means of the oil of ,cassia1 or some other volatile oil3 the process is far too expensive for general use or for large plates4 ,silver leaf is made and used in the same way that gold leaf is4 ,,platinum4 ,platinum is a metal of a white color1 and is the heaviest substance known1 being more than twenty-one times heavier than water4 ,it is capable of being welded and wrought out by the hammer like iron2 it is not acted on by any of the acids1 but1 like ,gold1 is dissolved by chlorine or a mixture of hydrochloric and nitric acid2 it does not tarnish by exposure to air1 and is extremely difficult to melt1 requiring the very highest heat that can be produced2 these qualities render it one of the most useful of the metals to the chemist1 furnishing him with retorts1 crucibles1 and evaporating dishes suitable for many purposes2 its high price1 however1 renders it not so generally used as it would otherwise be4 ,,nickel4 ,this metal is of a white color and very difficult to melt1 it is about eight times heavier than water and is chiefly obtained from the ore known as kupfer-nickel1 found very plentifully in ,germany2 this kupfer-nickel is a native arseniuret of nickel1 that is1 nickel in chemical combination with arsenic4 ,it is very difficult to separate these two metals1 but an effectual and cheap process has lately been devised to do so4 ,nickel is attracted by the magnet similar to iron but in an inferior degree4 ,till lately nickel was but little used1 but it now forms the basis of those compound metals known as nickel-silver1 ,german-silver1 and ,british-plate1 all which varieties are generally employed as an economical substitute for silver2 it is also used largely as a foundation on which to deposit pure silver by the electro-plating process1 for which purpose it is most admirably suited being very superior to copper in consequence of its color1 as the silver always wears off unequally and exposes the ground work of metal beneath4 ,german-silver is composed of copper1 nickel1 and zinc1 in various proportions4 ,nickel always forms one of the constituents of meteoric iron1 those mysterious masses called aerolites1 which sometimes fall to the earth4 ,,coal4 ,illustration3 ,,minerals 7 ,,industrial ,,scene74 ,this1 the richest product of the mine1 the well-known fuel used in almost every branch of industry as well as for warming our houses1 is got from the depths of the earth1 where it exists in certain localities forming what are called 8coal fields0 or 8basins40 ,it is the result of changes produced during many ages upon vegetable matter buried during the various convulsions which the earth has undergone1 and pressed into layers or strata of various thicknesses4 ,to raise this valuable fuel1 powerful machinery is used and deep shafts are sunk at an enormous expense4 ,coal exists in various forms3 the following are the most easily recognised3-- #a4--;,cubical coal2 shining and easily broken into squarish fragments4 ,it burns brightly4 #b4--,slate coal2 dull in color1 splits like slate4 ,burns well4 #c4--;,cannel coal2 dull color1 breaks like resin1 and somewhat resembles jet4 ,burns brilliantly1 and splits with a crackling noise when in the fire4 ,it affords the best gas4 #d4--;,glance1 or ,kilkenny coal2 steel-grey color and metallic lustre4 ,burns without flame or smoke1 somewhat like charcoal4 #e4--,lignite1 or brown coal2 is an imperfectly formed coal4 ,the quantity of coal used is rapidly increasing owing to the extensive number of steam engines used1 especially for navigation and railway transit2 and it is a problem1 not yet determined1 how long the coal existing in ,great ,britain is likely to last2 the lowest statements make it but little below a thousand years4 ,,sulphur4 ,sulphur1 also called ,brimstone1 is a natural production1 and is found either pure1 or combined with metals forming ores1 for the most part called 8pyrites10 as1 iron pyrites1 copper pyrites1 c4 ,in chemical language these compounds are called 8sulphurets0 or 8sulphides40 ,sulphur is one of the elements2 that is to say1 it is a simple body1 or one neither capable of being made nor separated into other ingredients4 ,it is crystalline1 of a bright yellow color1 very inflammable and volatile1 burns with a blue flame and gives off pungent fumes of sulphurous acid4 ,it is got pure by distillation from various substances containing it1 and in ,sicily is found nearly pure as a volcanic product4 ,sulphur is chiefly used for the manufacture of sulphuric acid and gunpowder1 and was also largely used for making matches1 but phosphorus 7a still more inflammable substance7 has almost superseded it in the manufacture of this necessary article4 ,,plaster ,,of ,,paris1 ,,or ,,gypsum4 ,plaster of ,paris is sulphate of lime--a combination of lime and sulphuric acid2 and exists abundantly in various degrees of purity2 it occurs plentifully in the locality of ,paris1 and is brought here in masses of a greenish1 pink1 or brown color4 ,to prepare the gypsum it is first made red hot1 to separate the water which it contains1 and then ground to powder of various degrees of fineness4 ,plaster of ,paris has the peculiar property of uniting with a certain quantity of water and forming a solid compound with it2 upon this property all its usefulness depends4 ,if a portion of ,plaster of ,paris be mixed with sufficient water to form a liquid of the consistence of cream1 in a few minutes it will harden and become quite set1 and as it dries1 it will harden still more1 till it is of a hardness almost equal to stone3 this useful property causes it to be much used for casting figures and ornaments2 cheap plaster figures1 c41 are generally cast hollow1 to save the plaster2 this is done by pouring into the mould a certain quantity of the plaster mixed with water1 and quickly turning the mould about so that it shall adhere and form a layer on all the inside of the mould2 when set hard1 the mould is taken to pieces and the figure finished by scraping off the marks where the mould was joined4 ,plaster of ,paris1 combined with whiting1 forms what is called by plasterers 8putty10 and is much used for ceilings1 and similar purposes4 ,,salt4 ,salt is one of the most widely spread and plentiful minerals which the earth gives for the use of man2 all the water of the ocean derives its saline taste from salt2 many springs are completely saturated and are hence called 8brine springs10 and it also exists crystallized in beds within the earth of immense thickness and extending for miles each way4 ,the salt mines of ,cheshire are the finest and most extensive in ,england1 and in some places the stratum or layer of salt is more than one hundred feet thick1 perfectly white and crystallized4 ,salt is not a simple body1 but is composed of two simple bodies or elements1 chlorine and sodium1 hence it is called by chemists the chloride of sodium1 it can be formed by putting carbonate of soda into hydro-chloric acid 7sometimes called muriatic acid17 until no more effervescence takes place1 the result will taste salt and yield pure salt on evaporation4 ,the waters of the sea are in some places evaporated by the heat of the sun in shallow hollows dug out in the beach1 this is called 8bay salt0 and is very impure2 but the chief part of the salt of commerce is procured by evaporating the waters of brine springs2 this water is pumped up into large iron cisterns placed beneath slight sheds to keep the rain off1 and having flues running beneath them1 the first impurities are thrown away1 and as evaporation goes on1 the salt crystallizes and falls to the bottom of the cistern in a fine white powder2 this is taken out with wooden shovels and placed in conical vessels with a hole in their lower part to drain off all the moisture2 it is then dried by stoves and is fit for use2 when no more salt falls down1 the impure liquor1 called 8bittern10 is drawn off and used to procure ,epsom salts from1 by mixing it with sulphuric acid4 ,the bittern contains chloride of magnesium1 and the sulphuric acid changes it into sulphate of magnesia1 which1 when purified1 forms the ,epsom salts sold by druggists4 ,about half a million tons of salt are made in ,england every year4 ,salt1 besides its general use as a condiment1 and in preserving food for storing ships1 c41 is also used for several manufacturing purposes4 ,by adding sulphuric acid and heating it1 the acid called 8hydrochloric0 is given off1 which is largely used for many purposes2 but the chief use made of salt by the manufacturing chemist is to prepare soda for cleansing and soap making4 ,,stone4 ,illustration3 ,,stone ,,quarry4 ,stone for building is chiefly of four kinds3--lime-stone1 sand-stone1 granite1 and marble4 ,slate is never used for building1 but is very suitable for roofing4 ,the most common stone is limestone1 and that brought from ,portland ,island is especially good for building-stone2 it is called ,portland stone1 and it is of this stone that ,st4 ,paul's ,cathedral is built1 and most of the other public buildings of ,london3 it is rather soft when first dug from the quarry1 but hardens with age4 ,sandstone is a very coarse kind of stone1 and is only used where not much exposed to the weather2 it consists of grains of sand adhering so firmly together as to form a stone of considerable hardness4 ,granite is a very hard stone1 and very durable2 so hard that it cannot well be carved1 and is therefore only used where durability and plain solidity are required2 ,london ,bridge and the ,euston ,square ,terminus of the ,birmingham ,railway are built of granite4 ,marble is a very fine heavy kind of limestone1 sometimes quite white1 and generally partly transparent2 the white kind is very expensive1 and is used for statuary1 that is to say1 for carving into figures1 vases1 c42 it is very durable1 but is too expensive for general use4 ,chimney-pieces1 slabs for washing-stands1 and other articles of that description1 are also made of it4 ,limestone1 marble1 and also chalk 7a soft kind of limestone71 all become changed into lime if made red hot1 hence the name1 limestone1 is often applied to all three4 ,stone quarries are those places where stone exists of a quality suitable for building purposes1 and in a situation admitting of its easy removal4 ,all stone1 with the exception of granite and marble1 exists in layers or strata as they are called1 so that the stone can be easily split in the direction of these strata or seams4 ,when a large piece of stone has to be removed1 wedges are driven in a row into these seams1 and when the stone has started1 it is notched at the sides and back1 so that in general a square piece is thus removed2 if it be not so1 it is generally made into a somewhat square before leaving the quarry1 hence the name1 derived from the ,french 8quarre40 ,granite having none of the lines of cleavage1 as they are called1 is broken by a row of wedges driven till a crack forms from one to the other4 ,slate is a clay-stone found in layers like limestone1 but much more perfect2 so much so1 indeed1 that it can be split into slices a quarter of an inch thick and one or two feet square2 these1 when sorted into sizes1 form the slates for roofing houses4 ,it has been much used of late in thick slabs1 cut by circular saws1 for making cisterns1 a purpose for which it is well adapted4 ,,wood4 ,illustration3 7 ,,loggers47 ,wood is an article of universal application2 its lightness1 strength1 and the facility with which it can be worked1 render it almost invaluable2 although in ship-building and many of its applications to house-building iron has to some extent superseded it1 yet there are so many other ways in which it is indispensable1 that it may be looked upon as one of the greatest boons to mankind4 ,there is scarcely a use to which wood may not be applied1 whether as fuel for fires1 timber for building1 furniture both useful and ornamental1 various parts of machinery1 vessels to contain wine and other fluids1 handles to instruments1 7for in cold climates and cold weather metal cannot be handled with impunity71 and indeed for all uses in which lightness1 dryness1 warmth1 and variety of form are desirable1 wood serves as an excellent material4 ,the kind of trees that produce wood fit for building and other useful purposes are those called by the botanists exogenous4 ,amongst which the pine tribe1 oak1 ash1 elm1 and beech1 stand pre-eminent2 while mahogany1 walnut1 and rosewood are chiefly used for ornamental purposes2 box-tree wood is also very useful on account of its closeness and evenness of grain2 it is the wood used by engravers4 ,wood when first cut is wet and heavy1 but1 by being exposed to the air1 it shrinks and the sap dries up in it1 it is therefore liable to swell and become damp in moist situations this is detrimental to its usefulness2 most woods therefore are improved by being soaked a long time in water1 this cleanses it from saline and extractive matters which keeps the wood damp1 but which1 when separated1 allow the wood to shrink and harden permanently1 this process is called seasoning1 the same effect may be produced by exposure to the air and rain1 it is generally resorted to when the timber is cut up into smaller pieces4 ,the structure of wood is porous1 hence its lightness1 it has also a grain which runs the whole length of the wood in circles round its centre to the surface1 one of these circles is produced every year while the tree is growing2 wood is therefore capable of being cleft in the direction of the grain by a wedge1 in this way builder's laths are made4 ,wood cannot be cleft across the grain1 but must be cut by sawing or otherwise4 ,the pine or fir tribe produce the largest and straightest timber1 but it is not so strong nor so durable as oak and many other woods4 ,some specimens of the ,araucaria ,excelsa or ,norfolk ,island pine1 have stems upwards of three hundred feet high1 and in the ,crystal ,palace is the bark of another gigantic tree the ,wellingtonia ,gigantea4 ,,cotton4 ,illustration3 ,,cotton 7 ,,plant74 ,cotton consists of the fine long hairs which grow from the seeds of several varieties of ,gossypium1 a plant belonging to the natural order of ,malvace4 ,these hairs are so long and numerous that they completely fill the pod or seed vessel2 they are very delicate1 and of the same size throughout1 and but seldom jointed1 they are each separate from the other4 ,the cotton plant is chiefly cultivated in ,america and ,india4 ,in ,india1 and some of the islands in the ,indian ,ocean1 cotton has been cultivated1 spun1 and woven into textures from time immemorial4 ,cotton fabrics were in use in ,mexico before its conquest by the ,spaniards1 and have been used in ,china for many hundred years2 its chief source now is ,america1 where more than two hundred times the quantity is grown at present than was grown there half-a-century ago2 but the internal communication brought about by railways in ,india1 may1 in all probability1 revive the cultivation of cotton in that country2 the cost of conveyance from the interior having been one of the greatest drawbacks to its exportation4 ,cotton is not only cheaper than linen 7which is woven from flax71 but has several advantages over it3 it takes dyes much better1 and produces brighter colors2 the improvements made in the machinery for spinning and weaving cotton1 have not only enabled us to match the spinners and weavers of ,india1 which1 for a long time supplied nearly the whole of ,europe1 but at the present time1 cotton cloths of ,english manufacture are exported to ,india for the purpose of clothing the natives of that country4 ,,flax4 ,illustration3 ,,flax 7 ,,plant74 ,flax is obtained from the stalks of the flax plant ,linum ,usitatissimum1 it is supposed to have been originally brought from ,egypt1 where linens have been woven from its fibres from time immemorial4 ,it is now found growing wild in this country1 and is cultivated in most parts of ,europe1 either for its stalks to make flax1 or for its seed 7linseed71 which is used for fattening cattle1 and yields an oil 7linseed oil7 much used in the making of paint4 ,the plant grows to two or three feet in height1 bears a blue flower in ,july1 and has a great hollow stem2 when gathered1 it is pulled up by the roots4 ,the fibres of flax are very long and even2 it is the inner part which yields the best fibres4 ,,silk4 ,illustration3 ,,silk 7 ,,worms74 ,silk is by far the strongest of the textile fabrics1 being nearly three times as strong as flax2 it consists of the filaments spun by the silk-worm1 ,phalna ,bombyx ,anori4 ,these filaments are always double1 proceeding from two holes in the head of the worm1 and are united by a sort of varnish which is moist and clammy when the threads proceed from the insect1 and causes them to adhere together4 ,the silk-worm in spinning1 moves the head backwards and forwards1 attaching the threads on alternate sides and all around till it is completely covered in with a ball of silk2 in this state it is called a 8coccoon40 ,the silk-worm1 like others of its class1 undergoes four changes or metamorphoses--the ,egg1 the ,grub or ,worm1 the ,chrysalis1 and the ,imago or perfect insect1 which1 in this case1 is a moth4 ,the worm spins the coccoon to defend itself from injury and cold1 but man1 taking advantage of the useful qualities possessed by these fine filaments1 spins them into his most gorgeous apparel4 ,the coccoons are unwound by placing them in a basin of warm water1 which dissolves the varnish1 and they are then slowly wound off2 formerly this was done by hand1 but now machinery is chiefly employed which winds off the silk from a bowl full of coccoons at the same time4 ,the silk is coiled into hanks or skeins1 and in this form is imported into this country2 from these hanks it is wound off on to large six-sided wheels called 8swifts10 and from these on to bobbins or reels2 it is then wound off from two or three of these bobbins on to one other bobbin1 the threads of silk being laid side by side1 and in this process a twist is given to it in one direction and two of these wound on to another receiving a twist in an opposite direction1 this forms a fine cord called 8organzine10 which is used by the silk weaver in the same way that yarn is by the cotton weaver4 ,the short and broken pieces are carded and spun like cotton1 and is called floss silk4 ,the raw silk is of a bright buff or golden yellow color1 but there are some kinds which are white4 ,,india-,,rubber4 ,india-rubber or ,caoutchouc which was1 a short time back1 used only for the very insignificant purpose of rubbing out pencil marks1 is now used for almost innumerable purposes4 ,india-rubber is the solidified juice of several trees1 such as the ,siphonia1 ,jatropha ,elastica1 ,ficus ,elastica1 c41 the juice is got by making incisions in the trunk of the trees during winter and collecting the juice1 which is caoutchouc combined with water1 in the form of a milky thick fluid1 the water is then allowed to evaporate and the ,india-rubber remains4 ,it is brought here in all sorts of shapes1 and is purified before it is fit for commercial use by washing in warm water or steaming2 it is then cut into pieces and put into a kneading machine which cuts and works it together with such rapidity that it becomes quite hot and the pieces join into one mass4 ,after having undergone every kind of torture that can be well imagined in the form of cutting1 tearing1 and squeezing1 it is finally compressed in a square cast iron mould1 where it is kept for a time1 and then is fit for any use it has to be applied to4 ,what is called vulcanized ,india-rubber is produced by incorporating it with powdered sulphur1 or some substance containing it1 as sulphuret of antimony1 or the vapour of sulphur is kneaded into the mass2 this vulcanized rubber is very elastic and does not harden by cold4 ,waterproof fabrics are made by stretching the stuff to be waterproofed on a frame1 at one end of which is a partition having a slit in it1 through which it is drawn1 after having been smeared with a solution of ,india-rubber in naptha2 the slit is so narrow that it scrapes off all superfluous caoutchouc1 it is then dried in the air4 ,,gutta-,,percha4 ,gutta-percha is a substance possessing many useful and valuable properties2 it was unknown in ,europe until within a very recent date1 though it is said to have been in common use1 for a long period previous to our discovery of its utility1 amongst the natives of the ,indian ,archipelago1 chiefly for making axe-handles4 ,it is the concrete juice of a large tree1 supposed to be the ,isonandra ,gutta1 and is brought to ,europe in irregular masses of a brown color1 and contains various impurities which are easily got rid of by working it in hot water4 ,gutta-percha possesses the desirable properties of being solid1 slightly elastic1 not brittle1 and very tough1 capable of being melted at the heat of boiling water1 and being drawn out or moulded into almost any form2 it resists the action of water and spirits1 unless very strong1 oils1 alkalies1 and weak acids1 but spirits of turpentine1 chloroform1 and naptha1 each dissolve it4 ,a substance which has so many valuable properties as these1 of course enters into a multiplicity of forms and uses4 ,,wax4 ,this useful substance is produced by bees for the purpose of building their comb1 which consists of hexagonal cells made of wax2 which substance they secrete in scales1 between the sections of the abdomen1 and draw out for building their beautiful cells4 ,when the honey is drained off from the comb1 this is washed and melted1 it then constitutes the yellow wax of commerce1 commonly called 8bee's-wax40 ,to make this into the white wax it is boiled in water1 spread out into thin layers1 and exposed to the light and air2 this is repeated until all the color has gone and the wax remains pure and white4 ,pure wax is a soft-feeling substance1 harder than tallow1 and not greasy to the touch2 it is easily melted1 and burns with a clear white flame1 hence its most general use--namely1 that of making candles2 it is not soluble in water1 but unites with oils and fats4 ,,nitre4 ,this substance1 known also in commerce by the name of saltpetre1 is brought to this country from ,india1 where in certain places1 it forms a sort of efflorescence on the soil2 this is taken off together with the surface of the soil1 and mixed with water1 which1 after all the earth has subsided holds the nitre in solution4 ,the water is then evaporated and the nitre crystallizes in six sided prisms4 ,on most parts of the continent nitre is manufactured from what are called nitre beds1 these consist of old mortar and other matters containing lime1 as the dry rubbish from old building1 c41 together with manure and other animal refuse4 ,these beds are packed up and kept from the rain for a certain time1 when a small part of the lime is found to be converted into nitrate of lime1 this is the white substance frequently seen to exude from newly built walls in the form of crystals like snow4 ,the whole mass of the nitre bed is next washed2 the water used for the first portions being poured over the next1 and so on till it is pretty rich in nitrate of lime1 this is then mixed with carbonate of potash1 which decomposes the nitrate of lime forming nitrate of potash1 7nitre71 and carbonate of lime1 7chalk72 this last settles down and leaves the solution of nitre clear1 which is evaporated1 and the nitre got pure4 ,nitre is used for making gunpowder and fireworks of different kinds1 also for curing meat1 especially pork and beef1 to which it imparts a red color2 it is also used for making nitric acid1 in the manufacture of sulphuric acid1 and as a medicine4 ,,blacklead4 ,this substance1 called by mineralogists 8plumbago0 and 8graphite10 is found in small quantities in various districts1 and in a very pure state in ,cumberland4 ,it is almost pure carbon1 having but a very slight admixture of iron2 it is used to make blacklead pencils2 for coating the surface of iron1 giving it a bright appearance and preventing it from rusting2 it is also used to prevent friction in wooden machinery1 and1 mixed with tallow1 as a lubricate for iron machinery2 blacklead1 mixed with clay1 is also used to make crucibles for various purposes1 these are especially adapted for melting glasses and enamels1 and are known in the trade as blue pots4 ,,spermaceti4 ,this substance is obtained from the oily matter contained in the head of the spermaceti whale1 ,phyceter ,macrocephales1 which consists of sperm oil and spermaceti4 ,the latter crystallizes as the mass cools1 and is afterwards purified4 ,it is white and crystalline1 is used chiefly for candles1 or mixed with oil and wax1 it forms an ointment4 ,,manufactured ,,products4 ,,sugar4 ,illustration3 7 ,,sugar ,,cane ,,field47 ,sugar1 like starch1 exists naturally formed in many vegetables1 and has to be separated from the various foreign matters with which it is combined2 the sugar used in this country is all extracted from the juice of the sugar-cane1 ,arundo ,saccharifera1 but in ,france a great portion is extracted from beet-root4 ,the raw1 or ,muscovado sugar as it is called1 is a brownish compound of small crystals of sugar held together by molasses or treacle1 which gives the sugar its color and peculiar moistness2 when pure1 sugar is quite white and capable of crystallization1 as may be seen in sugar candy1 which is crystallized sugar2 sugar1 if heated1 becomes converted into a dark brown liquid called burnt sugar or 8caramel10 this has an intensely rich color1 but scarcely any sweetness2 it is used to color wines and spirits4 ,the tendency of sugar to be converted into caramel is very great1 and the whole difficulty of sugar refining depends upon this fact1 for a solution of sugar heated is constantly changing into this substance4 ,to obtain the sugar from the sugar cane1 it is first crushed between powerful rollers1 by which all the juice is pressed out1 this is immediately clarified by boiling it strongly with a small quantity of slaked lime1 or it would speedily ferment1 it is then put into evaporating pans1 in which it is evaporated till it is ready to crystallize or granulate2 from these pans it is ladled out into a cooler1 and from thence into wooden boxes where it granulates2 the next process is called 8curing0 this consists of draining the sugar of its molasses1 for this purpose hogsheads or large broad barrels are arranged on a sloping floor1 and having several holes at their lower part with a piece of plantain leaf put into them2 through these holes the molasses runs out and is collected in a vessel for the purpose4 ,the best kinds of sugar are partly purified by a process called 8claying20 this consists in putting the sugar into conical earthen jars1 with a hole at the point which is turned downwards2 the top is piled up with a mass of wet clay1 the moisture from which slowly sinks down1 carrying with it most of the coloring matter of the sugar2 the cone of sugar is afterwards dried1 broken up1 and each part ground up separately1 as they form sugars of different value1 the point being the brownest and the base of the cone the whitest4 ,sugar is made from the beet root in the same way as from the cane1 the roots being rasped up into a pulp by a wheel with a notched edge acting against them4 ,beet-root sugar crystallizes better than cane sugar2 otherwise it is exactly like it1 and purifies as well4 ,,alcohol1 ,,or ,,spirit4 ,alcohol1 commonly called spirits of wine1 is procured from any liquid which has undergone the vinous fermentation1 such as wine and beer4 ,the spirit used in ,england is procured from a wash made by pouring boiling water upon ground malt1 as for making beer2 this1 when fermented and distilled1 produces a colorless spirit1 which1 by being again distilled at a gentle heat1 called rectifying1 produces a very strong spirit2 but even this contains some considerable quantity of water1 and to get rid of this1 for certain chemical purposes1 it is necessary to add carbonate of potash1 quick lime1 or some other ingredient greedy of water1 and again distil it4 ,brandy1 rum1 and whiskey1 are but various forms of spirit colored and flavored with different substances4 ,brandy is distilled from wine2 rum from the molasses1 a sort of treacle produced in sugar making2 and whiskey from malt4 ,the strongest brandy does not contain more than one half of its bulk of pure spirit4 ,alcohol1 when pure1 is a very limpid1 colorless fluid1 lighter than water1 in the proportion that #gib bears to #ajjj4 ,it is very volatile1 boiling at #agb deg4 of ,fahrenheit1 and highly inflammable1 it dissolves resins and volatile oils1 and is1 therefore1 used largely in perfumery4 ,the well known lavender water and eau de ,cologne1 are solutions of volatile oils of various kinds in pretty strong alcohol1 and what are called spirit-varnishes1 are most of them solutions of various kinds of resin in strong alcohol1 although some of them1 as mastic varnish1 are made with spirit of turpentine1 a volatile oil1 in place of alcohol4 ,,starch4 ,starch exists naturally in various kinds of grain1 as wheat and barley1 and in the roots and tubers of many plants1 as potatoes4 ,the process of extracting the starch1 and separating it from the other constituents of the seed or root1 consists1 essentially1 of crushing it1 and wishing out the starch with cold water2 the liquid resulting from this mode of treatment is of a milky whiteness1 and deposits starch by sediment4 ,this liquid is passed through five sieves to separate the husks and skins1 and when the starch has settled1 and the liquid fermented and become sour1 it is drawn off2 it is allowed to become sour as the gluten of the grain is more completely separated by so doing4 ,the starch is repeatedly stirred1 allowed to settle1 and the water drawn off1 till it is quite pure2 the top of the starch is scraped to separate any slime adhering1 and the pure starch dug out with wooden shovels and put in a box lined with linen1 in which the moisture drains off2 the cakes taken from these boxes are cut up into squares1 put upon bricks1 and dried by a gentle heat2 the squares are then scraped clean and packed in paper for sale1 in these packages it breaks up into pieces1 so that when they are opened1 the starch has that peculiar appearance so familiar1 and almost resembling six-sided columns4 ,arrow-root is the starch obtained from a ,west ,indian plant called ,maranta ,arundinacea4 ,cassava and ,tapioca are starches from the manioc1 and ,sago1 from the sago palm4 ,starch1 under the microscope1 appears in the form of minute globules1 and is quite insoluble in cold water1 in which it falls to the bottom1 leaving the water at the upper part quite clear2 but water that is nearly boiling 7that is to say at #afj deg4 of ,fahrenheit's thermometer1 or above71 breaks or dissolves the granules1 and the starch forms with it a sort of paste1 this is the liquid used for stiffening linen and other articles in domestic laundry4 ,the starch sold in this country is colored blueish by smalt or indigo2 but on the continent is used of its natural white color4 ,if starch be baked in an oven at the temperature of about #cjj deg4 it becomes1 to a great extent1 soluble in cold water1 forming what is called 8,british gum10 this is largely used for calico printing and other purposes2 if boiled in water under great pressure1 so that the temperature can be raised to the same degree1 it is also changed into an adhesive sort of gum--this is the substance made use of by the government authorities to spread over the backs of postage and receipt stamps to make them adhere4 ,the starch of grain during germination1 or growth1 becomes converted into sugar2 the same effect can be produced by heating starch with diluted sulphuric acid4 ,,soap4 ,illustration3 7 ,,soap ,,making47 ,illustration3 ,,cutting ,,soap4 ,illustration3 ,,coppers ,,for ,,the ,,mixing ,,process4 ,this very useful article is produced by a combination of tallow or oil with soda or potash2 with soda1 hard soap is formed2 with potash1 soft soap4 ,the yellow soap of commerce has also an addition of resin or turpentine1 and often palm oil1 these give it its yellow color and peculiar smell2 pure white soap is made by boiling a solution of soda with tallow or olive oil2 ordinary soaps are generally made by mixing a solution of the soda of commerce1 7carbonate of soda7 with quick lime1 this takes away the carbonic acid and makes the soda what is called 8caustic20 this solution is drawn off1 and kitchen stuff1 tallow1 turpentine1 and sometimes palm oil1 are added and boiled together1 until all is converted into soap1 but a large quantity of water remaining1 it is necessary to separate the soap from this1 for this purpose salt is added until the water becomes so heavy that the soap rises to the surface1 whence it is removed into moulds or frames and allowed to cool1 when it is cut into bars for sale4 ,illustration3 ,,filling ,,yellow ,,soap4 ,illustration3 ,,mottled ,,soap ,,frames4 ,soft soap is made in the same way1 using potash instead of soda1 and1 generally1 a large quantity of train-oil4 ,castile soap is pure soda soap1 and the blueish or red mottled appearance is produced by stirring in some sulphate of iron 7green vitriol72 when new it is of a blueish color1 but gets red by exposure to the air4 ,oils and fats combine with the oxides of several of the metals1 and a combination of oxide of lead with olive oil forms a firm solid substance1 or plaister1 which1 with the addition of a little resin1 is used in surgery1 and when spread upon linen or calico1 forms the common adhesive plaister4 ,oils and fats all consist of a combination of organic acids1 7stearic1 oleic1 and margaric71 with glycerine4 ,when these fats are boiled with soda1 potash1 or metallic oxides1 a combination of the oxide and fatty acid takes place1 and this constitutes soap4 ,the glycerine is then set free1 and1 when purified1 forms a sweet1 oily1 colorless fluid1 very similar to syrup1 but not so sweet2 it has lately been used for several purposes1 especially as a remedy for chapped hands2 a soap called 8glycerine soap10 has lately been used for the same purpose2 it is a soap made without separating the glycerine4 ,illustration3 ,,machine ,,for ,,cutting ,,soap ,,in ,,bars4 ,the above illustration represents an ingenious contrivance for the purpose of cutting soap4 ,,stearine4 ,the ,stearine ,candles1 so much in use of late1 are made of what chemists call 8stearic acid40 ,it is extracted from tallow by the following process3--,the fat is first melted1 then boiled with water and quick lime2 the lime forms a solid insoluble soap with the stearic acid of the fat4 ,this1 when cold1 is dug out of the cistern and separated from the watery parts2 it is then melted in a wooden cistern by means of perforated iron pipes1 through which steam passes2 the steam not only melts it1 but condenses and runs to the bottom1 thoroughly washing it2 it is again allowed to cool1 separated when it is mixed1 stirred well with sulphuric acid and a large quantity of water1 and allowed to settle4 ,this separates all the lime1 which settles to the bottom1 leaving the stearine floating on the top1 from whence1 when cold1 it is taken and again well washed with steam4 ,the mass1 after cooling1 is cut into shavings by a machine consisting of a wheel1 having knives attached to its edge2 the shavings are put into hair-cloth bags and subjected to the most powerful pressure by means of the hydraulic press2 each hair-cloth bag having a warm iron plate interposed between it and the next bag4 ,the oily parts of the mass are1 by these means1 all pressed out2 the remainder is again cut up and a second time pressed1 leaving the pure stearine1 white and crystalline like spermaceti4 ,,soda4 ,illustration3 7 ,,soda ,,furnace47 ,the ,soda of commerce is a carbonate of soda1 and it is made from sea salt4 ,it is used in large quantities for the general purposes of washing and cleansing1 and very extensively in bleaching and soap making4 ,soda occurs in two forms--soda ash and in crystals2 the first is the crude soda before crystallization4 ,to make soda1 oil of vitriol 7sulphuric acid7 is poured1 by degrees1 on a layer of sea salt1 in a sort of funnel connected with a tall chimney2 on the addition of the vitriol1 copious fumes of the hydrochloric acid are given off2 this is the acid formerly called spirit of salt4 ,when the furnace is heated and all the acid driven off1 the dried residue is taken out1 it is sulphate of soda4 ,it was formerly the custom to allow the hydrochloric acid to pass up a very tall chimney so that it may be dispersed in the air2 but such an injurious effect was produced on the surrounding vegetation that this could no longer be allowed2 the plan adopted was1 to cause the acid to be condensed by filling the chimney with coke1 and causing water to trickle through it2 the acid vapours1 coming into contact with this porous wet surface1 is condensed into a liquid1 which runs down into a cistern placed to receive it4 ,the sulphate of soda1 when taken from the furnace and cooled1 is next ground in a mill with rather more than its weight of chalk1 and about half its weight of coal4 ,this mixture is placed in a furnace and raised to a sufficient heat to partly fuse it1 during which time it is stirred about2 the black mass which results is called by the workmen 8black ball40 ,it is taken out and put into a cistern2 water is then poured over it1 and after stirring1 it is drained off and evaporated to a dry mass2 this is impure soda4 ,it is mixed with coal-dust1 again burnt1 again washed and evaporated1 by this second process the soda ash is produced1 which1 being dissolved1 filtered and evaporated1 produces large crystals of soda4 ,the large quantity of hydrochloric acid produced in the first part of the process1 is used in the of making chloric of lime4 ,a few years back1 soda was got from the ashes of the plant called 8salsola soda10 and sold in the form of an impure carbonate called 8barilla40 ,,wines4 ,illustration3 ,,wine ,,making4 ,wine is made from the juice of grapes4 ,when the grapes are ripe1 they are gathered and at once put into a press1 by which all the juice is squeezed out1 and the skins1 stalks1 and seeds left in the press4 ,this juice1 which is called 8must10 is allowed to ferment1 which it does of its own accord1 in the countries where grapes most abound1 and at the season of the year when they are gathered1 without the addition of yeast or other ferment2 in a few days nearly all the sugary matter contained in the 8must0 becomes converted into spirit1 and it has now the pungent taste of wine2 7if the wine is allowed to ferment too long1 it is very apt to become sour71 the wine is now put into casks and kept for a time1 during which a slow fermentation goes on1 and that substance1 which is called 8tartar10 is deposited in the form of a thick crust of an acidulus taste and brown color2 when purified till it is quite white1 it forms the cream of tartar of the druggists' shop4 ,the color of wine depends upon the color of the grapes used1 whether white or black4 ,wine1 at a general average1 contains about #bj per cent4 of spirit or alcohol2 when port wine is put into bottles1 a slow fermentation continues to go on1 and a crust of tartar is deposited similar to that described above1 and it is the separation of this tartar which causes port wine to improve by age4 ,what are called ,british wines1 are liquids mostly made by fermenting the juice of the fruits whose name they bear1 as currant wine1 gooseberry wine1 c42 but as the climate of this country is not favorable to the growth of grapes1 or the spontaneous fermentation of their juice1 the grape wine of ,england is very inferior to the foreign4 ,the juice of any fruit required to make wine of1 has to be fermented artificially2 this is generally done by making it slightly warm1 and floating on the surface a piece of bread soaked with yeast2 the wines thus produced are very apt to become sour1 and it is generally necessary to add brandy to preserve them4 ,many of the ,british wines sold in ,london are made of an impure weak spirit called 8faints10 sweetened and flavored with various substances1 as ginger1 orange-peel1 c4 and sell for ginger or orange wine4 ,,vinegar4 ,illustration3 7 ,,vinegar ,,fermentation ,,yard47 ,vinegar is produced by fermenting and exposing to the air any liquor which contains sugar1 such as wine1 infusion of malt1 cyder1 c42 by the addition of yeast1 this sets up a fermentation1 by means of which the sugar in any of these liquors is converted1 first into spirit1 and afterwards into vinegar2 this contains a certain quantity of acetic acid1 which makes the vinegar sour4 ,in warm countries1 vinegar is made by simply exposing the poorer kinds of wine to the sun's rays1 when they ferment and become sour4 ,in ,england1 all the vinegar produced is made by fermenting wort made of malt1 this is fermented for three or four days1 and is then put into casks1 with the bunghole left open for several weeks1 or until it is thoroughly sour4 ,in ordinary vinegar1 there is about five or six parts only in the hundred of real acetic acid1 but this acid1 when pure1 is so strong as to blister the skin when dropped on it2 it is often extracted from vinegar for chemical purposes1 and to smell too2 for when scented1 it constitutes aromatic vinegar4 ,vinegar1 besides acid and water1 contains a little unchanged spirit1 much coloring matter1 and some mucilage4 ,illustration3 ,,boiler ,,or ,,copper4 ,illustration3 ,,cooling ,,apparatus4 ,vinegar is chiefly used as a condiment1 and for making pickles1 and has considerable powers of preserving vegetable or animal substances2 if common vinegar be distilled1 a weak colorless acid comes over1 commonly known as white or distilled vinegar4 ,it is a common thing to sprinkle a sick room with vinegar1 under the impression that it has disinfecting properties1 but this is an error2 although the odour is very refreshing4 ,vinegar has1 of late1 been made by means of the vinegar plant1 which is a fungus1 causing a species of slow fermentation1 and converting the sugar or treacle used into acetic acid4 ,illustration3 ,,filling ,,casks4 ,the heading of this section gives a good idea of the large scale on which vinegar is made2 being an accurate representation of the extensive works of ,messrs4 ,beaufoy ,co4 at ,lambeth4 ,,coal ,,gas4 ,illustration3 7 ,,coal ,,gas ,,distillery47 ,illustration3 ,,section ,,of ,,retort4 ,illustration3 ,,fig4 #a4 7 ,,retort ,,furnace47 ,illustration3 ,,fig4 #b4 7 ,,receiver ,,tube47 ,illustration3 ,,fig4 #c4 7 ,,condenser47 ,illustration3 ,,fig4 #d4 7 ,,reservoir47 ,illustration3 ,,fig4 #e4 7 ,,gasometer47 ,gas1 for lighting1 is made from coal1 by subjecting it to heat in iron tubes and collecting and purifying the gas which is produced2 the following is a summary of the process3--,the vessels in which the coal is put are called 8retorts10 they are six or seven feet long1 one-and-a-half broad1 and one high1 generally fitted up six to a furnace1 in such a way that the flame may entirely surround them 7see fig4 #a72 from each retort an iron tube passes1 and these all dip into a large horizontal tube1 reaching nearly to its bottom 7fig4 #b71 this is the receiver for all the gas from the retorts2 it is connected with a pit for tar and ammonical liquor1 which copiously condenses from the hot newly-formed gas4 ,the object of causing the tubes to dip nearly to the bottom of the receiver is1 that the fluid in it may close the end of each tube1 and so prevent the gas returning when any of the retorts are opened for a fresh supply of coal2 from the receiver1 the gas passes by tubes bent up and down inside of a great cistern of water 7fig4 #c7 kept cold by a constant change of its contents2 this is the condenser1 it causes the separation of all the tar and ammonia that remain2 but the gas is still contaminated with sulphur1 and this is got rid of by causing it to pass into a broad iron cylinder perforated with holes and dipping into a reservoir of lime and water mixed together and stirred about with a machine contrived for the purpose2 the gas enters this lime mixture in hundreds of bubbles through the holes1 and the sulphur the gas contains is attracted by the lime with which it unites4 ,the gas now rises to the top of this reservoir1 which is1 of course1 air tight1 and from thence passes for use to the gasometer2 this is the store-house where the gas is kept to supply the service pipes b1 c1 under the streets4 ,the gasometer is made of plates of iron rivetted together4 ,the lower part of this cylinder 7see figs4 #d and #e7 is received into a circular deep channel cut in the ground 7b b1 fig4 #e7 and filled with water1 so that the gasometer d1 which is suspended and balanced by means of the chains and weights e e1 may be raised or depressed at pleasure4 ,when the gasometer is quite down1 the inside of its top1 a1 rests on the ground2 when the gas enters1 it raises it up till the lower edge is but a few inches below the water1 and is prevented from rising higher by frames which support it2 when some of the weights1 d d1 are removed1 the huge cylinder1 a1 slowly sinks down and forces the gas through the tubes1 c c1 to be burnt by thousands of consumers4 ,about four cubic feet of gas is produced from every pound of coal used2 the gas is lighter than air in the proportion of #fej to #ajjj1 and it is owing to this lightness that balloons ascend when filled with it1 not from any peculiar power it has of ascending1 but because the air1 being heavier1 presses downwards and forces it up4 ,when gas is mixed with air it becomes very explosive1 and when any escape is suspected in a room1 the windows of the room should be opened at the top1 and the door also opened1 before any light is introduced2 a few minutes will then suffice to ensure safety4 ,one ton of good coal produces-- #a ,chaldron of ,coke1 weighing #adid lbs4 #ab ,gallons of ,tar 0 #ace 0 #ab ,gallons ,ammoniacal liquor #ajj 0 #iejj ,cubic feet of ,gas1 weighing #bia 0 ,loss 7chiefly water7 0 #bbj 0 -------- #bbdj lbs4 ,a cubic foot of gas weighs #ead and a-half grains4 ,,tar4 ,illustration3 7 ,,tar ,,factory47 ,tar is one of the results left in the distillation both of wood and coal2 in places where wood is plentiful and tar in request1 it is produced by burning the wood for that purpose2 and in some of the pits in which charcoal is produced1 an arrangement is made to collect the tar also4 ,coal-tar and wood-tar are different in some respects1 and are both distilled to procure the napthas which bear the respective names4 ,from wood-tar1 creaste is also extracted1 and it is this substance which gives the peculiar tarry flavor to provisions cured or preserved by being smoked over wood fires1 such as ham1 bacon1 or herrings4 ,tar is used as a sort of paint for covering wood-work and cordage1 when much exposed to wet1 which it resists better than anything else at the same price2 but the tar chiefly used for these purposes1 is that produced by burning fir or deal wood and condensing the tar in a pit below the stack of wood1 it is called ,stockholm tar1 as it comes chiefly from that place4 ,,acetic ,,acid1 ,,or ,,wood ,,vinegar4 ,acetic acid forms a considerable article of commerce4 ,it is not only used in medicine and the culinary art1 but is extensively employed in forming acetate of iron for dyeing and calico printing4 ,to prepare it1 large iron cylinders1 about eight feet long and three in diameter1 are embedded in brickwork in a row1 and in such a manner that furnaces placed below may heat them red-hot2 these cylinders have a tube leading from each into a main tube1 where the liquid products from each cylinder are received for condensation2 the other end of the cylinder has a plate of iron fitting closely to it4 ,the cylinders are filled with logs of wood1 either oak1 beech1 birch1 or ash1 the door is closely fastened and the joints smeared with clay2 the fires are now lighted and kept up all day1 till the cylinders are red-hot2 at night they are allowed to cool4 ,about seven or eight hundred weight of wood is put into each cylinder4 ,in the morning1 the charcoal1 into which the wood is now converted1 is withdrawn1 and a fresh charge supplied2 from this charge of wood about thirty or forty gallons of liquid is condensed in the main tube from each cylinder1 the remainder being charcoal and gases which pass off2 the liquid is acid1 brown1 and very offensive1 and contains acetic acid1 tar1 and several other ingredients1 among which may be named creasote2 it is from this source all the creasote1 so famous for the cure of toothache1 is obtained4 ,the next process is to purify this liquid2 it is first distilled1 and this separates much tar1 it is then mixed with lime1 evaporated to dryness1 and heated to expel the remaining tar and other impurities2 it is next mixed with sulphate of soda and water and the whole stirred together1 the soda1 now in unison with the acetic acid1 is washed out from the lime and strained quite clear2 it is afterwards evaporated till it crystallizes1 and vitriol 7sulphuric acid7 then added2 finally1 the acetic acid is distilled over1 and the acid left in unison with the soda1 forming sulphate of soda1 to be used in a similar process for the next batch of acid2 the acetic acid is now quite colorless1 transparent1 and very sour1 possessing a fragrant and agreeable smell4 ,this acid is not pure acetic acid1 but contains a considerable quantity of water4 ,the acetic acid of commerce1 mixed with seven times its bulk of water1 forms an acid of about the strength of malt vinegar1 perfectly wholesome1 and1 to many1 more agreeable as a condiment4 ,pure acetic acid may be made by mixing dry acetate of potash with oil of vitriol in a retort1 and distilling the acetic acid into a very cold receiver2 this1 when flavored with various volatile oils1 forms the aromatic vinegar sold by druggists4 ,it is a very strong acid1 and if applied to the skin will quickly blister it4 ,,varnishes4 ,varnishes are solutions of various resinous substances that will dry with a bright surface on exposure to the air4 ,they are used to protect different substances from the action of the atmosphere1 and to give them an elegant bright surface2 woods and painted work are the chief things varnished2 metals are coated with a kind of varnish called 8lacquer10 this is to prevent the bright surface of the metal from being dulled by the air or damp1 and to give an artificial appearance to some metals2 tin1 for instance1 if lacquered with yellow lacquer1 acquires somewhat the appearance of brass4 ,mastic varnish is the varnish generally used for paper and pictures2 it is made by dissolving gum mastic in oil of turpentine4 ,copal varnish is that most generally used for carriages and wood1 it is made by adding boiled linseed oil to melted copal1 and afterwards thinning it with oil of turpentine4 ,a common varnish1 fit for many purposes1 may be made by adding common resin to oil of turpentine1 and warming it till dissolved4 ,lacquers are made by dissolving shellac and various other gums in strong spirits of wine1 and in some cases coloring it1 either yellow1 by means of gamboge1 or red1 by dragon's blood 7a kind of resin74 ,french polish is nearly the same as lacquer1 but the mode of applying it is different2 the grain of the wood is first filled up by means of drying oil and chalk rubbed in1 when this becomes thoroughly dry1 a rubber of flannel is covered by a piece or two of clean old linen1 and some of the polish put on it1 just enough to moisten it1 and then a little oil1 this is slowly rubbed round and round1 the varnish adhering to the wood1 and the oil preventing the rubber sticking to it1 and at the same time1 polishing the surface of the varnish as it dries4 ,this process requires a good deal of art to produce a perfect surface4 ,old work1 before being varnished with any varnish that contains oil 7as copal varnish71 should be thoroughly freed from grease or greasy matter1 or the varnish will never dry4 ,good varnish should dry in twenty-four hours so that dust will not adhere to it4 ,,oils4 ,illustration3 ,,pressing ,,linseed ,,for ,,oil4 ,oils1 whether animal or vegetable1 have pretty much the same properties4 ,the vegetable oils are got by crushing and pressing certain seeds1 as linseed2 the animal oils are obtained chiefly from the whale and seal tribe1 or from fish1 as the cod and sturgeon4 ,they are viscid and of a pale yellow color1 lighter than water1 and therefore float upon it1 and are very combustible4 ,oils are used for a multiplicity of purposes3 for burning in lamps1 for making paints and varnishes1 preventing the friction of machinery1 in making soap1 and numerous other processes4 ,oils are generally divided into fixed and volatile oils2 as an example of the first1 linseed oil may be selected2 of the last1 oil of lavender4 ,some of the fixed oils are called drying oils1 and it is this kind that are used for varnish making2 as linseed oil possesses the properties of this class very perfectly1 it may serve as a description of all4 ,linseed oil has the power of drying when spread out in a thin layer1 becoming of a resinous consistence like varnish1 and upon this quality depends the drying powers of paint1 for the other non-drying oils1 as olive oil1 may be exposed to the air for months without drying at all2 the drying powers of linseed oil are greatly increased by boiling it with litharge 7oxide of lead74 ,this forms the drying or boiled oil used in painting1 and is employed in making varnishes1 printers' ink1 and for other purposes4 ,oiled silk is formed by brushing silk over with this oil and exposing it to the air till it is dry2 this oiled silk is the same that is used for sponge-bags and bathing-caps4 ,of the non-drying oils1 the chief are those used for burning in lamps1 as sperm oil4 ,salad oil is expressed from the olive1 and is called olive oil4 ,of the volatile oils1 the most useful is oil of turpentine1 commonly called spirit of turpentine2 it is got by distilling common turpentine 7the concrete juice of trees of the fir and pine tribe71 it has a strong odour1 is very inflammable1 and is volatile1 that is to say1 if spread out1 will evaporate1 leaving nothing behind2 this oil is capable of mixing with drying oils1 and it not only increases their drying powers1 but1 by thinning them1 makes them more applicable to many purposes4 ,oil of turpentine dissolves resin and many resinous substances1 and forms useful varnishes with them4 ,mastic varnish is mastic dissolved in oil of turpentine2 it is the varnish always used for varnishing pictures4 ,many of the volatile oils are used as perfumes1 and the odour of plants and flowers depends upon the volatile oil which evaporates from them1 as lavender1 cloves1 and others4 ,peppermint water1 dill water1 and cinnamon water are produced by distilling water mixed with the substances1 and is simply water containing a small quantity of the volatile oil of these substances in solution2 but eau-de-,cologne and lavender water1 although called 8waters10 are mixtures of volatile oils and spirit of wine1 and contain no more water than is comprehended in the spirit used4 ,,inks4 ,inks are fluids of various kinds suitable for writing with pens4 ,the chief inks in use are black1 blue1 and red writing inks1 and indelible or marking ink1 intended for marking linen which has to be washed4 ,indian ink is not used as an ink1 properly so called4 ,all the black inks in use are composed of green vitriol 7sulphate of iron71 in union with some astringent vegetable matter1 the best is the gall-nut1 although1 for cheapness1 logwood and oak bark have each been used4 ,an excellent black ink may be made by putting into a gallon stone bottle twelve ounces of bruised galls1 six ounces of green vitriol1 and six of common gum1 and filling up the bottle with rain water1 this should be kept three or four weeks before using1 shaking the bottle from time to time4 ,blue ink has lately been much used1 it is made by dissolving newly-formed ,prussian blue in a solution of oxalic acid4 ,to make it1 dissolve some yellow prussiate of potash in water in one vessel1 and some sulphate of iron in another1 adding a few drops of nitric acid to the sulphate of iron2 now mix the two liquids1 and a magnificent blue color will appear in the form of a light sediment2 this is to be put upon a paper filter1 and well washed by pouring over it warm water and allowing it to run through2 a warm solution of oxalic acid should now be mixed with it1 and the ,prussian blue will dissolve into a bright blue ink4 ,red ink is made by boiling chips or raspings of ,brazil wood in vinegar1 and adding a little alum and gum2 it keeps well1 and is of a good color4 ,a red ink of more beautiful appearance1 but not so durable1 may be made by dissolving a few grains of carmine in two or three tea-spoonfuls of spirit of hartshorn4 ,marking ink is made by dissolving nitrate of silver in water1 and then adding some solution of ammonia1 a little gum water1 and some ,indian ink to color it4 ,printers' ink is made by grinding drying oil with lamp-black4 ,,charcoal4 ,illustration3 7 ,,charcoal ,,ovens47 ,charcoal is made by burning wood in such a manner that but little air shall be admitted during the operation1 that is to say1 only sufficient to keep up the combustion of the more easily destroyed parts of the wood1 leaving a black residue called charcoal4 ,the best charcoal is made when the wood is quite excluded from the air1 as in making acetic acid1 but where large quantities of charcoal are used for common fuel1 as in ,france1 of course this process is too expensive4 ,the usual way is to pile up billets of wood and cover the whole with turf2 when fired1 the wood consumes gradually and the charcoal is left behind4 ,charcoal is light and porous1 and of a shining black color2 it weighs about one quarter as much as the wood used1 and burns without flame or smoke1 giving out a strong heat4 ,when charcoal burns1 it combines with part of the air1 and is converted into a gas called carbonic acid1 which1 although invisible1 is much heavier than air1 and is a deadly poison2 it is therefore necessary1 where charcoal is burning1 to always have some opening at the bottom of the room4 ,many fatal accidents have arisen from people sleeping in a small room with a pot of burning charcoal1 and no outlet for the poisonous vapour but the chimney1 up which it will not pass on account of its weight4 ,charcoal enters into the composition of gunpowder1 and is used for several other purposes4 ,it is an excellent sweetener of foul water1 and a few pieces should always be kept in the top of the filter when the water has any bad odour1 or in the cistern or butt1 where a filter is not used2 powdered charcoal has also the power of taking away the color of many liquids1 as well as the bad smell2 vinegar1 if warmed with powdered charcoal1 and then strained1 will be almost colorless4 ,water butts are sometimes burnt or charred inside1 that the water may be the better preserved in them4 ,chemically considered1 charcoal consists of carbon with a certain amount of earthy matter 7the ashes or earthy part of the wood from which it was made71 but these ashes may be easily removed by maceration in an acid2 the charcoal then remains unaltered in appearance and consists of carbon1 but its structure is exceedingly porous4 ,,cements4 ,in various processes1 cements of different descriptions are required for a variety of purposes4 ,the common cement used in building1 which is called mortar1 is made of sand and quicklime mixed with water4 ,roman and ,portland cements consist of certain kinds of clay burnt and ground4 ,plaster of ,paris forms a useful cement1 it is to be mixed with water to the consistence of cream1 and it hardens in a few minutes4 ,glue is an invaluable cement for wood and many other purposes1 it also joins any kind of broken glass or china that will not have to be subjected to much wetting4 ,shellac dissolved in spirit is a useful cement2 and isinglass1 dissolved in weak spirit1 and having some gum ammonicum added to it1 forms the 8diamond cement0 for uniting china4 ,china and glass which require to be much wetted1 are best united by being made very hot and having the broken edges rubbed with a piece of shellac1 this melts on them1 and forms1 while hot1 a sort of cement2 if they be immediately applied and pressed firmly and accurately together1 and then permitted slowly to cool1 they will unite so as to be almost as strong as before breaking4 ,,coke4 ,illustration3 7 ,,coke ,,ovens47 ,coke is produced by the partial burning of coal1 in the same way that charcoal is from wood4 ,the great source of coke is the gas manufactory1 where it is sold in large quantities1 being the result left in the retorts after the gas has all been driven off2 but the consumption of coke by locomotive engines1 c41 where coal would not be admissible on account of the smoke produced1 has become so great that it is necessary to burn coals for its production2 this is done by a range of ovens fitted up for that purpose1 having iron doors which can be closed to any extent required so as to regulate the draught of air4 ,dr4 ,ure gives the following in his account of the coke ovens belonging to the ,london and ,north ,western ,railway ,company3--8,an excellent range of furnaces for making a superior article of coke for the service of the locomotive engines of the ,london and ,birmingham ,railway ,company1 has been erected at the ,camden ,town ,station1 consisting of eighteen ovens1 in two lines1 the whole discharging their products of combustion into a horizontal flue which terminates in a chimney-stalk one hundred and fifteen feet high4 ,each alternate oven is charged1 between eight and ten o'clock every morning1 with three-and-a-hall tons of good coals1 a wisp of straw is thrown in on the top of the heap1 which takes fire by the radiation from the dome1 which is in a state of dull ignition from the preceding operation1 and inflames the smoke then rising from the surface by the reaction of the hot sides and bottom upon the body of the fuel1 in this way the smoke is consumed at the very commencement of the process1 when it would otherwise be most abundant4 ,the coke being perfectly freed from all fuliginous and volatile matters by a calcination of upwards of forty hours1 is cooled down to moderate ignition by sliding in the dampers and sliding up the doors1 which had been partially closed during the latter part of the process4 ,it is now observed to form prismatic concretions1 somewhat like a columnar mass of basalt4 ,these are loosened by means of iron bars1 lifted out upon shovels furnished with long iron shanks1 which are poised upon swung chains with hooked ends1 and the lumps are thrown upon the pavement1 to be extinguished by sprinkling water upon them from the rose of a watering can1 or they may be transferred into a large chest of sheet iron set on wheels1 and then covered up4 ,good coals1 thus treated1 yield eighty per cent4 of an excellent1 compact1 glistening coke1 weighing fourteen cwt4 per chaldron40 ,illustration3 7 ,,oven ,,tools47 ,coke burns without smoke1 and not so rapidly by far as charcoal1 it is1 moreover1 considerably cheaper than that article is4 ,,gunpowder4 ,gunpowder is a mixture of nitre1 sulphur1 and charcoal1 and the more completely they are mixed1 the more finely ground1 and the purer they are1 the more perfect will be the gunpowder4 ,the proportions used of these ingredients differ slightly in different powder mills2 but the average is about seventy-four parts nitre1 ten sulphur1 and fourteen charcoal1 by weight2 the sulphur and nitre can easily be completely purified1 but the charcoal differs very much in almost every specimen1 and charcoal that has been burnt long ago and exposed to the air and moisture is almost unfit for the purpose1 that charcoal which has the least ash when burnt is found to be the best1 and the charcoal which has been made in iron cylinders1 is better than that made in the usual way1 when each of the ingredients are separately powdered and sifted through a kind of sieve of silk called a bolting machine 7such as is used in dressing flour71 they are mixed in the proper proportions and taken to the mill1 where they are moistened with water and ground to a smooth paste1 this is pressed hard and then broken up into pieces which are put into a copper sieve1 the bottom of which is perforated with small hole2 a flat wooden ball is put into each sieve with the pieces of damp powder1 and the sieves are all put into a circular motion by machinery1 this causes the wooden ball to turn round in the sieve and so rub the damp powder through the little holes2 it is collected below in small grains or 8corns10 this process is called 8corning10 this is now dried1 and then put into a 8reel0 7a sort of barrel which turns round7 and the grains1 by rubbing against each other1 become smoothed on the surface2 the dust is now removed by a sieve1 too fine to let the grains through2 the powder is now fit for use4 ,gunpowder was first known in ,england about five hundred years ago4 ,it is not only used to discharge firearms1 but in the more peaceful occupations of quarrying stone1 mining1 and to get rid of rocks both below and above water2 these processes are called 8blasting40 ,,gun ,,cotton4 ,to prepare gun cotton1 make a mixture of three parts sulphuric acid and one part nitric acid2 when this has cooled 7for it becomes hot on mixing71 put into it some cotton wool1 and let it be stirred about with a glass rod1 then taken out1 and all the superfluous acid strained from it2 it is then to be covered up for an hour or so4 ,it should now be thoroughly washed in cold water1 so that all the acid be removed2 to ensure this completely1 let it be afterwards washed in a very weak solution of potash1 and then dried by a very gentle heat1 produced by either steam or hot water2 when dry1 soak it in a solution of nitre and dry it again4 ,it is now so explosive that great care is required in its management1 being about three times as explosive as gunpowder4 ,,phosphorus4 ,this substance1 since the general use of lucifer-matches1 has become an important article of manufacture2 whereas1 but a few years ago1 it was a mere chemical curiosity4 ,it is prepared by mixing bone ashes with sulphuric acid1 straining off the liquid part1 and evaporating it to a syrupy consistence2 with this1 about a quarter of its weight of powdered charcoal is mixed1 and the whole stirred and evaporated to a dry powder2 this is put into earthenware retorts1 which are connected by copper tubes to receivers filled with water2 the retorts are raised to a white heat and maintained at this high temperature as long as any phosphorous passes into the receivers1 the water in which is kept warm1 so that the phosphorous melts and runs to the bottom1 from whence it is taken and strained through chamois leather bags1 under warm water1 and then cast in glass tubes into sticks4 ,phosphorous is of a whitish color1 like wax1 is easily melted1 readily takes fire even by slight friction1 and1 in the air1 gives off fumes which in the dark appear luminous4 ,it is chiefly used in the manufacture of lucifer matches1 and1 mixed with flour1 butter1 or sugar1 is used to poison rats1 mice1 and other vermin1 under the name of 8phosphorous paste40 ,phosphorous is poison1 and most dangerous stuff to handle1 minute particles often getting under the nails and causing painful sores4 ,,white ,,lead4 ,illustration3 ,,white ,,lead ,,bed4 ,illustration3 ,,fig4 #a4 7 ,,lead ,,grate47 ,white ,lead is used in very large quantities by painters1 not only as white paint1 but to mix with and qualify every shade of color1 and to give body to them4 ,it is prepared by different processes1 and several patents have been taken out for improvements in its manufacture2 but the most usual1 and1 perhaps1 the best process1 is as follows3--,a layer of spent tan 7from the tanner's pits7 is spread out three or four feet thick1 and in it a number of earthen pots are arranged in rows1 each partly filled with a mixture of vinegar1 water1 and treacle1 or some other acid fermenting liquid1 each of these pots is covered with a piece of lead made in the form of a grating 7fig4 #a71 and over all these a flooring of boards1 and then again a layer of tan1 pots covered with lead1 and boards1 two or three times repeated2 this is called a white lead bed1 and is left for several weeks2 the tan ferments and gets warm1 causing the acid vapours to rise and corrode the lead1 at the same time giving off carbonic acid4 ,at the end of about three months the leaden covers are found to have become completely changed into a white shining substance 7carbonate and oxide of lead71 this is washed from impurities and ground in a mill1 under water1 to a fine powder4 ,it is the white lead of commerce2 but what is familiarly called white lead1 is this substance ground up with linseed oil into a thick paste so as to be ready for the use of painters4 ,white lead is a very poisonous substance1 and produces the disease called painters' colic1 when taken into the system in minute quantities and for a long time1 so that all who have much to do with this dangerous substance1 as house-painters and artists1 should be extremely careful that their hands are well washed frequently1 and especially before going to meals4 ,cisterns of lead1 used for containing water1 very soon become coated inside with a thin film of sulphate of lead1 this prevents the water from acting further on the lead1 and the water from such cisterns is never found to be poisonous2 but1 if distilled water were used1 it would act rapidly on the lead1 corroding it1 and causing a deposit in the water of white lead1 which would render such water dangerous in the extreme4 ,,prussian ,,blue4 ,this beautiful blue color is made by mixing solutions of sulphate of iron 7green vitriol7 and prussiate of potash together1 when the ,prussian blue falls in the form of a precipitate1 or moist powder1 of a pale greenish color1 but which1 by exposure to the air and the addition of a little nitric acid1 becomes intensely blue2 but the ,prussian blue of commerce is never pure1 for the solution of prussiate of potash is used as it comes from the factory1 before being crystallized1 and contains carbonate of potash1 to get rid of which1 alum is added1 and the result is1 the formation of a considerable amount of alumina1 which is a white earth produced from the alum1 and which falls down in the precipitate mixed with the ,prussian blue1 which is thereby increased in bulk and but little injured in color2 when a larger quantity of this alumina is purposely produced1 the result is a blue of a rather less intense color1 called 8,antwerp blue40 ,the chemical name for pure ,prussian blue is percyanide of iron4 ,chinese blue is this substance in its purest state4 ,,prussiate ,,of ,,potash4 ,prussiate of potash is the commercial name given to what chemists call 8ferrocyanide of potassium10 it is used largely for the production of ,prussian blue1 and also in the art of electro-plating1 which1 of late1 has greatly increased the demand for its manufacture1 and many patents have been taken out for various modifications in the form of production1 the result1 however1 is the same1 and it occurs in commerce in magnificent crystals of a square form1 with bevelled edges1 and of a yellow color2 there is1 however1 another kind called the 8red prussiate10 which is much used in the process of calico printing4 ,prussiate of potash is made by heating together carbonate of potash1 scraps of iron1 and any kind of animal refuse1 as blood1 horns and hoofs1 clippings of skin or old woollen rags2 these are stirred together1 and the heat raised1 till they form a sort of paste of a black color1 which1 when cold1 is thrown into water and all the soluble parts washed out2 this fluid is filtered till quite clear1 evaporated1 and set aside that crystals may form2 these are dissolved and again crystallized4 ,the red prussiate is made by passing chlorine over the yellow prussiate in powder dissolving and crystallizing4 ,the most deadly of all poisons1 prussic or hydrocyanic acid1 is obtained from the ferrocyanide of potassium1 or prussiate of potash1 by adding diluted sulphuric acid and distilling the vapour into an ice-cold receiver4 ,this experiment should never be made by any but those well conversant with such matters4 ,,sulphate ,,of ,,iron4 ,also called 8,green ,vitriol0 and 8,green ,copperas10 is a combination of sulphuric acid and oxide of iron1 and may be made by putting iron filings or pieces of iron into a mixture of sulphuric acid and water1 and when all action has ceased evaporating the liquid1 and setting it by till crystals form--these are of a pale green color4 ,the sulphate of iron of commerce is formed by exposing the iron pyrites found in the coal districts to the air till it falls to powder2 water is then poured over this substance1 and the fluid collected and evaporated4 ,sulphate of iron is used chiefly to form the black dye so much in demand to dye cloth1 and also in making writing ink4 ,,sulphate ,,of ,,copper4 ,this substance is also known by the names1 8,blue ,vitriol0 and 8,blue ,stone40 ,it is a combination of sulphuric acid with oxide of copper1 and may be made by uniting those substances2 but what is used on a large scale for commercial purposes is obtained from the waters which flow into copper mines where 8copper pyrites0 abound2 this water is evaporated1 and the sulphate of copper crystallizes4 ,sulphate of copper has of late been in great demand for the electro-deposition of copper4 ,,chloride ,,of ,,lime4 ,chloride of lime or 8bleaching-powder0 is made for the purposes of bleaching calicoes1 linens1 c41 and also for purifying foul air1 which it does by giving out chlorine1 a gas capable of uniting with and changing the injurious properties of foul air 7which generally contains some combination of sulphur and hydrogen74 ,chloride of lime is made on the large scale by mixing hydrochloric acid with black oxide of manganese4 ,this mixture gives off chlorine4 ,this is made to pass over a layer of slaked lime1 which absorbs it greedily1 and becomes converted into the bleaching powder4 ,the hydrochloric acid used is a product resulting from the manufacture of soda1 and was formerly wasted2 it is now used in large quantities for the process above described4 8,burnett's ,disinfecting ,fluid0 is a solution of chloride of zinc4 ,it is made by dissolving scraps of zinc in hydrochloric acid2 hydrogen gas is given off1 with effervescence1 and the liquid remaining is the solution of chloride of zinc1 which acts like chloride of lime1 by giving off chlorine2 for the chloride is slowly decomposed by the air1 the oxygen of which takes the place of the chlorine1 uniting with the zinc to form oxide of zinc1 while the chlorine is set free4 ,,sulphuric ,,acid4 ,this was formerly called 8,oil of ,vitriol10 because it has an oily consistence1 and was originally distilled from green vitriol4 ,sulphuric acid is one of the most useful chemical agents known2 scarcely a process in chemical manufacture can be performed without its assistance4 ,sulphuric acid is colorless1 and very heavy1 being nearly double that of water 7the proportion is #ahdb1 while water is #a1jjj72 it is powerfully acid1 even when largely diluted with water1 and during this mixture with water gives out great heat1 a mixture of equal parts will become hotter than boiling water2 if it be mixed1 however1 with snow instead of water1 it becomes extremely cold 7below zero74 ,sulphuric acid is made by burning sulphur in a furnace1 and causing the vapours to pass into a large chamber lined with lead1 and having some water at the bottom2 into this chamber the vapours arising from nitre mixed with sulphuric acid are also admitted1 together with air and a jet of steam4 ,these arrangements require to be properly and nicely regulated1 and it was only by study of the complicated changes which take place between these gases 7sulphurous acid1 nitric oxide1 and atmospheric air71 that this arrangement has been devised and adopted1 a great part of the product having been formerly wasted in a more clumsy mode of preparation4 ,the sulphuric acid condensed in the water at the bottom of the leaden chamber is too weak for use1 and is concentrated by evaporating the water from it2 for this purpose it is placed in shallow leaden pans placed on the bars of a furnace1 and finally distilled in glass retorts1 or retorts of iron lined with platinum4 ,sulphuric acid has such a powerful attraction for water1 that an open vessel half-full of strong acid placed in a damp situation will attract enough water from the atmosphere to cause it to be quite full before long4 ,this power of attracting water has been taken advantage of to procure ice in those places where it is not to be had naturally1 as ,india1 c4 ,if a vessel of water be placed under the receiver of an air-pump1 and the receiver exhausted of air1 the vapour of the water will speedily fill it1 taking the place of the air1 and so stop any further evaporation2 but if another vessel containing some sulphuric acid be placed also in the receiver1 the acid will absorb the vapour of water as fast as it is formed1 and this rapid evaporation continuing produces such cold1 that the remaining water is shortly frozen4 ,iron and zinc dissolve rapidly in diluted sulphuric acid1 giving off abundance of hydrogen gas1 and this was the way this gas was formerly produced for the inflation of balloons1 but the common coal-gas being easily obtainable in almost any quantity in all towns1 it is now used for that purpose instead of hydrogen gas4 ,sulphuric acid 7chemically considered7 consists of #a equivalent of sulphur with #c of oxygen1 and #a of water4 ,pure sulphuric acid 7without water7 is in the form of fine crystals1 much resembling snow1 which1 on exposure to air containing the slightest quantity of moisture1 absorbs it1 and becomes converted into the ordinary sulphuric acid4 ,if this acid 7even when greatly diluted7 be spilt on cotton or linen it destroys it1 producing a hole2 this is owing to the acid converting the fibre into sugar4 ,a proposition was once made to produce sugar from this source1 but linen and cotton rags are in too great demand for paper-making to allow of its being done4 ,,leather4 ,illustration3 ,,tan-,,yard ,,and ,,pits4 ,tanning is the name given to the process for converting the skins of animals into leather1 by combining them with a substance called 8,tannin40 ,this tannin exists in many vegetable substances1 such as oak-bark1 gall-nuts1 catechu1 sumach1 c43 all of these1 and many more1 are used for tanning1 but1 on account of its cheapness1 oak-bark is the usual substance employed4 ,it is tannin which gives the quality of astringency to many vegetables1 and this very taste of astringency is produced by a partial combination of the tannin with the surface of the mouth4 ,illustration3 ,,unhairing ,,the ,,skin4 ,the skins 7called 8hides0 or 8pelts07 are first freed from all loose pieces of flesh1 fat1 or skin2 the hair is then removed by soaking them in lime and water4 ,the skins are then laid in the 8tan-pit0 between layers of crushed oak-bark until the pit is nearly full2 water is then pumped in1 and the whole is allowed to remain for several weeks or months 7according to the thickness of the skin71 during which time1 however1 the skins are changed in position by removing them from one pit to another with fresh bark in it1 so that those taken from the top of the first are placed at the bottom of the next2 and this is done from time to time1 in order that all may receive the same pressure and strength of tan-liquor4 ,very thick hides take a year to tan perfectly in this way1 and consequently many processes have been tried to quicken the operation2 but the leather made most slowly seems to wear the best1 and consequently fetches the higher prices4 ,illustration3 ,,drying ,,rooms4 ,skins which are thin1 and to be used for fancy work1 and for book-binding and glove-making1 are either tanned with 8sumach10 or with alum and salt made into a paste with flour and yolk of eggs2 this is put into a tub1 and the mixture and skins worked together with the hands till they are thoroughly united4 ,illustration3 ,,sumach ,,tan ,,tubs4 ,besides boots and shoes1 leather is used for the harness of horses1 covers for seats1 gloves1 and innumerable other purposes4 ,illustration3 ,,splitting ,,machine4 ,for some purposes the leather is required to be very thin1 and of exactly one thickness4 ,this is obtained by the process of splitting1 for which a machine is used whose exactness is such1 that one slice is taken from the inner part of the whole skin1 reducing it in thickness without cutting a hole in any part4 ,the skin is stretched tightly round a roller1 which slowly revolves against a straight knife-edge1 fixed at a certain distance from it1 according to the thickness of the skin1 and which is passed by the machine backwards and forwards1 cutting the skin a little further each time4 ,,glue ,,and ,,size4 ,glue is made from the clippings of hides or any other refuse of skins1 horn shavings1 bones1 c4 ,all these substances are piled up in a boiler having a second bottom within1 perforated with holes1 and kept from the true bottom by short feet2 this arrangement is to prevent the substances boiled from burning at the bottom of the boiler4 ,after many hours' boiling the liquid is tested1 and if it 8sets0 into a sort of jelly readily1 the liquor is drawn off into another boiler1 where it is kept warm1 that it may not set till used4 ,from this boiler it is strained through flannel into square wooden boxes1 having ridges at the bottom dividing them into squares 7to direct the workmen where to cut the glue when cold72 these boxes are set apart1 and when the contents have become cold and set into a firm jelly1 a knife is passed between the sides of the box and its contents1 and the glue turned out in a large solid square4 ,this is now cut by means of a wire with a handle at each end into squares of about eight inches each way and an inch thick2 these are now placed on nets made of cord fixed in frames one above another in a 8drying-room10 which is open to the air at the sides1 and able to be closed up in case of wet weather4 ,in this room the glue dries up1 shrinks1 and hardens1 until it is quite brittle2 the marks of the net can be seen on every square of glue4 ,size is the same as glue1 but instead of being dried it is put into small barrels4 ,two qualities of size are made1 single and double size4 ,it is much used by whitewashers1 paper-hangers1 and others1 but for any purpose requiring good size1 it may be made by soaking isinglass or gelatine in cold water till it is softened1 and then standing the vessel in boiling water till it is dissolved2 this produces a jelly nearly pure4 ,a cheaper kind of size1 almost as pure1 may be made by boiling clippings of clean parchment till they are dissolved1 and straining off the solution4 ,gelatine is the same as glue1 but made of materials that are clean and fresh4 ,isinglass is the 8sound0 or swimming-bladder of the sturgeon1 cleaned1 dried1 and cut up into fine shreds4 ,,parchment4 ,parchment is prepared from the skins of sheep1 goats1 calves1 and asses4 ,sheep-skins furnish by far the greater part of all parchment prepared1 indeed all that which is used for deeds and law purposes4 ,from whatever skin prepared1 it is first soaked in lime and water to remove the hair and greasiness1 and then stretched tightly on a frame1 and the surface rubbed smooth with pumice-stone1 after which the skin is allowed to dry4 ,parchment is used for deeds1 which require to be very durable and not easily torn1 both of which qualities it possesses much more than any kind of paper2 it is also used for book-binding1 drum-heads1 and many other purposes4 ,clippings of parchment boiled for some time1 and the liquid strained off1 forms an excellent colorless size4 ,vellum is a thick kind of parchment1 made chiefly of calf-skin4 ,,catgut4 ,what is called catgut is made from the inner or lining membrane of the intestines of sheep4 ,these are washed1 soaked1 scraped1 and otherwise prepared1 to render them even and clear2 they are then soaked in a solution of pearlash to clear them from grease1 twisted1 exposed to the vapour of sulphur1 polished by rubbing1 and afterwards stretched and dried4 ,catgut is used not only for the strings of violins and other musical instruments1 but also for what is called 8clock-makers' cord10 that is to say1 for the bow by which the drill is turned1 and for several other purposes4 ,it is very strong1 and does not easily get ragged1 as would any hempen cord4 ,,paper4 ,illustration3 ,,fig4 #a4 ,,section ,,of ,,rag ,,engine1 ,,with ,,double ,,roller4 ,illustration3 ,,fig4 #b4 ,,paper-,,making ,,machine4 ,this important article of civilisation is made from rags of various descriptions and qualities1 according to the kind of paper to be made1 the finest white paper being made of old clean linen rags1 while brown paper is made of all sorts of old rope-yarns1 sacking1 c41 and some kinds of paper have a considerable amount of straw bleached and worked up in them4 ,the rags are first sorted and cut up into small pieces2 they are then beaten on a wire screen to separate all dust1 and afterwards put into the washing-machine1 through which a stream of water runs1 and in which they are kneaded and torn by a broad wheel having iron wedges or knives fastened to its edge 7fig4 #a7 or surface1 which work as it is turned against knives of a similar description fastened to the bottom of the cistern4 ,when the rags are thoroughly washed1 and at the same time torn to a coarse pulp1 it constitutes what the workmen call 8half-stuff40 ,this is mixed with chloride of lime1 and the machine again set in motion2 this is for the purpose of bleaching the pulp2 after this has been effected1 more water is turned on1 as in the first washing1 and all the chloride of lime washed thoroughly away4 ,the pulp is now either put into another machine of the same description which cuts sharper and finer1 or else the same machine used at first is so screwed up as to cause the knives to come more closely together2 in either case the rate of turning is greatly increased1 so that the wheel turns at about #aej revolutions per minute1 and completely grinds up the pulp till it is perfectly smooth3 at this part of the process some 8indigo0 or 8smalt0 is added if the paper is to be of a blueish tint1 as in 8foolscap0 paper4 ,the 8stuff0 is now run off into a cistern ready for use4 ,paper is now nearly all made by machinery1 in pieces of a certain width1 but of an indefinite length1 and is cut up into sheets afterwards by a 8cutting machine40 ,these machines 7fig4 #b7 consist essentially of a vat1 ,a1 for the pulp1 which flows out on to a bed of wire gauze1 ,b ,b ,b1 covered with felt1 and bounded on each side by straps or deckles1 and forming a circle or endless band by being stretched over a succession of rollers1 ,c ,d ,e ,f ,g1 which1 by turning round continually1 move its upper surface onwards and between other cylinders1 which press out the superfluous moisture2 it is then carried forward till it arrives at several pairs of large hollow cylinders1 ,h ,h ,h1 heated by means of steam which is passed through them1 and which compress and at the same time thoroughly dry the paper1 which comes from them as paper perfectly formed1 and of any length that may be required4 ,it is then glazed on the surface by the rollers ,i1 and coiled on the cylinder ,l4 ,any name1 device1 or water-mark can be worked in the bed on to which the pulp flows1 and which1 being repeated at definite distances1 appears on each sheet into which the paper is afterwards cut4 ,the apparatus marked ,k is to conduct to the earth the electricity developed by the friction of the paper against the rollers4 ,beneath the bed of wire gauze1 on which the pulp is laid is a cavity from which the air is pumped1 and which causes the air to press upon the surface of the pulp1 and force out a great deal of its moisture4 ,illustration3 ,,fig4 #c4 ,,sizing ,,machine4 ,if the paper has to be sized 7which is the case in all 8hard0 papers7 it has to pass through a process1 the machinery of which is shown in fig4 #c4 ,a is a reservoir for size1 ,b a trough for the paper to dip into1 ,c the reel of paper to be sized1 ,d rollers to press out all superfluous size1 ,e a pulley to keep the paper on the stretch1 ,f ,f ,f a succession of hollow 8drums10 to prolong the passage of the paper through the air of the drying-room1 which is heated by the furnace ,g and the tubes ,i ,i4 ,h ,h are openings to admit fresh air1 and ,k openings to allow the exit of the steam from the paper as it dries4 ,l is a series of rollers to glaze it4 ,illustration3 ,,fig4 #d4 ,,cutting ,,machine4 ,the 8cutting-machine0 before referred to is represented at fig4 #d4 ,a is a wheel upon which is fixed a plate with projections and screws for fixing the position of the arm attached to the link ,b2 ,b link connecting the wheel ,a with the lever-arm ,g1 and capable of adjustment by means of the plate attached to the wheel ,a1 and the screw ,d2 ,d a screw regulating the position of the rod ,b2 ,e the drum by whose motion the web of the paper is carried forward4 ,illustration3 ,,fig4 #e4 ,,hand ,,process4 ,but the process1 as conducted by hand 7fig4 #e71 will give a much better notion of how paper is formed from the pulp4 ,a reservoir1 ,a1 is filled with pulp1 which is supplied by a wheel in the box ,b1 to a strainer ,c1 and passed to a vat ,d1 and a man1 ,e1 takes in his hands a mould consisting of a shallow frame of wood of the size the sheet of paper is to be1 having a bottom of fine wires laid side by side1 and having wires crossing at intervals to keep them firm 7the marks of these may be seen in any sheet of laid foolscap paper held up to the light72 he dips this mould edgewise into the reservoir1 and brings it up horizontally full of pulp2 this he gently shakes1 to make the pulp lie level and allow all superfluous water to drain through the wires4 ,it is then handed to another man ,h1 who has a sheet of flannel or felt spread out on a table ,f ,g1 on which the mould is inverted1 and the sheet of pulp left on the flannel1 which sucks up more of its moisture2 over this is placed another piece of flannel1 and then another sheet of pulp on it1 and so on to the number of five or six dozen ,f1 then the whole is put into a powerful press1 and screwed down till all the water is squeezed out1 when they are pretty firm1 and are lifted out and hung on lines to dry1 after which they are immersed in a cistern filled with thin size made by boiling clippings of skin in water 7see 8,glue and ,size071 and having some alum dissolved in it--they are once more pressed and dried4 ,what is called 8hot-pressed0 paper is pressed between smooth sheets of pasteboard1 having a hot iron plate placed between every three or four dozen sheets of paper2 this gives a smooth surface to the paper4 ,the names1 dates1 and other marks seen on hand-made paper are formed by wires worked into the bottom of the mould1 which1 projecting1 make the pulp thinner in those places4 ,the water-mark of ,bank-notes is made in the same way4 ,more than half-a-million sterling is paid annually for duty upon paper--so vast is the consumption6 ,,malt4 ,barley is the grain generally chosen for producing malt1 although others may be used4 ,it is first soaked in cold water till it is softened2 it is then spread out about two feet thick on the floor of the malt-house1 where it begins to germinate1 in the same manner as if sown in the earth2 this is allowed to go on so far only till the first part of the root and stem make their appearance1 in the form of a little bud and a fibre4 ,during germination the malt gives out a poisonous gas called 8carbonic acid10 and becomes warm1 in fact it would become too warm and be injured1 but it is kept stirred by means of wooden shovels from time to time1 and the temperature ascertained by means of a thermometer4 ,as the process of germination goes on1 all the starchy matter naturally contained in the grain becomes changed into sugar1 and the malt1 when made1 has a sweetish taste4 ,as soon as the germination has proceeded to a certain extent it is stopped by drying2 for this purpose the malt is put into a kiln and heated almost to scorching--if but slightly1 it is called pale malt or 8amber10 if more1 8brown malt0 or roasted malt4 ,malt1 if kept dry1 will remain a long time unchanged4 ,it is used for producing beer and vinegar1 and for 8wash10 from which all the raw spirit used in ,england is distilled4 ,whiskey is also distilled in ,scotland and ,ireland from malt4 ,malt has the property of converting the starch of barley unmalted into sugar while in contact with it4 ,for example1 if barley were ground and boiling water poured on it1 it would form a thick sort of paste1 which is because it contains starch only2 while malt treated in the same way1 sinks to the bottom1 and leaves a clear limpid 8wort10 which can be strained off1 because the starch is changed into sugar1 which is soluble4 ,now1 if equal parts of malt and ground barley be also treated in the same way1 the malt very shortly converts the starch of the barley into sugar1 and the result is the same as if all had been malt4 ,this was once a matter of great importance to the brewers1 who thereby saved the heavy duty imposed upon malt4 ,,chocolate ,,and ,,cocoa4 ,illustration3 ,,chocolate ,,crushing ,,machine4 ,chocolate and cocoa are made from the seeds or beans of the ,theobroma ,cacao4 ,the fruit of this plant somewhat resembles a cucumber1 and contains from twenty to thirty seeds2 these are dried and packed for the market4 ,they come to this country from the ,west ,indies 7,berbice and ,demerara74 ,the beans are roasted in an iron cylinder with holes to let out the vapour1 c42 when cool they are deprived of their husks1 and then crushed by means of rollers turning on a flat slab1 kept warm by stoves or steam4 ,the seeds when crushed on the warm slab become almost liquid1 owing to a kind of butter or concrete oil which they contain1 and which melts by a gentle heat4 ,when the seeds are rolled by the machine into a smooth paste1 this is either put into a mould of tin and formed into squares and various other forms1 or left rough as it is scraped from the slab 7this is called 8rock0 cocoa74 ,for chocolate it is mixed with sugar1 and either dried and powdered1 or made1 as the cocoa1 into paste4 ,on the ,continent it is flavoured with 8vanilla40 ,,steel4 ,illustration3 ,,bessemer',s ,,process4 ,steel is usually made by a process called 8cementation40 ,bars of the best ,swedish or ,russian iron1 about six feet long1 are placed in an iron box1 the bottom of which is covered with a layer of charcoal powder2 over the first row of iron bars some more charcoal is put1 and then another row of iron bars1 and so on till the box is full1 when it is carefully closed and kept at a white heat for four or five days4 ,when cold1 the bars are found to be converted into steel1 and1 being rough and blistered on the surface1 are called 8blistered steel20 this is broken up1 and the bars laid side by side and made hot in a forge1 where they are welded together by the blows of a heavy hammer1 and drawn or rolled out by machinery into bars of 8fine steel40 ,steel differs from iron in the closeness of its grain1 in being very much 8tougher10 and in having that very useful and peculiar property called 8temper10 which is the power of hardening when suddenly cooled while red-hot4 ,if a bar of steel as soft as iron be made of a bright red heat1 and then suddenly plunged into cold water1 it will be found to have become harder than any other metal 7so hard1 indeed1 that it will scratch glass71 and is as brittle and readily broken as flint or glass4 ,if now a gentle heat be applied to it1 this extreme hardness of temper gives way4 ,for instance1 if a piece of bright hard steel is held for a moment in the hollow of a clear fire1 a pale straw color appears on its surface1 it is now still very hard 7but not so hard as before71 and is fit for razors1 surgeons' instruments1 c2 but if held in the fire a moment or two longer1 it becomes of a bright golden yellow1 and is fit for penknives1 and other cutting instruments2 held longer still1 it becomes bright blue1 and is fit for watch-springs1 swords1 and other purposes requiring great elasticity but no great hardness2 if the heat be carried still further a brown tinge is seen1 and it is now rather soft1 but greatly harder than iron1 and is still elastic2 saws1 coach-springs1 and many other articles are made from steel at this temper4 ,if the heat be carried on to redness1 the steel would be quite soft when it had slowly cooled1 but if suddenly cooled 7as by being plunged into water7 the original hard temper comes back again4 ,steel1 like iron1 may be cast1 and cast-steel is one of its most useful forms1 and much resembles 8fine steel40 ,the mode of preparing cast-steel is to melt the 8blistered steel0 in a crucible1 or earthen pot1 and then run it into a mould3 this forms an 8ingot0 of steel1 which may be afterwards rolled or welded as the case may require4 ,steel may be drawn into very fine wire1 or wrought into the most minute articles1 as the springs and other parts of watches4 ,it bears a very fine and bright polish1 and does not rust or tarnish so easily as iron4 ,it has lately been proposed to make heavy cannon of cast-steel1 which is much tougher than either cast-iron or gun-metal4 ,illustration3 7 ,,fig4 #a4 and ,,fig4 #b47 ,,perpendicular ,,sections ,,of ,,converting ,,vessel4 ,illustration3 ,,fig4 #c4 ,,outside ,,view ,,of ,,converting ,,vessel4 ,a process has lately been invented by ,bessemer to supersede the long and laborious process of 8puddling40 ,it consists essentially of transferring the melted iron into a vessel in which there are tubes inserted at the lower part1 and through which air is forced at a great pressure1 which bubbles up in streams through the melted metal1 and1 as it does so1 unites with the carbon and sulphur of the iron1 converting them into carbonic and sulphurous acids1 and at the same time producing an increased heat1 which is quite necessary to the success of the process1 for as the iron becomes purer it also becomes more difficultly fusible1 and would set into a solid mass1 but that this greatly increased temperature keeps it fluid4 ,this rising of temperature is similar to what takes place upon blowing a common fire with bellows2 for the more air that is admitted to carbon raised to a very high temperature1 the more rapidly does it combine with its oxygen1 or1 in other words1 the more rapidly does it burn4 ,so that1 in this process of ,bessemer's contriving1 the carbon of the iron acts as fuel to keep up the heat necessary to maintain its fusion1 and at the same time1 by being converted into carbonic acid1 escapes in bubbles 7like the bubbles which escape from soda-water71 and this rapid production of gas in every part of the fused iron also assists in bringing about a thorough stirring-up and mixing together of all its parts4 ,reference to the accompanying diagrams will illustrate the working of the process4 ,in figs4 #a and #b1 ,a ,b are lower chambers1 ,c is the melted iron1 ,d is an upper chamber for melting scrap-iron1 c41 ,e in fig4 #a and ,d in fig4 #b are openings for the escape of gas and flame1 ,f ,f is an air-passage running all round and communicating by ,g with the tuyere-holes shown at ,e in fig4 #d1 ,h is the fire-brick lining to the furnace1 and ,i the tapping-hole through which the fluid iron is discharged4 ,in fig4 #c1 ,i is the tapping-hole1 ,k the main air-tube leading from the blast-engine1 ,l ,l perpendicular tubes 7marked ,g in figs4 #a and #b7 leading from circular air-passage to tuyere-holes1 ,m is an opening for the insertion of iron into the upper chamber1 opposite to opening ,d in fig4 #b1 and ,n the tap for regulating the blast2 ,o indicates the outer casing of wrought iron4 ,when the process is carried only to a certain point1 the result is a sort of semi-steel1 which the inventor of the process expects will be a very useful article of commerce4 ,illustration3 ,,fig4 #d4 ,,horizontal ,,section ,,or ,,plan ,,of ,,converting ,,vessel4 ,during the bubbling up of the whole mass of iron and the extreme elevation of temperature caused by the union of the carbon of the impure iron with the oxygen of the air1 the oxide of iron as fast as it forms fuses into a sort of glass1 and this unites with the earthy matters of the impure iron and floats on the upper part as a flux1 thus ridding the cast-iron of all its impurities1 with no other fuel than that contained in the iron itself and the air4 ,the accompanying illustration represents a horizontal section or plan of the converting vessel2 ,a the central chamber1 ,b a lining of fire-bricks1 ,c the main air-tube1 ,d the tapping-hole1 ,e the tuyere-holes through which the air is forced into the melted iron to be purified1 ,f is the outside casing of wrought-iron4 ,,tin-,,plate1 ,,and ,,galvanised ,,iron4 ,what is usually called tin is1 in fact1 sheet-iron coated with tin1 and of this tin-plate1 kettles1 saucepans1 c41 are made4 ,the art of coating iron plates with tin has been practised in ,england hardly more than one hundred years4 ,the very best soft iron is used for the purpose of being tinned4 ,it is rolled out into thin plates1 which are cut by shears into squares of usually thirteen inches long and ten broad1 these plates are dipped into weak acid to clean their surfaces1 then rubbed with sand1 and finally washed2 they are next dipped into melted tallow1 which preserves their surfaces bright till they can be used4 ,they are then immersed in melted tin1 which has its surface covered with melted tallow1 to keep it from being converted into oxide4 ,when the plates have remained for a short time in the tin1 they are removed1 and the superfluous tin is wiped from the lower edge with a brush made of hemp1 and then cleaned from the grease with dry bran4 ,the objects gained by coating iron with tin are1 increased beauty of appearance 7for when tinned ware is kept bright1 it has almost the color of silver71 and a protection to keep the surface from rusting1 and consequently being corroded into holes4 ,copper and brass vessels are tinned inside1 to prevent the formation of that poisonous substance called verdigris4 ,the mode of tinning them is as follows3--,they are cleaned inside by means of vitriol1 and then made hot1 fine grain-tin and a little rosin being put into them1 and turned about and brushed over the surface with a ball of tow3 by this means1 the tin is equally spread over the inner surface of the vessel4 ,tin-tacks1 buckles1 and other small articles1 receive a coating of tin by being put into an earthen pot together with some grain-tin and a substance called 8sal ammoniac10 and the pot being heated over a fire sufficiently to melt the tin1 is then shaken up till the articles inside have received a coating of tin4 ,iron plates have lately been coated with melted zinc instead of tin1 and the surface thus covered enables them to be used for various purposes and in situations where they are exposed to the action of the weather1 as on housetops1 c4 ,the plates1 thus treated1 are called 8galvanised iron10 and they are generally used in a corrugated form4 ,they withstand the action of the weather very much better than simple iron plates would1 for the latter would be very soon eaten into holes from rusting4 ,,glass4 ,this most useful and elegant material--now an article of almost universal application1 in various forms--is made on a very large scale by fusing together sea-sand and alkali 7either potash1 soda1 or lime71 and1 in the case of 8crystal10 or 8flint-glass10 oxide of lead4 ,the following is about the composition of the chief kinds of glass in use3-- ,,flint ,,glass4 ,,parts4 ,,plate ,,glass4 ,,parts4 ,pure white sea-sand #eb ,pure white sand #ee ,potash #ad ,soda #ce ,oxide of lead #cd ,nitre #h ------ ,lime #b #ajj ----- #ajj ,,crown ,,glass4 ,,parts4 ,,green ,,bottle ,,glass4 ,,parts4 ,fine white sand #fc ,sea-sand #hj ,chalk #g ,salt #aj ,soda #cj ,lime #aj ---- ---- #ajj #ajj ,flint-glass or 8crystal0 is very heavy1 moderately soft 7being easily cut with a file71 and very bright and white4 ,it is used for all table-glass1 as decanters1 wine-glasses1 c41 and for the drops or lustres of chandeliers4 ,plate-glass is that kind of glass now in such general use for shop-windows1 looking-glasses1 c4 ,it is cast on flat iron tables1 and rolled out to the sizes required1 then cut and polished by machinery4 ,in the rough state it is called 8rough plate10 and is the substance used in the ,crystal ,palace1 and has of late become almost a substitute for ground glass1 which is simply ordinary glass ground or roughened on the surface by means of sand1 so that it will admit light and yet not allow objects to be seen through it4 ,crown-glass is the ordinary 8window-glass40 ,it is made in great circular pieces 7see 8,glass-blowing071 and cut up into the sizes required4 ,crown or window-glass made some years back1 had a disagreeable tinge of green1 which has been removed in modern glass by the addition of a minute quantity of oxide of manganese4 ,illustration3 ,,fig4 #a4 7 ,,overhead ,,diagram ,,of ,,furnace47 ,the ingredients to be made into glass 7of whatever kind it may be7 are thoroughly mixed together and thrown a little at a time into large crucibles or melting-pots placed in a circle 7,a ,a1 fig4 #a7 in a furnace resting on buttresses 7,b ,b1 fig4 #a71 and heated to whiteness by means of a fire in the centre1 ,c1 blown by a blowing machine1 the tube of which is seen at ,d4 ,this furnace is shown in perspective in fig4 #b4 ,the ingredients melt and sink down into a clear fluid1 throwing up a scum1 which is removed from time to time4 ,this clear glass in the fused state is now kept at a white heat till all air-bubbles have disappeared2 the heat is then lowered to a bright redness1 when the glass assumes a consistence and ductility suitable to the purposes of the glass blower4 ,illustration3 ,,fig4 #b4 7 ,,exterior ,,view ,,of ,,furnace47 ,artificial gems are all but varieties of glass4 ,what is called 8paste10 8,french diamonds10 c41 are glasses of peculiar brilliancy1 well cut and polished4 ,garnets1 emeralds1 and other precious stones are imitated by coloring the 8paste0 with various substances1 chiefly metallic oxides1 as oxide of cobalt1 which produces a blue color1 oxide of copper a red1 and oxide of chromium a green color1 c4 ,glass is used for a variety of purposes besides the one great purpose of admitting light to houses while air and damp are excluded4 ,it furnishes an immense variety of beautiful and useful articles in the form of drinking-vessels1 vases1 chandeliers1 c41 and to the chemist and manufacturer generally1 it is invaluable1 for vessels of glass thoroughly resist the action of all acids 7with the exception of the hydrofluoric7 and nearly every other substance4 ,it stands a considerable heat1 and if made equal in substance and rather thin1 will not easily crack by sudden alterations of temperature4 ,without glass1 microscopes1 telescopes1 cameras1 barometers and thermometers--upon which some of our best and most useful knowledge and some very beautiful results of chemical action depend--could hardly have been constructed4 ,,soda-,,water4 ,soda-water was formerly prepared by the ordinary chemist1 but since it has become so general a beverage has been made a separate branch of chemical manufacture4 ,soda-water consists of a very weak solution of carbonate of soda1 holding a large quantity of carbonic acid in solution1 for water has the property of absorbing a certain quantity of carbonic acid1 and this quantity is increased in proportion to the pressure exerted on the water4 ,this pressure is secured in the first place by machinery1 and afterwards maintained by the bottle being closely corked and the cork fastened in by means of wire4 ,illustration3 ,,fig4 #a4 ,,soda-,,water ,,apparatus4 ,in fig4 #a there is an illustration of the machinery used4 ,it consists of a small vessel holding sulphuric acid1 attached to another vessel containing chalk and water kept constantly stirred by a small windlass passing through a hole in the top1 and working air-tight4 ,when some of the sulphuric acid is allowed to run into the vessel holding the chalk an effervescence takes place1 and a rapid extrication of carbonic acid2 this is conducted by a tube to a gas-holder as a store4 ,a tube leads from this gas-holder into a sort of air-pump1 and a man1 by turning a windlass1 not only works this and thereby forces a certain quantity of gas into another vessel of copper 7plated with silver inside71 but turns this vessel itself rapidly round4 ,in this vessel the solution of carbonate of soda is placed1 and is agitated under pressure with the carbonic acid thus forced into it1 and which it rapidly absorbs4 ,from this vessel it is drawn off into bottles1 which are adroitly corked before much of the carbonic acid can escape1 and then wired down1 a fresh supply of solution of soda and carbonic acid being constantly introduced4 ,potash-water and ,carrara water are made in the same way1 using potash in the former1 and chalk in the latter1 instead of soda4 ,illustration3 ,,fig4 #b4 7 ,,soda-,,water ,,bottle47 ,the form of a soda-water bottle is shown in fig4 #b2 it is made of very thick glass1 that it may resist the outward pressure of the carbonic acid1 and so formed that it cannot stand on its bottom1 and when laid on its side the bubble of air shall rise up to the middle of the bottle and not to the cork1 or else it would escape through the cork before long1 however nicely it may be fitted4 ,illustration3 ,,fig4 #c4 7 ,,dispensing ,,bottle47 ,fig4 #c is a convenient vessel for holding about a quart of soda-water or any other effervescing drink1 all of which is not at once required4 ,a tube passes from the top to nearly the bottom of the vessel1 and when this is filled with aerated water1 the expansive power of the carbonic acid forces the water up this tube and out of the spout when the handle is depressed and the tap opened1 and when sufficient is obtained1 the tap can be immediately closed4 ,a very convenient apparatus called a 8,gasogene0 has lately been constructed4 ,it consists of a double vessel1 into the upper part of which a solution of any kind--wine and water1 or even plain water--is put1 to be saturated with carbonic acid or 8aerated10 and into the lower one some carbonate of soda and tartaric acid4 ,a tube leads from this lower to the top of the upper vessel1 which screws on and off4 ,by shaking the apparatus when thus charged and screwed together1 some of the liquid descends through the tube into the lower vessel and moistens the soda and acid1 which therefore act on each other1 and cause carbonic acid to be disengaged2 this1 rising up through the tube 7which is perforated with small holes at the upper part71 disperses itself through the liquid in small bubbles1 and causes sufficient pressure to enable the liquid to absorb it1 which therefore effervesces when drawn off by the tap and this pressure removed4 ,,coal-,,tar ,,naptha4 ,this is distilled from the coal-tar produced at the gas-house1 the residuum being pitch1 and it has a very offensive smell4 ,it is in demand as a solvent for ,india-rubber1 and also for use in lamps so constructed as to require no wick1 for naptha is very volatile1 and the vapour is burnt as it rises4 ,,wood ,,naptha1 ,,or ,,pyroxylic ,,spirit4 ,this is often called wood spirit1 and is procured from the tar resulting from the distillation of wood for wood vinegar or pyroligneous acid4 ,it is colorless1 without the disagreeable odour of coal-tar naptha1 and very inflammable1 burning without smoke1 very much in the manner of spirits of wine4 ,it is used in varnish-making1 and also for burning in lamps where heat and not light is required4 ,,products ,,of ,,skilled ,,labour4 ,,pottery4 ,illustration3 7 ,,pottery ,,workers47 ,illustration3 ,,stampers4 ,illustration3 ,,flint ,,mill4 ,the art of making vessels of earth is one of the oldest of all arts2 the 8potter's wheel0 is frequently named in ,scripture1 and pottery is found in all the remains of ancient nations4 ,earthenware is made from a mixture of clay and powdered flints2 the clay is freed from all its coarser parts by being stirred with water and drawn off after the gross matters have settled2 the fluid is then allowed at leisure to let fall the pure clay which was mixed with it1 and is then fit for use4 ,the flints are made red-hot1 and in that state thrown into cold water1 which makes them so brittle that they can be easily broken up by the 8stampers10 which are perpendicular pieces of iron made to rise and fall with great force2 the flints are then ground in a mill to a powder1 which is treated in the same way that the clay was4 ,when these two earths are mixed in proper proportions1 and beaten together while moist1 they form a substance of the consistence of putty1 a lump of which is thrown into the centre of a piece of board turned by means of a wheel and treadle2 while turning round1 it is moulded by the hands into a rough outline of the vessel required1 and afterwards put aside to dry till it becomes of such hardness1 that it can be easily turned in a common lathe1 and formed into the cup1 jug or whatever else it may be intended for4 ,this is then baked in a 8kiln0 or oven so contrived that it shall make it red-hot1 and keep it so for about two days4 ,if it has to be ornamented with a design-such1 for instance1 as the 8willow pattern0--a number of prints on tissue paper of the subject required are kept ready1 and one of these is stuck on to the vessel with the printed side next to the clay1 and rubbed smoothly on to it2 after a little time the paper is washed off with water1 and the pattern is left on the vessel4 ,the next process is that of glazing2 this is done by dipping the vessel into a mixture generally made of ground flints and oxide of lead made into a thin fluid with water2 when the glazing is dry the vessel is once more put into the kiln1 and made red-hot1 when the glazing-mixture on the surface melts into a smooth glass4 ,different colours are given to the pattern by mixing certain metallic substances with the ink used in printing4 ,the handles1 spouts1 and other projecting parts are fixed on after turning1 and before the ware is put into the kiln4 ,many kinds of pottery are not turned at all1 but made in a mould by being squeezed forcibly into it2 this is the case when the article to be produced is octagonal1 or possessed of any form not round1 and therefore not to be produced by turning1 and when the surface has a pattern or figures standing out in relief4 ,some of these are made by filling shallow moulds with the clay1 and1 while moist1 affixing them to the surface1 but the handles of common ware are made by forcing some of the clay through a hole of the required form1 so that it comes out in long strips or ribands1 which are cut up into lengths1 bent into the proper form1 and stuck on to the ware1 some softer clay being smeared round the joint--the whole1 when baked in the kiln1 becoming hard and strong4 ,earthenware is often made to possess some color throughout1 as drab1 yellow1 brown1 or black4 ,these tints are produced by admixture of different kinds of clay and oxides in various proportions1 oxide of iron generally giving a red or chocolate color1 and oxide of manganese a drab1 brown1 or black color1 according to the proportion used4 ,figures1 busts1 and many other articles1 both for ornament and utility1 are made of porcelain by casting1 and are produced by filling hollow casts of plaster of ,paris with the materials for porcelain1 mixed with water to the consistence of cream--this is called 8slip10--and when the hollow cast is filled the porous plaster absorbs most of the moisture from the portion of liquid 8slip0 next to it1 so that1 after a time1 what remains fluid being poured out1 there is found a coating or lining of porcelain mixture of considerable thickness adhering to the interior of the mould too solid to be poured out2 the whole is then set in a warm place to dry1 and as the porcelain shrinks as it dries1 it separates itself from the mould--which1 being made of several pieces fastened together1 is taken apart without injuring the cast2 after it has thoroughly dried it is baked in a kiln or furnace4 ,this is called 8,biscuit porcelain40 ,,bricks ,,and ,,tiles4 ,illustration3 ,,pug ,,mill4 ,illustration3 ,,stool1 ,,or ,,working ,,shed4 ,illustration3 ,,barrow ,,for ,,wet ,,bricks4 ,illustration3 ,,barrow ,,for ,,dry ,,bricks4 ,bricks are made of clay mixed with sand or ashes4 ,the brick-field is first covered with either of these to the depth of an inch or two1 and is well dug in and turned about during several weeks2 when the bricks are to be made1 the mixture is put into a 8pug mill20 this is a large tub having an upright iron bar passing up from the bottom1 and having several broad iron blades fixed to its sides at the part which is in the tub2 at the top there is a cross-bar of wood1 to which a horse is harnessed2 the horse1 when driven round in a circle1 turns the upright iron bar and consequently the iron blades4 ,into this tub the clay and ashes are now put1 a little at a time1 and as the horse goes round they are thoroughly mixed together2 a man takes pieces of this clay of the proper size1 and hands them to another who stands before a table in the shed1 and has a mould before him2 this consists of a piece of wood with sides of the size of the brick1 which is always ten inches long1 five broad1 and three thick1 before burning4 ,the sides of this mould can be turned up and down2 they are now put up1 and the piece of clay forced into the mould and scraped off even at the top1 the sides are put down1 and the brick placed carefully on a barrow1 which when filled is wheeled off by another man1 and its contents arranged on the ground in long lines having a small space between each brick1 that they may not stick together and the air may dry them4 ,long rows of these bricks are formed one on the top of the other1 for four or five deep1 and are changed in their position from time to time till they are quite dry and hard2 they are now ready to be burnt4 ,this is done made by placing the bricks in long rows1 with narrow spaces between each row which are filled with straw or twigs of wood and cinders 7these cinders are got from the ashes when they are sifted before mixing with the clay72 the spaces being filled they are covered with other bricks1 and then the straw1 c41 is lighted4 ,layer after layer of bricks are next built up around the fire1 so that the heat shall be well kept in1 and in this way the bricks are gradually baked till they are quite hard and fit for use4 ,illustration3 ,,burning ,,bricks4 ,tiles are the same as bricks1 but of a different form1 being flat1 and having two holes in them to receive nails4 ,these are used to form the roofs of houses1 and are nailed on to the rafters1 each layer overlapping the one below it1 so that the rain falling on the sloping roof shall run from the top to the bottom without coming through4 ,bricks have lately been made with perforations through them1 which is done by having a mould with a number of iron rods projecting from its bottom1 so that when the clay is forced on them they pass right through it1 and leave holes4 ,the objects gained by this are two2 in the first place1 the bricks are much lighter1 a great advantage in building1 and in the second place they do not get so much out of form in burning1 as there is no great substance between the holes1 and therefore the shrinking takes place more evenly4 ,most of these bricks are of a light straw color1 and are used for facing4 ,they are mixed with a quantity of chalk1 which is worked up with the clay1 and are not baked at such a heat as would burn it into lime4 ,illustration3 ,,mixing ,,chalk4 ,,tobacco-,,pipes4 ,tobacco-pipes are made of a fine white clay1 found chiefly in the island of ,purbeck1 and called1 from its use1 pipe-clay4 ,dr4 ,ure gives the following account of the manufacture of tobacco-pipes3--8,a child fashions a ball of clay from the heap1 rolls it out into a slender cylinder upon a plank1 with the palms of his hands1 in order to form the stem of the pipe4 ,he sticks a lump at the end of the cylinder1 for forming the bowl2 which1 having done1 he lays the piece aside for a day or two to get more consistence4 ,in proportion as he makes these rough figures1 he arranges them by dozens on a board1 and hands them to the pipe-maker4 ,the pipe is finished by means of a folding brass or iron mould1 channelled inside of the shape of the stem and the bowl1 and capable of being opened at the two ends4 ,it is formed of two pieces1 each hollowed out like a half pipe cut as it were lengthwise1 and these two jaws when brought together constitute the exact space for making one pipe2 there are small pins in one side of the mould1 corresponding to holes in the other1 which serve as guides for applying the two together with precision4 ,the workman takes a long iron wire1 with its end oiled1 and pushes it through the soft clay in the direction of the stem1 to form the bore1 and he directs the wire by feeling with his left hand the progress of the point4 ,he lays the pipe in the groove of one of the jaws of the mould1 with the wire sticking in it1 applies the other jaw1 brings them smartly together1 and unites them by a clamp or vice1 which produces the external form2 a lever is now brought down1 which presses an oiled stopper into the bowl of the pipe while it is in the mould1 forcing it sufficiently down to form the cavity1 the wire in the meanwhile being thrust backwards and forwards1 so as to pierce the tube completely through2 the wire must become visible at the bottom of the bowl1 otherwise the pipe will be imperfect4 ,the wire is now withdrawn1 the jaws of the mould opened1 the pipe taken out1 and the redundant clay removed with a knife2 after drying for a day or two1 the pipes are scraped1 polished with a piece of hard wood1 and1 the stems being bent into the desired form1 they are carried to the baking kiln1 which is capable of firing fifty gross in from eight to twelve hours4 ,a workman and a child can easily make five gross of pipes in a day40 ,illustration3 ,,furnace4 ,the pipes known as 8meerschaum0 are cut and shaped out of a natural earth or mineral1 found chiefly in the island of ,samos2 it is not a clay1 but consists of silica1 magnesia1 and lime1 and is therefore a kind of magnesian limestone4 ,it is nearly white1 very light and porous1 is easily cut with a knife1 and bears a beautiful polish when saturated with the oil of the tobacco1 which at the same time gives to the pipes a rich dark-brown color4 ,the meerschaum pipes sold in ,london are saturated with wax or grease1 to cause them to color more easily1 and many are not meerschaum at all1 but are made of the dust produced in the cutting and boring of the real meerschaum pipes1 mixed up with size2 these fictitious pipes are heavier and less porous than the true meerschaum pipes1 and neither color so readily nor bear so beautiful a polish2 they are1 moreover1 much more easily broken4 ,,gold-,,leaf4 ,for the purpose of gilding very thin leaves of gold are required1 so thin1 that although gold is expensive1 yet gilded articles 7as picture-frames7 are very far from being so4 ,to produce this gold-leaf is the business of the gold-beater4 ,he first obtains the gold in a state of purity from the refiner1 in the form of small grains1 which1 mixed with a small quantity of borax and alloy1 are put into an earthen pot called a crucible 7coated beforehand with clay to keep it from cracking71 and then placed in a furnace which is raised to a white heat4 ,the gold1 when melted1 is poured into an iron mould made warm and greased in the inside2 this when cold forms an 8ingot10 which weighs two ounces1 and is three-quarters of an inch square and not quite half-an-inch thick4 ,this ingot is now sent to the 8flattening mills10 where it is passed between sets of steel rollers until it is rolled out into a sort of riband an inch wide and about twelve feet long 7at this degree of thinness a square inch will weigh six-and-a-half grains74 ,it is now cut into #aej pieces1 each an inch square1 which are packed between pieces of vellum1 four inches each way1 and surrounded by a sort of bag of the same material1 the whole being then subjected to the blows of a heavy iron hammer 7weighing about fourteen pounds7 upon a block of solid stone1 till the plates of gold are beaten out nearly as large as the vellum1 when they are taken out and each cut into four pieces4 ,these quarters are treated as before1 using gold-beater's 8skin0 instead of vellum 7this skin is prepared from the intestines of the ox1 and a set of these1 consisting of several hundreds1 is called a 8mould071 and the gold again extended under the hammer to the size of the mould4 ,the process is repeated in the same manner a third time1 after which the leaves of gold are taken out1 cut square on a cushion of leather1 lifted carefully by means of a sort of tongs made of wood1 and placed in the book4 ,they are now between #fjj and #gjj times thinner than before the beating commenced1 and it would take about #bhj1jjj of these leaves to make the thickness of an inch4 ,the leaves are from three to three-and-a-half inches square1 and are packed in books of paper having the surface of the leaves rubbed with red chalk1 to prevent them from adhering to the gold2 each book contains twenty-five leaves of gold4 ,the different colors of gold-leaf1 such as 8pale gold10 8deep gold10 or 8red gold10 are produced by a small alloy of copper or silver1 the former giving a deeper and the latter a paler tinge to the pure gold4 ,a certain amount of alloy is always mixed with the pure metal1 otherwise it would adhere to the mould1 and would not work so well4 ,,shot4 ,illustration3 ,,shot ,,tower4 ,illustration3 ,,sieve ,,for ,,making ,,shot4 ,illustration3 ,,section ,,of ,,shot-,,tower4 ,shot are made either of iron or lead4 ,all shot for great guns or cannon are made of iron1 but for small-arms leaden balls are used1 which are cast to fit the bore of the weapon4 ,for sporting purposes small shot are made1 of different sizes2 they consist of globules of lead with a small proportion of arsenic mixed with it--the object of mixing arsenic is to make the shot divide better1 as it has been found by experience that lead alone does not divide so well--this mixture1 while in a fluid state1 is poured through a colander or sieve made of iron and having the bottom perforated with small holes1 to suit the size of the shot to be made4 ,these colanders are placed at the top of a high building like a tower1 and the melted metal runs through the perforations in fine streams and separates into single drops as it falls4 ,at the bottom of the building the shots are received in vessels of water1 to cool them4 ,in these vessels all the little globules are not exactly of the same size1 although the holes in the colanders regulate this to a certain extent1 moreover they are not all round2 they have1 therefore1 to be sorted1 which is done by placing the shot by handfuls upon a board slightly tilted1 so that the round ones roll to the bottom and are received in a box1 those that are crooked1 c41 lag behind on the board1 and are put aside to be re-melted4 ,the shot in the box have next to be sorted as to size2 this is done by means of two sieves2 the holes of one sieve are a little larger than the size of the shot required1 and this retains therefore all that are too large1 the next has holes a little less than the shot1 and this retains the right size and lets all the shot that are too small pass through2 by these simple means the shot are separated into many sizes1 which are numbered4 ,the shot have now to be finished1 which is done by turning them1 mixed with a little black-lead1 in a sort of barrel1 which gives them a beautiful black shining surface1 and rubs off any roughness4 ,,files4 ,illustration3 ,,file ,,cutting4 ,files are among the most useful of tools for those who work in metals1 and in many other substances1 as ivory1 or hard woods4 ,a file consists of a bar of steel of various shapes1 such as flat1 square1 three-cornered1 round1 and half-round2 on the surface of this bar of steel small furrows are formed1 with rough projections between them1 and these are again1 in most kinds of files1 crossed with others4 ,the mode of making a file is as follows3--,a bar of wrought or cast steel is cut off of the requisite length and of the proper figure1 and forged on an anvil to the required shape--that is to say1 rather tapering at the top and brought to a point 7called the 8tang07 at the bottom1 so that it may be driven into a wooden handle4 ,the file has now to be cut4 ,to do this requires great manual dexterity4 ,a man sits before a bench1 and passes a strap over each end of the file so as to steady it1 and these are kept down with the feet4 ,a small chisel of hard steel is held in the left hand between the thumb and finger and struck with a short-handled heavy hammer1 the effect is to cut a notch1 with an elevation at each side called a 8burr20 the small chisel is slipped up to this 8burr10 and struck again1 and so on till the whole file is cut1 and this with such rapidity that the eye can scarcely follow it4 ,when the file is thus notched from end to end1 it has to be hardened1 which is done by making it red-hot and suddenly plunging it into cold water1 which makes it so hard that it will scratch glass and cut away any other metal4 ,illustration3 ,,file4 ,illustration3 ,,rasp4 ,for softer substances1 such as wood1 a kind of file is often used called a 8rasp10 which1 instead of having furrows cut on it1 is struck into little dints by means of a three-cornered piece of hard steel1 which1 as it enters the file1 throws up a projection also4 ,for filing bone and ivory1 a kind of file is used with very large notches1 not crossed by others1 the edge of each of which acts like a plane-iron or chisel1 and takes off shavings from the bone4 ,,type4 ,illustration3 ,,type ,,casting4 ,the casting of types for printing is for the most part done by hand1 and singly1 and it is one of those arts in which extreme dexterity 7only to be acquired by incessant practice7 enables the founder to accomplish an amount of labour which would seem to any one not witnessing the process impossible4 ,to cast each piece of type it is necessary to dip a little ladle into a pot of melted metal1 to fill the mould1 give it a sudden jerk with the left hand so as to make the melted metal go well into the little mould1 open the mould and take the type out1 shut up the mould and fasten it1 and yet a skilful workman can perform these operations five hundred times in an hour--that is to say1 rather more than eight times in a minute--producing a type each time2 this has afterwards to be finished off by others4 ,the metal of which type is made consists of lead and antimony--the antimony hardens it and makes it take a sharper impression4 ,the letters are first cut in steel1 and from these 8dies0 the moulds are made in brass1 by stamping1 and in these the types are cast4 ,stereotype consists of plates of metal taken1 by casting1 from a forme of type set up for the purpose2 an impression in plaster of ,paris is first taken1 and from this the metal impression is cast1 so that the original forme of type may be 8distributed0 or taken to pieces1 and again used1 while the stereotyped impression can be preserved for any future printing4 ,,lucifer-,,matches4 ,illustration3 ,,filling ,,the ,,boxes4 ,these convenient matches1 which have completely superseded the old apparatus of flint1 steel1 and tinder-box1 may be looked upon as one of the improvements derived from chemistry1 for phosphorus--the necessary ingredient--till lately sold at half-a-crown an ounce2 such a price would1 of course1 prevent its being used for so general a purpose as match-making4 ,but when chemistry devised means of preparing it on a large scale1 and at a low price1 then its application was soon perceived4 ,illustration3 ,,cutting ,,the ,,matches4 ,illustration3 ,,frame4 ,some years ago a kind of match was used1 made of chlorate of potash and sulphuret of antimony1 and ignited by drawing through a folded piece of glass-paper4 ,another sort was also for a time in use called 8,prometheans10 but far too expensive for general use4 ,they consisted of strips of paper rolled up1 with a little glass cylinder full of sulphuric acid sealed up in the end of each1 surrounded by chlorate of potash in powder2 the end of the match had to be crushed by a small pair of nippers1 and the glass being broken1 the sulphuric acid came in contact with the chlorate of potash1 causing it to take fire4 ,illustration3 ,,filling ,,the ,,frame4 ,illustration3 ,,dipping ,,the ,,matches4 ,for making lucifer-matches the wood is sometimes split by hand1 and sometimes by machinery4 ,for those the wood of which is rounded1 a peculiar apparatus is used2 it consists of a plate having small steel cylinders let into it1 so that their cutting edges are raised above the plate1 and the wood is struck upon this1 and not only divided1 but each piece forced through the cylinders and so rounded4 ,when cut1 the wood is dipped in bundles into melted sulphur1 and afterwards into a composition variously made1 but usually consisting of phosphorus ground up with gum arabic and water1 colored either with red-lead or ,prussian blue1 and in some cases chlorate of potash is added4 ,this composition is spread out on a board to about the tenth of an inch in thickness1 and the matches which have been dipped in sulphur are packed into a frame to the number of about #cjjj1 and dipped by pressing them on the board spread with the composition1 so that a little is attached to the ends of each match4 ,this is a most unwholesome and dangerous employment1 and water is always at hand1 in case of fire1 which is chiefly to be feared in the process of separating them and filling the boxes when the composition has dried4 ,,candles4 ,illustration3 ,,candle ,,manufactory4 ,illustration3 ,,cutting ,,the ,,wicks4 ,candles are made of either wax1 spermaceti1 stearine1 or tallow1 or some compound or modification of these2 but of whatever they may be made1 they are formed either by dipping or casting1 and hence the names 8dips0 and 8moulds40 ,illustration3 ,,horse',s ,,head4 ,illustration3 ,,cooling ,,frame4 ,when dips are to be made1 a quantity of wicks of spun cotton are prepared by a machine1 and doubled so as to form a loop at the top1 through which a stick is passed4 ,a number of wicks are arranged in a line on each stick1 and several sticks placed side by side on a frame1 which is attached to one end of a balance beam 7called by the workmen the 8,horse's ,head071 with weights at the other end1 according to the weight of the candles to be made4 ,the frame1 with the wicks upon it1 is suspended over a cistern of melted tallow 7kept warm by a small fire or flue71 into which it is lowered1 so that the wicks dip into the tallow2 this is repeated two or three times1 till a coating of tallow is formed on the wicks1 which are then placed aside to cool while others are served in the same way1 and so on1 over and over again1 till each frame weighs enough to exactly counterpoise the weight at the other end of the beam4 ,illustration3 ,,candle-,,moulds4 ,mould candles are made by pouring melted tallow into a wooden trough in the bottom of which pewter moulds1 of the size of the candles required1 are fixed in such a way that they open into the trough by the ends which correspond to the bottoms of the candles to be cast in them4 ,the other end of the mould is brought to a point1 with a small hole in it1 through which the wick is passed and fastened to a stick running along the moulds2 and as the moulds are placed in two lines1 two sticks are sufficient for the trough4 ,melted tallow or spermaceti is poured into the trough1 and when cold the superfluous quantity removed1 and the candles drawn out of the moulds4 ,wax candles are made by pouring melted wax down the wick till sufficient has adhered to it1 then rolling the candle on a marble slab till it is even1 and afterwards polishing with a cloth4 ,,rope4 ,illustration3 ,,spinning ,,the ,,yarn4 ,illustration3 ,,spinning-,,wheel4 ,is a combination of the fibres of hemp or other material1 so arranged as to form a tenacious cord or band1 retaining1 as far as possible1 their collective strength4 ,the first process in rope-making consists in twisting the hemp into thick threads1 called rope-yarns4 ,this1 which resembles ordinary spinning1 is commonly performed by hand1 in a rope-ground or rope-walk1 an enclosed level piece of ground1 about six hundred feet in length1 at one end of which a spinning-wheel is set up1 that gives motion by a band to several small rollers or 8whirls10 each of them furnished with a hook on the end of its axis next the walk4 ,the rope spinner carries a bundle of hemp about three feet long round his waist1 with the fibres all laid even1 and having their ends in front of him1 and from these he pulls out sufficient for the thickness of the 8yarn0 he is spinning1 and after slightly twisting it with his fingers1 attaches it to the hook of a 8whirl10 which is set in motion by the wheel1 and as the fibres are twisted he walks backward1 gradually adding more and more1 a little at a time1 so as to keep the yarn of the same thickness throughout4 ,when the spinner has traversed the whole length of the rope-walk1 he stops1 and another spinner detaches the yarn from the whirl1 and it is then wound on a reel or bobbin4 ,the yarns being spun1 they are next 8tarred0 7if they are to be much exposed to wet1 as for the rigging of ships71 which is done by drawing them through a kettle full of melted tar1 being wound off from one reel on to another1 and the superfluous tar wiped away by means of tow 7rough hemp7 fixed in a hole through which they are drawn4 ,illustration3 ,,hawser-,,laid ,,rope4 ,illustration3 ,,cable-,,laid ,,rope4 ,what is called 8laying0 the rope consists in twisting a certain number of yarns together1 so as to form a strand1 and these strands into a rope4 ,large ropes are chiefly of two kinds1 called respectively 8hawser-laid0 and 8cable-laid10 the latter including only the very largest ropes4 8,hawser-laid0 ropes consist of a certain number of yarns 7according to the size of the rope7 twisted into a strand1 and then three of these strands twisted together4 ,the 8cable-laid0 rope is composed of nine strands1 that is to say1 three strands each composed of three others1 and these composed of yarns1 so that three 8hawser-laid0 ropes1 twisted together1 would make one 8cable-laid0 rope4 ,illustration3 ,,rope-,,making ,,by ,,machinery4 ,laying the ropes and twisting the yarns into strands are both accomplished by the same process4 ,the yarns are attached--in sufficient quantity for the strands--to three hooks1 each turning in the same direction1 while the other ends are collected together and turned in the opposite direction2 the three hooks twist the yarns into strands1 and a hook at the other end twists the strands into rope4 ,of course1 machinery of various descriptions has been applied to rope-making1 and ropes are frequently made entirely by machinery with great rapidity4 ,the annexed cut represents one mode of rope-making by machinery1 in which the yarn is shown being twisted into cord or rope from the reels or bobbins on which it was wound after spinning4 ,,wire4 ,illustration3 ,,coarse ,,wire ,,drawing4 ,illustration3 ,,fig4 #a4 7 ,,metal ,,ingot1 ,,sheet1 ,,strips47 ,illustration3 ,,fig4 #b4 7 ,,large ,,rollers47 ,illustration3 ,,fig4 #c4 7 ,,cutting ,,rollers47 ,illustration3 ,,fig4 #d4 7 ,,close-,,up ,,of ,,cutting ,,rollers47 ,in the manufacture of wire1 the metal from which it is to be made is first cast or wrought into an ingot 7,a1 fig4 #a72 it is then passed between rollers 7fig4 #b7 which flatten it into a sheet 7,b1 fig4 #a71 which is next carried between other rollers 7fig4 #c7 having their surfaces so cut that the projections on one of them fit into the hollows of the other1 forming so many cutting edges or shears 7fig4 #d71 from which the sheet of metal comes forth at ,a1 fig4 #c1 cut into strips or square rods 7,c1 fig4 #a74 ,these rods are then drawn with great force through a plate of hardened steel having a series of holes1 gradually diminishing in size1 bored through it1 which is called the 8draw-plate20 the wire 7of whatever metal it be7 has to be heated red-hot from time to time1 to soften or 8anneal0 it1 for the compression produced by the drawing so hardens it that it becomes brittle4 ,a pair of nippers holds the end of the wire1 and these are moved along a sort of bench by a 8rack and pinion0 7fig4 #e74 ,when all has passed the first hole1 it is drawn through the second1 and so on to the size required4 ,when the wire is pretty fine1 it is attached to a 8cylinder10 which on turning round winds off the wire and at the same time draws it through the plate1 as shown in the engraving1 the wire being made to pass over a small charcoal fire previous to entering the draw-plate4 ,illustration3 ,,fig4 #e4 7 ,,rack ,,and ,,pinion47 ,illustration3 ,,fine ,,wire ,,drawing4 ,different metals have different powers of 8ductility10 that is to say1 some can be drawn much finer than others4 ,dr4 ,turner says1 8,the only metals remarkable in this respect are gold1 silver1 platinum1 iron1 and copper4 ,walliston devised a method by which gold wire may be obtained so fine that its diameter shall be only the #ejjjth part of an inch1 and #eej feet of it are required to weigh one grain2 he obtained a platinum wire so small that its diameter did not exceed the #cj1jjjth of an inch4 ,it is singular that the ductility and malleability of the same metal are not always in proportion to each other4 ,iron1 for example1 cannot be made into thin leaves1 but it may be drawn into very small wires40 ,illustration3 ,,fig4 #f4 7 ,,wire ,,gauge47 ,the sizes of wires are ascertained by a small instrument called a 8gauge10 which is a plate of steel with an opening diminishing to a point in it1 and marks on the sides corresponding to the distance the wire will pass down the notch 7fig4 #f74 ,,cutlery4 ,illustration3 ,,fig4 #a4 7 ,,knife ,,blade47 ,table cutlery is made in the following way4 ,the blade is first rudely fashioned from a flat bar of steel by the hammer and anvil1 and this is then welded to a bar of soft iron half-an-inch square1 and cut off1 leaving sufficient to form the 8shoulder0 or 8bolster10 ,a1 and the 8tang10 ,b1 fig4 #a1 which is first made by the hammer and then beaten into a sort of mould or die4 ,the blade is finished as far as can be done with the hammer1 made red-hot1 and thrown into cold water1 which hardens the steel1 and then 8tempered0 to a full blue color 7see 8,steel07 after which it is fit for grinding4 ,razors and penknife-blades are made of fine steel1 and are forged and hardened as above1 but the tempering is effected by arranging them in rows with their backs downwards on a plate of hot iron till the color appears on their surface indicating the temper they have received1 which for razors is a pale straw color4 ,cutlery is ground upon stones of different sizes1 according to the kind of article2 for saws1 and table-knives1 which are to be ground to a flat surface1 very large stones are used1 while razors1 which have a curved surface1 and penknives1 whose blades are very narrow1 are ground upon very small stones4 ,these stones are driven by machinery with great rapidity1 and are arranged over a trough of water1 so that their lower parts dip into it1 by which plan the stone is kept wet2 if it were used dry1 the steel would get too hot to hold1 and the temper of it be injured4 ,the article to be ground is held at the top of the stone4 ,when ground1 the goods are 8glazed0 by means of a wooden wheel the edge of which is smeared with emery-powder1 and finally1 if they are to be polished 7which is only in the case of the finest steel instruments71 they are held to the edge of a wooden wheel covered with buff-leather1 and charged with 8crocus0--this crocus is a red oxide of iron much used for polishing all sorts of things1 as it is both fine1 free from grit1 and sufficiently hard4 ,illustration3 ,,fig4 #b4 7 ,,balance-,,handle ,,knife47 ,what are called 8balance-handle0 table-knives are those which when laid on the table1 will rest with the blade elevated so as not to touch the cloth 7fig4 #b74 ,the object sought in this arrangement1 is to keep the cloth from being soiled1 and the manner of attaining it is simply by making the shoulder project a little and running a small quantity of lead into the hole of the handle before the 8tang0 of the knife is introduced4 ,the blade and handle or 8haft0 are united by means of rosin1 which is put in powder into the hollow of the handle1 and the tang1 being made hot1 is forced in1 melting the rosin1 and fixing when cool4 ,,nails4 ,illustration3 ,,cutting ,,the ,,metal ,,into ,,slips4 ,illustration3 ,,fig4 #a4 7 ,,nail ,,with ,,shoulder47 ,illustration3 ,,fig4 #b4 7 ,,tack47 ,illustration3 ,,fig4 #c4 7 ,,clasp ,,nail47 ,illustration3 ,,fig4 #d4 7 ,,brads47 ,illustration3 ,,fig4 #e4 7 ,,machined ,,brads47 ,nails are made both by hand and machinery1 the former being called 8wrought10 and the latter 8cut0 nails4 ,for making nails by hand1 a hammer and an anvil only are used4 ,the 8nailor10 having put several rods of iron of the required size into the fire to get hot1 that he may use one after the other1 and so lose no time1 takes one out and with the hammer beats it to a point1 leaving a little shoulder 7fig4 #a74 ,he then places it 7at the part where the dotted line is in the figure7 on a wedge fixed to the anvil1 and with a blow of the hammer divides it2 it is taken up by tongs1 dropped into a hole in the anvil1 and the shoulder beaten flat2 this is called a 8tack0 7fig4 #b71 for a 8clasp nail0 the head is made of a different form by a particular way of striking it 7fig4 #c71 and the form of the hole in the anvil determines whether they shall be square or round2 wrought 8brads0 have the form of fig4 #d4 ,these are the principal forms of nails1 but many others are made by soldering shanks to cast heads1 as coffin-nails1 and some 7chiefly used by gardeners and plasterers for driving into brickwork7 are made of cast-iron4 ,machine-made nails are cut by compression from a sheet of iron4 ,brads are cut out1 simply1 as in fig4 #e1 which uses up the whole of the iron without any waste1 and requires no finishing2 but other forms of nails are cut first into simple wedges1 and have the heads finished afterwards either by the blows of a hammer or by compression4 ,illustration3 ,,cutting ,,brads4 ,most nails are made flat or chisel-shaped at the point1 that they may not split the wood4 ,in driving a nail with a flat point1 the length of the point should be placed across the grain of the wood1 and then it will hardly ever split it1 but if otherwise1 the nail1 acting as a wedge1 opens the grain and splits the wood4 ,,screws4 ,illustration3 7 ,,screw ,,mould47 ,the screws used by carpenters1 smiths1 and others1 for fastening wood or metal-work together1 are generally made by machinery4 ,a piece of wire of the required thickness and length is first cut off1 which is then placed in a hole or mould1 with its upper orifice 8countersunk0 as in the annexed cut1 and the head of the screw is formed by beating the upper part of the piece of wire into the counter-sinking of the mould4 ,it is then called a 8blank10 and a number of these blanks are dropped into holes bored round the periphery of a wheel which revolves slowly against a small circular saw driven with great rapidity1 and cutting a 8thread0 or slit in the head of each blank in turn as it comes into contact with it2 the wheel continuing to revolve1 each screw when it gets to the bottom drops out1 so that the holes when they again arrive upwards are ready to receive fresh blanks4 ,the worm1 if cut by hand1 is made by means of a die of hard steel1 having a hollow screw cut in it1 which is screwed slowly by a backward and forward movement on to the blank1 cutting it into a 8worm20 when this is done by machinery1 the die is held fast while the screw is worked by a rotatory movement into it4 ,the best screws for wood are slightly tapered1 which enables them to be driven much more easily1 while they hold equally fast4 ,large screws for mechanical purposes are cut by a 8lathe10 the bar revolving whilst a cutter is held to it1 and moved onwards by a pattern screw4 ,small screws for various purposes can be easily cut by means of a 8screw-plate10 having holes of graduated sizes cut inside into hollow screws1 which is placed on the end of the wire1 and gently turned round till it is sufficiently cut4 ,,pins4 ,illustration3 ,,pin-,,making ,,machine4 ,illustration3 ,,coil ,,for ,,the ,,heads4 ,pins are made from brass wire drawn out in the usual manner 7see 8,wire-drawing074 ,it is first straightened and then cut off into lengths sufficient for two pins2 these are pointed at each end by holding them to a wheel1 about two or three dozen at a time1 turning them all round at once by means of the thumb and fingers4 ,the wheel is not made of stone1 but of steel1 having the edge cut into fine notches like a file 7see 8,file-cutting074 ,after the wires are pointed at each end1 they are cut in the middle4 ,the heads are made by coiling some brass wire round another piece of wire exactly the size of the pins for which they are intended1 and with a sort of chisel cutting off two of these coils at a time4 ,the accompanying figure represents the coil to be cut up into a string of heads1 and one of them separate4 ,these are fixed on to the pointed wires by a machine acting by means of a lever1 by which they are compressed into the right shape and at the same time made to hold on tightly4 ,the pins are then cleaned by boiling in some weak acid or a solution of tartar1 and have next to be 8tinned0 or 8whitened10 which is done by placing them in layers with grain-tin and cream of tartar1 and boiling them for some time till they are coated with the tin2 thus they are truly 8electro-plated10 although at the time when this process was invented no knowledge of electro-plating existed1 and the theory of the process was not understood4 ,the pins are afterwards cleaned and brightened by shaking them in leather bags with bran1 which is afterwards blown away by a blowing-machine2 the pins are then placed in papers 7folded by a sort of crimping-machine71 which are put into a kind of vice1 having a number of notches cut in it corresponding to the number of pins to be stuck in one row1 and into these notches and through the paper ridges the pins are rapidly passed by children4 ,in some manufactories pins are made entirely by machinery1 and these are the 8solid-headed pins10 or pins which have the head formed out of the same piece of wire as the body1 which is chiefly effected by compression1 and in order that this may be readily done1 the wires are previously softened by heat1 which is one of the principal objections to their general use1 as1 in consequence of this softening1 they bend too readily4 ,,needles4 ,illustration3 ,,drilling ,,the ,,eyes4 ,the manufacture of needles is one of those arts in which manual dexterity is acquired by minute subdivision of labour1 each artisan performing only a small part of the process1 but so often1 that the most wonderful rapidity and accuracy are obtained1 insomuch that although each needle has to pass through nearly #aej hands 7together with expensive machinery7 before finishing1 yet they may be bought at an astonishingly low price4 ,illustration3 7 ,,straightening ,,plate47 ,the following is an outline of the process of manufacture4 ,the wire is first selected1 of the best steel and of a proper size1 then wound round a cylinder some fifty times1 and the coil is cut in two places opposite to each other through all the wires4 ,these wires are placed together in bundles several feet long1 each containing about a hundred wires1 which are then cut up into lengths sufficient for two needles by a pair of shears worked by powerful machinery4 ,as the wires are crooked1 they have to be straightened1 which is done by packing them in bundles and enclosing them in two iron rings so that they may be rolled forcibly backwards and forwards between steel plates with grooves cut in them to receive the projecting rings1 and this straightens them thoroughly4 ,the wires are next ground to a point at each end by holding them1 a dozen or two at a time1 against a revolving stone1 to which they are pressed with a piece of leather1 at the same time turning or twirling them between the thumb and fingers2 when pointed1 they are cut in two by a gauge which divides them in the middle1 and the blunt ends are spread out in the form of a fan on a small anvil by the thumb and finger of the left hand1 several at one time1 and flattened by the blow of a small hammer4 ,this flattening makes the ends too hard for piercing1 so that they have to be softened by being made red-hot and slowly cooled2 they are then pierced by children1 who lay each needle on a piece of lead and with a small punch and hammer strike out the eye1 but in nearly all cases the eye is drilled1 in which case the wire is held for an instant to the point of a small drill turned by machinery4 ,the groove which leads to the eye is made either by the stroke of a small file or by compression1 and the end is next rounded off4 ,in some needles the eyes and grooves are made by punching two in the middle of a wire1 which is afterwards divided4 ,the needles are tempered1 by placing some thousands of them on an iron plate which is made red-hot1 and then throwing them suddenly into a vessel of cold water2 they are by this means made too hard1 and have again to be slightly heated to give the proper degree of temper and toughness 7see 8,steel071 which is done by putting them in boiling oil4 ,they have next to be polished1 and this is the most tedious part of their manufacture4 ,the needles1 to the number of about a hundred thousand1 are packed1 together with oil and emery-powder1 in a strong sort of bag1 so that they all lie side by side1 and several of these bags or bundles are rolled backwards and forwards between wooden beams in such a way that every needle rubs against others1 and the friction thus produced grinds them bright and smooth4 ,after a time they are taken out1 and the black paste formed by the emery-powder1 oil1 and steel1 is cleaned off by putting them into saw-dust1 and turning them in a barrel fixed in a frame for the purpose2 the saw-dust and dirt are then blown away by a blowing-machine1 and the needles again undergo the same process several times1 using finer emery-powder each time1 so as to polish them2 after which they are scoured with soap and water and wiped dry by rolling them in dry wash-leather4 ,they are now perfectly bright1 every roughness rubbed off1 and a finish being finally given to the points by hand on a hone which turns round1 they are packed1 twenty-five in each paper1 for sale4 ,,tubing4 ,tubes of lead and brass are cast in short and thick pieces1 and then drawn through holes in a draw-plate1 similarly to wire1 but having a rod or 8mandril0 passed through the length of the tube to keep the hollow of the right calibre4 ,illustration3 ,,tube ,,drawing4 ,iron tubing for gas and water pipes1 if more than about two inches in diameter1 is cast2 but smaller1 or 8service-pipes10 are made of wrought iron plate rolled on a mandril1 and welded at the edges by being drawn at a white heat through a draw-plate4 ,,steel ,,pens4 ,illustration3 ,,splitting ,,the ,,pen4 ,illustration3 ,,stamping ,,the ,,pen ,,from ,,the ,,steel4 ,illustration3 ,,bending ,,the ,,pen4 ,steel pens1 which have almost superseded quill pens1 are made in great quantities1 and1 like needles and pins1 can only be produced at a sufficiently low price to meet the requirements of the people1 by those who have erected buildings and fitted up machinery so as to make the process sufficiently rapid to be cheap4 ,the steel is first selected of the proper quality1 and rolled out into sheets of the thickness required and of breadth sufficient for the length of the pens to be made2 these are punched out of the proper shape by a punch worked by a screw1 which cuts out a piece at every blow1 and also the perforation which terminates the split4 ,the maker's name or any other device is stamped on this flat piece of steel1 called a 8blank10 which is then coiled up into the shape required 7whether a 8barrel0 pen or a 8nib07 by a sort of press1 worked by a girl1 as seen in the engraving1 and the split made by a machine1 also engraved4 ,in both these machines the screw is worked with the left hand1 while the right is engaged in placing the pens under it and pushing out the pen with the finger after it is bent or slit1 these operations1 from constant practice1 being performed with great rapidity4 ,the pens have next to be tempered1 by being made red-hot and then thrown into water or oil1 and are afterwards polished by putting them into a barrel with fine sand1 which is turned round by a windlass for several hours4 ,the nibs or points are then finished at a stone which turns round1 and a varnish of a brown color--made by dissolving shellac and asphaltum in naptha--is given to the surface to keep them from rusting4 ,sometimes the surface is 8blued10 which is done by heating the pens on an iron plate till the blue color appears 7see 8,steel074 ,pens are sometimes made of other metals besides steel1 as brass1 or zinc1 and sometimes of gold4 ,those made of gold are1 of course1 too expensive for general use1 but as they are never corroded by the ink1 they last a very long time1 and can always be cleaned by washing2 and as the whole wear is at the point1 this is tipped with an alloy which is exceedingly hard4 ,,arts ,,and ,,trade ,,processes4 ,,wood ,,and ,,plate ,,engraving4 ,illustration3 ,,wood ,,engraving4 ,engraving consists principally of two kinds1 that in which the design is made to project1 and that in which it is cut in or indented2 the first kind is used in wood engraving1 and in engraving metallic or wooden blocks and cylinders for calico printing1 the other is called 8plate engraving10 and is used to produce copper1 steel1 and zinc plates for printing4 ,in wood engraving a block of box wood is used1 or several pieces are screwed or tongued together in order to make a block of the required size1 for the box wood must be cut across the grain1 therefore large blocks are not easily procured4 ,these blocks are about an inch in thickness1 so that they may range with type and be printed with it1 they are made perfectly smooth on the face1 which is rubbed with a little flake-white and ,bath brick1 to give it a whitish and slightly roughened surface4 ,on this prepared surface the design is drawn with a black-lead pencil1 and the block is then put into the hands of the engraver1 who cuts away--to the depth of about one-twentieth of an inch--all those parts which have not been blackened by the pencil1 leaving every line and dot of the drawing projecting1 and this serves as a sort of stamp or type1 to print from4 7,see 8,printing407 ,in this way the illustrations to the present work are produced4 ,in plate engraving the design is copied from the original and cut into the plate in a manner quite opposite to that of engraving on wood2 for every line intended to be printed1 instead of projecting1 is cut in with a sharp edge1 so that they may be filled with ink1 instead of being covered1 as in wood engraving4 ,when the design is formed entirely by lines1 it is called 8line engraving10 and when formed by dots1 it is said to be 8stippled10 and these two kinds are often combined in the same plate4 ,there is a process for engraving plates1 called 8etching10 by which the lines or dots on the plate are not made by cutting1 but are corroded or eaten in by the chemical action of nitric acid2 and few plates are now produced by the graver alone1 the design being first etched and afterwards finished off by the graver1 but some are produced by etching alone1 whence they are called 8etchings40 ,the process of etching is as follows3--,the surface of the plate is made smooth and bright1 then heated1 and afterwards coated with a mixture of asphaltum1 wax1 and mastic--called 8etching-ground0--a ball of which is tied up in a piece of silk1 rubbed over the hot plate1 and dabbed with a dabber till a smooth layer or coating is formed all over it2 it is 8smoked0 over the flame of a candle1 to blacken it1 and the result is a smooth black varnish1 which covers the surface of the plate1 and is capable of resisting the action of nitric acid4 ,on this surface the design is drawn with an 8etching-point10 a steel instrument which cuts or scratches quite through the etching-ground1 exposing the surface of the copper at the bottom of each scratch4 ,when the design is finished--in hues or dots1 according to the style required--a ridge or border of wax is made all round the plate so as to form it into a sort of shallow tray1 and into this the nitric acid1 mixed with a little water1 is poured1 and carefully watched till in the judgment of the engraver it has bitten into the plate sufficiently for the fainter parts of the design4 ,the acid is then poured off1 and the plate washed and dried1 after which the parts intended to remain most lightly etched are stopped out with varnish1 and the acid again poured on1 to corrode the lines left exposed to its action more deeply4 ,this is repeated two or three times1 according to the nature of the design1 when the plate is again heated1 to melt the etching-ground1 and the whole is cleaned off with turpentine4 ,the plate may now be used to print from1 or it may be further finished by the 8graver10 8burnisher10 or 8dry point10 which is simply a point of steel used to make very fine and faint scratches instead of cuts1 for the graver cuts out the piece of copper1 while the dry point merely indents it4 ,there is another kind of plate engraving1 called 8mezzo-tinto40 ,this is done by first covering the whole plate with a rough granulated surface--called a 8mezzo-tint ground10--by means of a sort of notched chisel1 called a 8cradle0 or 8grounding-tool10 which is rocked to and fro over the surface in every possible direction1 till the whole is covered with minute dots2 so that if it were then used to print from1 it would produce an even dark surface4 ,on this ground the engraver works with a 8scraper10 scraping gradually away all those parts which are to appear as lights in the finished picture1 and the more the ground is scraped away the lighter will be the tint1 till1 finally1 those parts which are to be quite white are scraped smooth and burnished1 so that they shall hold no ink at all4 ,in this way the engraver proceeds till his design is finished1 trying the effect from time to time4 ,this kind of engraving is often combined with etching1 producing greater sharpness of outline than mezzo-tint alone4 ,,lithography4 ,illustration3 ,,lithographic ,,press4 ,this is the art of producing designs upon stone in such a manner that impressions may be printed from them4 ,it is often miscalled 8engraving on stone20 properly speaking1 it is not engraving1 but a process depending on the want of affinity between watery and greasy matters1 the design being made with a greasy substance1 either in the form of ink or crayon called 8lithographic chalk10 as follows4 ,a close-grained stone called lithographic stone 7a kind of magnesian limestone7 is ground perfectly even on the surface1 and 7if for being written upon7 polished with pumice-stone1 or 7if for being drawn upon with chalk7 grained with fine sand2 the design is drawn with chalk or ink1 each of which is made up of greasy materials--wax1 soap1 and asphaltum1 colored with lamp-black4 ,when the design is made1 the stone is etched--washed over with a weak mixture of nitric acid and water--which answers three purposes2 it very slightly bites away the stone in all places except where it is covered with the ink or chalk1 it smoothes the grain in the same places1 and it converts the soap of the ink or chalk into grease4 ,we have now the surface of the stone quite wet1 except where the design is1 which1 being greasy1 keeps quite dry4 ,the stone1 placed in a press1 is rolled over with a roller smeared with greasy printing ink1 which will not adhere to the wet stone1 but it readily does to all parts of the design2 a piece of paper is placed over the stone1 and a flap of leather covers it2 along this leather the scraper of the press is brought very forcibly when it is worked1 and on removing the paper an impression is found to be transferred to it from the stone4 ,this process is repeated again and again1 many hundred times1 without much injury to the original design4 ,colored lithography1 called chromo-lithography1 is produced by using several stones consecutively 7each transferring a separate color71 so that the design shall be complete when the whole are printed4 ,,printing4 ,the art of printing consists in producing impressions from a pattern or types--cut out and projecting1 or engraved and indented--by smearing the projecting parts or filling up the indented markings with ink1 so that impressions1 to any number1 and exactly resembling each other1 may be taken from them4 ,printing is comparatively a modern invention1 although impressing or taking impressions from seals is one of the very oldest4 ,it is divided into two kinds1 plate-printing and surface-printing4 ,printing from type or blocks having the marks to be impressed raised1 is called surface-printing1 while that in which the lines or marks are cut in1 is called plate-printing4 ,illustration3 ,,printing-,,press4 ,illustration3 ,,inking-,,table4 ,in surface-printing1 when types are used1 they are packed up closely into masses and wedged together in iron frames1 so that they form1 as it were1 solid blocks2 the types or wood-blocks when required to be printed from are placed in the press1 and rolled over by a roller smeared with printing-ink--this roller is coated with an elastic substance made of glue and treacle1 and resembling ,india-rubber4 ,it is worked to and fro on the 8inking-table0 7a smooth iron slab fitted with a receptacle for ink71 in order that the ink may be evenly distributed over its surface--a point to which great care and attention1 and no little skill1 on the part of the workman1 is directed4 ,the ink1 being rolled over the type1 covers and adheres to the surface of the projecting parts4 ,the paper is placed on a frame turning upon a hinge1 and is secured in its place by another frame brought down upon it4 ,these frames1 with the paper1 are now turned down upon the blackened surface of the type1 and the whole--paper and type--passed under the printing press1 where1 by the working of a handle1 a piece of iron is caused to descend and press evenly and with great force upon them4 ,on being withdrawn1 and the frames opened1 the paper is found to have received a perfect impression1 in ink1 of the type upon which it was impressed4 ,this process1 of course1 can be repeated to any extent1 and as many impressions produced as may be required4 ,in plate-printing1 the plate is first warmed1 and all the engraved parts are filled in with ink1 the superfluous ink being wiped off1 and the surface cleaned bright by using a little whiting 7which is rubbed on the hands71 leaving only the indented parts full of ink4 ,the paper 7in a damp state7 is then laid on the plate1 with a fold or two of flannel over it1 and the whole is carried1 by turning the handles of the press1 between two rollers1 which compress the plate and paper together so forcibly that1 when removed1 the ink is found to have left the plate and attached itself to the paper1 forming an impression4 ,printing is now in very many cases done by machinery1 worked by steam power1 so that a very large number of impressions can be produced in a very short time1 as in the case of newspapers1 the whole impression of which 7amounting to many thousands7 is printed in a few hours4 ,printing in colors of various tints1 so arranged as to form a picture1 has lately been much resorted to4 ,the usual method pursued is to print one color1 and when that is dry1 to print the next1 and so on till the picture is complete2 but a machine has been invented by which many colors may be printed at one time4 ,,photography4 ,illustration3 ,,camera ,,for ,,stereoscopic ,,pictures4 ,illustration3 ,,fig4 #a4 7 ,,reduced ,,viewer ,,image47 ,illustration3 ,,fig4 #b4 7 ,,lens ,,arrangement47 ,illustration3 ,,fig4 #c4 7 ,,image ,,transference47 ,the principle of this art depends upon the property which certain chemical preparations 7chiefly those of silver7 possess of being blackened by exposure to light while in contact with organic matter1 and that in so gradual a manner that every degree of shade may be represented4 ,now1 as the various appearances of everything we see depend upon the effects of light and shadow 7together with the peculiar color of the objects themselves71 it follows that if these lights and shadows can be transcribed1 we shall have a representation of the objects1 minus their own proper colors--and this is what photography effects4 ,for the purpose of bringing the objects to be taken within a small compass1 and for increasing their vividness1 an instrument is used called a camera1 in which there is an achromatic arrangement of lenses 7shown in figs4 #b and #c71 which produces a picture on the paper or glass to be affected by the light1 in the same way that a common magnifying glass will1 if held at a proper distance from a piece of paper1 but much more perfectly 7fig4 #a74 ,the effect of this camera-picture on the paper or glass when properly prepared and subjected to its influence1 is to darken the paper in all those parts which in the camera-picture are the brightest1 and to leave unaffected those parts which are the darkest1 thus producing what is called a 8negative picture10 having the lights represented by shadows and the shadows by lights4 ,this is used to form the true or 8positive0 picture1 which is done by placing the negative on a piece of prepared paper1 and exposing it to the light4 ,the negative having been made partly transparent by wax 7as will be further explained71 and the parts of the picture which are to be dark being left transparent1 the light passes through them and blackens those parts of the prepared paper behind1 while those which are to be light1 being dark in the negative1 exclude the light and thus preserve the paper at the back from being darkened2 the paper is thus affected in the contrary way to the negative1 and is therefore a true picture of the lights and shadows of the object copied4 ,this is the principle of all photographic pictures1 but with numberless variations in its practice2 it would therefore be impossible here to describe the particulars of each process1 beyond the most simple4 ,illustration3 ,,fig4 #d4 7 ,,photographic ,,plate47 ,perhaps of all the various arts discovered by man1 this is the most beautiful1 producing a perfect likeness of any being or object in a few moments1 and with a truth not to be equalled by years of study and practice in other ways4 ,one of the earliest discovered and simplest modes of forming a sun picture consists in using the object itself 7where this is possible7 to form the negative4 ,this can only be done when the object is flat1 as a manuscript1 a picture1 a leaf1 or a piece of lace-work2 a piece of paper washed over with a solution of common salt1 dried1 and again washed over with a solution of nitrate of silver1 will answer for this purpose2 it should be prepared by candle-light1 as daylight blackens it1 and it should be kept from the light till the moment for use4 ,if this paper1 having the object to be copied placed on it and kept flat by a piece of glass pressed firmly on by a contrivance shown in fig4 #d1 be exposed to the sunshine1 it will be blackened in all places but those kept from the light by the darker parts of the object1 and the lights and shadows will vary accordingly as the various parts of the object itself are more or less transparent4 ,when the effect has been produced to a sufficient degree1 the paper should be removed and at once washed in a solution of hyposulphite of soda1 which removes all the superfluous silver 7which otherwise would be darkened by the light72 when removed from the hyposulphite of soda it should be well soaked in clean water4 ,this when finished is a true negative picture of the object1 and can be used to produce the positive4 ,the negative should first be made partly transparent by brushing it over with some melted white wax1 then placing it between folds of blotting paper and passing a hot iron over it1 the blotting paper will absorb all the superfluous wax1 and the negative will be fit for use4 ,a piece of paper prepared like the first with salt and nitrate of silver1 should be placed against the front of the negative1 kept smooth by a piece of glass1 and exposed to the sunshine for a quarter of an hour or more1 taking care that the back of the negative is exposed to the light and the prepared paper behind2 a positive picture will be produced1 which is to be at once treated with a solution of hyposulphite of soda and washed with clean water1 as was the negative4 ,any number of positive impressions may thus be produced4 ,the 8,calotype0 or 8,talbotype0 process may be performed as follows1 recollecting that all these processes must be conducted by candlelight1 or in a room having the window covered with yellow silk1 or some other substance excluding white light4 ,select a piece of paper of an even surface and structure1 such as ,whatman's paper1 brush it over with a solution of nitrate of silver--about sixteen grains to an ounce of water--and let it dry1 then fold up the edge of the paper all round and dip the surface to which the solution of nitrate of silver has been applied into a solution of iodide of potassium--an ounce to a pint of water--contained in a shallow vessel1 and let it partly dry2 float it for a quarter of an hour in a vessel of clean water1 moving it gently about so as to remove all soluble matter1 and hang it up by a corner to dry1 taking care to let nothing touch the surface4 ,when about to be used1 this paper must be brushed over 7using a soft camel-hair brush7 with a mixture1 in equal quantities1 of a solution of nitrate of silver--fifty grains to an ounce of water--and a saturated solution of gallic acid1 forming what is called the 8gallo-nitrate0 of silver4 ,leave this solution on the surface for ten minutes1 and again immerse the paper in two or three successive portions of pure water1 moving it to and fro2 this1 when nearly dry1 is in a fit state to place in the camera1 and is an exceedingly sensitive paper1 which in a good light will be affected in a few seconds4 ,when the image has been impressed by the camera1 the paper should again be brushed over with the gallo-nitrate of silver1 and held either near a fire or a plate of hot iron1 so as to receive a gentle warmth2 the impression will now come out1 of a deep rich colour4 ,dip it into warm water for a few minutes1 and put it into the hyposulphite of soda bath--an ounce to a quart of water--from which it is finally removed and placed in a large vessel of pure water for several hours4 ,when dry1 it is complete1 forming a good negative1 which1 when waxed1 may be used to print positives as before described4 ,the 8,collodion0 process is conducted as follows4 ,having selected a plate of glass of the required size and of good quality 7patent plate answers well71 clean it thoroughly with rottenstone and spirits of wine1 and polish it with a clean dry linen cloth2 then hold it on the tips of the fingers and thumb in a horizontal position1 pour upon it a small quantity of the 8iodized collodion10 and so incline it from side to side1 that all the surface shall be covered with the collodion1 that which is superfluous being returned to the bottle by pouring it from one corner of the glass4 ,in a few minutes the coating of collodion will be dry1 and should form a perfectly even surface1 without air spots or uneven markings4 ,the iodized collodion is made by dissolving gun-cotton in ether1 and adding spirit of wine and iodide of ammonia4 ,the glass plate coated with collodion is now dipped into a solution of nitrate of silver--thirty grains to an ounce of water--and allowed to remain two or three minutes2 when all the superfluous fluid has drained off1 the plate is ready for use1 and is extremely sensitive to light4 ,when the impression has been produced by the camera1 a solution of pyro-gallic acid1 mixed with a little acetic acid1 is poured over the surface1 which brings up the image2 when this is developed to a proper extent1 the surface must be washed with clean water and afterwards with a solution of hyposulphite of soda1 which dissolves out all the silver from those parts not darkened by the light in the camera1 leaving the glass in those parts quite transparent4 ,a negative is thus obtained fit to print from in the usual way1 but glass being more transparent than the waxed paper1 it produces a more perfect positive4 ,the surface thus prepared should be coated with a varnish1 made by dissolving amber in chloroform1 which is done by pouring it on and decanting the superfluous varnish similarly to the mode of coating with collodion2 this varnish dries in a few minutes1 and preserves the surface from injury4 ,sometimes these negatives are converted into positives1 instead of being used to print from2 in these cases the surface is coated with black japan1 and the collodion1 having a whitish surface1 owing to reduced silver1 shows up in comparison with the black varnish which is seen through the transparent parts4 ,these positives are extremely sharp and well defined4 ,the 8,daguerreotype0 process consists in forming the image on the surface of a metallic plate 7copper coated with silver71 which is first polished to a perfect surface like a looking-glass1 then exposed to the vapour of iodine in a properly-constructed box1 afterwards to the vapour of chloride of bromine1 and again to the vapour of iodine2 this produces a thin film of a mixture of bromide and iodide of silver1 which covers the surface of the plate1 and is very sensitive to light1 which reduces the iodide and bromide to the metallic state in a few seconds4 ,the plate is then exposed to the action of the light in the camera1 and when sufficiently affected1 exposed to the vapour of mercury1 the mercury being put into a box1 and heated by a spirit lamp2 the mercurial vapour adheres to all the parts of the silver reduced by the light1 and forms a light-coloured amalgam1 corresponding to the lights of the objects represented4 ,the plate is then washed with a solution of hyposulphite of soda1 which removes all the bromide and iodide of silver not reduced by the light1 and exposes the highly-polished surface of the silver1 which forms the shadows of the picture2 this is now 8fixed0 with a very weak solution of chloride of gold and hyposulphite of soda1 which is poured over the surface and heated while there by applying the flame of the spirit lamp to the back of the plate for a minute or two2 the solution is then poured off1 and the picture when washed with water is complete4 ,,illustration3 ,,fig4 #e4 7 ,,stereoscope47 ,illustration3 ,,fig4 #f4 7 ,,stereoscopic ,,slide ,,box47 ,many photographic pictures1 whether ,talbotype or ,daguerreotype1 are taken double for the 8stereoscope0 7fig4 #e74 ,this is an instrument having two lenses 7one for each eye71 through which the two views may be seen4 ,the principle is this3--,every object is seen by each eye in a slightly different view2 for instance1 if you look at the edge of a print--placing the printed part towards your right hand1 and bringing the edge in front of the lace between the two eyes--by closing the right eye1 the left will see the back of the print only1 but by closing the left eye the front of the print may be seen1 and the front only4 ,the stereoscope presents both of these views to the eyes at once1 as when we look with both eyes1 and the objects have therefore the appearance of projecting1 as do read objects4 ,to take these views1 the slide after one view is taken is moved about four inches on one side1 and then the other is taken2 the distance moved corresponds to the distance between the eyes1 and therefore produces the correct view for each4 ,the box for the stereoscopic slide is shown at fig4 #f1 in which ,a is the first view to be taken1 while the other half of the glass is kept dark1 at ,b1 and ,c is the shutter for ,a4 ,,book-,,binding4 ,illustration3 ,,fig4 #a4 7 ,,sewing-,,press47 ,the sheets of which a book is to be made1 when properly folded 7into half for folio1 quarter for quarto1 c47 are pressed flat in a press and then placed1 one or more at a time1 on a board behind a frame called a 8sewing-press0 7fig4 #a71 which has pieces of string or cord 7called bands7 tied in an upright position1 and against these the folded edge of the sheet is brought in such a manner that the bands may be sewn on to the back of the sheet by a thread being passed from the inner part of the folded sheet to one side of the string1 then in again on the other1 and so on for each cord till they are fastened on to the first sheet1 when another is placed on the top of the first and sewed in the same way4 ,illustration3 ,,fig4 #b4 7 ,,plough47 ,when all are sewn1 the back is glued thickly over1 and the book is fixed between two boards in a press and the back beaten till it is curved2 the sides and front are then cut smooth with an instrument called a plough 7fig4 #b71 which works in the grooves of a press where the book is fixed1 and a knife 7which forms part of the plough7 being passed backwards and forwards1 cuts through the edges of the book and makes them smooth4 ,illustration3 ,,fig4 #c4 7 ,,cutting ,,with ,,shears47 ,illustration3 ,,fig4 #d4 7 ,,engraved ,,tools47 ,the covers--made of a thick pasteboard called 8millboard10 and cut to the right size by shears 7fig4 #c7--;are fitted to the sides of the book1 the ends of the string-bands are then passed through holes in the sides of the boards1 and are beaten flat and glued down4 ,the book is then covered with cloth1 vellum1 paper1 or leather1 as desired1 and finally pressed in a powerful press to make the leaves smooth4 ,ornaments1 such as gilt bands or corner decorations1 are produced by gold-leaf put on and stamped by means of tools engraved at their ends1 or1 where the margin is to have a pattern or line on it1 by means of wheels with engraved edges 7fig4 #d74 ,leather-backed books are glazed on the outside with white of eggs1 which forms a kind of varnish when dry4 ,illustration3 ,,fig4 #e4 7 ,,book ,,mould47 ,illustration3 ,,fig4 #f4 7 ,,glued ,,backing47 ,illustration3 ,,fig4 #g4 7 ,,sewn ,,backing47 ,books have lately been bound without any sewing1 by 8,hancock's ,patent0 process4 ,this consists in having all the sheets folded into double leaves1 and the folded parts all brought evenly to a curved form for the back of the book by means of a mould or hollow cut in the edges of two upright boards 7fig4 #e72 they are then removed to a press which holds the book tightly together1 leaving this curved back just projecting in front of the press-boards4 ,the back is smeared with ,india-rubber dissolved in naptha1 which when dry is several times repeated1 till a coating of sufficient thickness is produced1 when it is covered with cloth or linen and the book is ready to be finished in the usual way2 thus the sewing is quite dispensed with1 for the folded edge of each sheet is held to the next one by a thin coating of ,india-rubber4 ,this plan allows great freedom in opening1 and for thick books produces a level surface much superior to those bound in the old way 7figs4 #f and #g74 ,,paper-,,staining4 ,illustration3 8,,grounding0 ,,the ,,paper4 ,this name is given to the process for making paper-hangings for the decoration of the walls of apartments4 ,the colors used in this process are all what are called body-colors1 or those which are not transparent1 but mixed with whiting or prepared chalk and a small quantity of size to the required tint4 ,the colors are applied by means of wooden blocks having their surfaces so engraved that the pattern shall project2 all the pattern is not engraved on one block1 but only that part of it which is to be of one color1 and the number of blocks required depends upon the number of colors in the pattern--usually three or four4 ,the paper is printed in pieces of about twelve yards in length2 these are first 8grounded10 that is1 colored all over with the color intended to form the ground of the pattern1 and hung on poles to dry4 ,the blocks are applied to a sort of sieve1 with a leather bottom1 on which some color is spread with a brush1 and when the block is taken up sufficient of the color adheres to give a good impression on the paper4 ,each block has a register1 which produces a little mark at the edge of the paper1 and serves as a guide in applying the succeeding blocks1 so that when printed they fit into and correspond with each other4 ,illustration3 ,,printing ,,the ,,pattern4 8,flock0 paper is produced by printing part of the pattern in a varnish of boiled oil and whiting1 and laying the paper so printed in a trough or tray over which the flock is sprinkled4 ,the flock is made by grinding shreds of cloth of the required color in a mill4 ,this rough surface gives a very rich and velvety appearance to the paper4 ,,flax ,,manufacture4 ,flax1 before being spun into 8yarn0 for weaving linens1 undergoes several processes1 to separate its fibres sufficiently1 and to rid them of all short and uneven portions4 ,the first operation consists in a kind of fermentation called 8retting10 the stalks of the flax being packed up in bundles and steeped in water1 or exposed to damp air1 spread out1 till they soften and become fit for the next process1 called 8breaking40 ,this is done by contrivances which beat and bruise or give it several sharp bends1 the object being to break off the outer part1 called the 8boon10 and leave the inner fibres or 8harl0 free2 this1 which is the part to be used1 is thus in a great measure freed from the outer part1 but to do so completely it is scraped with a blunt kind of knife till all the 8boon0 is gone4 ,the next process is called 8heckling10 a sort of combing1 in which the flax is dragged through brushes of fine iron spikes1 used closer and closer till the flax is combed out quite fine and perfectly free from knots or uneven pieces1 being beaten from time to time to break or separate the fibres4 ,during this process much of the short and uneven fibres collect in the 8heckle10 and is called 8tow10 which has to be separated and the fibres arranged similarly to 8carding0 cotton 7see 8,cotton ,manufacture074 ,the flax has now to be drawn out1 doubled1 and drawn out again into 8slivers10 also in the same way that is described for drawing out cotton1 and these slivers are finally twisted into yarn1 being previously wetted to take off their stillness4 ,the yarn is then wound upon bobbins1 forming the material from which linens1 muslins1 and other goods are woven4 ,,glass-,,painting4 ,illustration3 ,,cartoon1 ,,or ,,designing ,,room4 ,illustration3 ,,painting4 ,of glass-painting there are two kinds1 the one being known as 8painted10 and the other as 8stained glass40 ,in the former the design and coloring are produced by the application1 to the surface of colorless glass1 of transparent pigments of various colors1 which1 under the action of the furnace1 become vitrified and incorporated with the body of the glass4 ,in this manner of glass-painting--which is capable of none of the powerful and rich effects of color peculiar to stained glass--it will be understood that the process much resembles the practice of the picture painter4 ,in the one case canvasses are used1 and in the other sheets of colorless glass2 the picture-painter using colors mixed with oils and varnishes1 the glass-painter colors made of earths and metals1 and mixed with a flux1 which1 under the action of fire1 vitrifies his work4 ,it is quite possible to produce a large composition1 containing many figures and a great variety of colors1 on but few pieces of glass4 ,indeed1 one of the necessities of making a window of 8painted glass0 in several pieces1 is simply to avoid the danger of breakage1 in using sheets of too large a size4 ,the various pieces are joined together with lead work of precisely similar nature to that which is used in the diamond 8quarry-glass0 seen in the windows of country cottages4 ,illustration3 ,,cutting ,,room4 ,illustration3 ,,glazing ,,the ,,work ,,up4 ,illustration3 ,,furnace4 8,stained glass0 differs from glass-painting in very many particulars4 ,in this case the colors1 instead of being laid on with a brush as in painted glass1 are formed in the substance of the glass itself4 ,this necessitates the use of separate pieces of glass for every color or tint required1 and thus the process in some degree resembles that of mosaic work1 a term1 indeed1 which is often applied to this kind of glass-painting4 ,the first process in producing a stained glass window is the making of the design1 colored or otherwise4 ,this office is1 of course1 that of the artist1 who is at the head of his establishment4 ,from his design1 which is always made to a small scale1 the full-sized drawings or cartoons are made1 by the artist and his assistants4 ,when finished1 with all details and colors determined1 they are placed in the hands of the glazier1 who cuts with his diamond the glass of the required shapes and colors1 respectively1 so that when his task is complete1 the window1 as laid out on the 8cutting-board10 much resembles a child's puzzle--each piece of glass1 although often of the most complicated form and minute size1 fitting with accuracy to the other pieces by which it is surrounded4 ,this process completed1 the next course is for the painter to produce on the blank piece of colored glass prepared for him by the glazier the various outlines and shadings1 as represented in the cartoon1 it being his business to take such means as will ensure the production of a faithful copy4 ,this outlining and shading is produced by the use of a brownish or warm grey tint1 which is generally used a little over all the colors represented in the work4 ,there are some slight gradations of these brown tints used occasionally1 principally when it is desired to paint the flesh shadows with some separate tint1 but generally it may be understood that the office of the painter in stained glass is not to produce the colors1 but by his brown shadowing to bring out the design and forms of the composition4 ,when the glass1 thus shaded and outlined1 has passed through the furnace--where the shadows are vitrified--and been allowed gradually to cool1 the glazier fits it together with lead-work1 soldering in all the pieces1 then the whole is made weather-tight1 and the stained glass window is complete4 ,,cotton ,,manufacture4 ,illustration3 ,,mule ,,frames4 ,illustration3 ,,french ,,combing-,,machine4 ,illustration3 8,,scotching0 ,,or ,,blowing ,,machine4 ,illustration3 ,,lap ,,frame4 ,illustration3 ,,carding ,,machine4 ,illustration3 ,,drawing ,,machine4 ,after the cotton is sorted1 and the grosser impurities picked from it by hand1 it is dressed by the 8combing machine10 or subjected to a machine 7called a 8willow10 as it was originally a sort of basket7 contrived to open out and mix the cotton well together1 at the same time blowing off all dust and allowing the heavier impurities to fall through a grating4 ,the next process is called 8scotching10 and the machine is sometimes called a 8blowing machine40 ,from this the cotton is passed in a 8lap0 or thin layer1 which is beaten as it passes1 to get rid of dust1 and a draught of air produced by a blowing apparatus assists in the same object2 it is thus entirely freed from all impurities4 ,the cotton is then carried to the 8carding machine10 for the purpose of having its fibres all laid parallel with each other2 this machine is1 in fact1 a sort of comb1 and consists of cylinders having fine wires projecting from their surfaces acting in different directions1 so as to draw out the fibres till they all lie in one direction1 forming a kind of 8fillet10 called a 8card10 which is carried by rollers into a tin can and then subjected to a process called 8drawing and doubling40 ,as the 8card ends0 are not yet sufficiently parallel in their fibres1 they have to be passed between three sets of rollers1 the undermost of which are fluted on their surfaces1 the upper ones being covered with flannel4 ,these rollers act in a peculiar manner2 the first pair pass the cotton at a certain rate on to the second pair1 which would pass it on to the third unchanged if they revolved at the same rate as the first pair1 but they are turned a little faster1 and therefore stretch the fillet of cotton at an even and regular rate1 and in such a manner that it is not broken2 the third pair1 going faster than the second1 again stretch the fillet4 ,after the fillet has passed through it is doubled1 passed through again and again1 till it is quite uniform in its structure1 and drawn out by these stretchings very fine1 it is then called a 8sliver40 ,when it is drawn as fine as the kind of cotton admits1 the first twist is given to it by the 8roving0 machine1 which twists it into a soft card1 delivers it wound on 8bobbins10 and it is finally twisted into yarn by the 8winding machine40 ,illustration3 ,,bobbin ,,frame4 ,illustration3 ,,winding ,,machine4 ,these processes are carried on with great precision and rapidity1 and1 by the aid of these machines1 one man is able in a day to produce as much yarn as the most expert spinner by hand could furnish in a year6 ,cotton1 until about #agfj1 was all spun by hand4 ,a little later1 ,james ,hargreaves invented the 8spinning-jenny10 and ,arkwright afterwards improved the 8carding machine20 the 8mule-jenny0 7see ,heading71 invented by ,crompton1 was a still further improvement4 ,the cotton1 when spun1 is called yarn1 which is used for weaving into calicoes and other cotton goods4 ,cotton thread is made by twisting 7by machinery7 two or more yarns into one1 which are afterwards dressed with starch1 and wound on reels or into balls4 ,,woollen ,,manufacture4 ,wool is almost exclusively derived from the fleece of the sheep1 goats' wool being only occasionally used4 ,wool differs from hair in possessing a notched surface1 giving it the very useful quality of 8felting10 and enabling the fibres to adhere into a mass when pressed and beaten together1 the notches catching into each other4 ,woollen articles are chiefly of two kinds1 8woollens10 or those partly felted and made from 8short0 or 8clothing0 wools1 called 8cloths10 and those made without felting from 8combing0 or 8long0 wools1 as 8merinos10 8stuffs10 c4 ,wool undergoes a numerous succession of processes before it is complete in its manufacture4 ,it is first sorted according to the quality required1 next scoured and washed in a warm solution of soap1 and then rinsed in cold water1 to get rid of the 8yelk0 or grease with which the wool is naturally coated4 ,it is then passed between rollers to dry it1 next dyed1 and then 8willowed0 7this last process is to disentangle the fibres and at the same time get rid of any dust which may have been mixed with it72 afterwards it is spread out and sprinkled with a small quantity of olive oil being thoroughly beaten with rods1 to spread the oil over the surface of every fibre4 ,it next undergoes a process called 8scribbling10 which is effected by a machine which combs out the fibres and lays them in layers1 in a parallel direction2 the wheels which effect this are armed on their surfaces with wires and the wool passes from one set to another1 finer and finer1 till at last it passes out in threads or 8cards0 and these are spun by the 8slubbing machine0 into 8yarns0 for weaving4 ,after being woven1 the oil is again washed out with warm soap and water1 and the fabric is then stretched by means of 8tenter-hooks0 stuck in a margin or 8list0 of coarser worsted1 left on each side of the cloth for that purpose1 and it is allowed to dry in this position4 ,the material is now fit for 8felting10 or 8fulling10 as it is called1 which is done in the 8fulling mill40 ,the process consists in thoroughly beating the cloth with heavy wooden mallets or 8stocks0 for ten or twelve hours1 it being at the same time wetted with soap and water1 and folded into a mass of many layers4 ,this beating causes the fibres to interlace and adhere together till the cross-bar pattern made by the warp and weft in weaving is obliterated1 and the cloth has the appearance of a felted surface1 which1 however1 is rugged and uneven4 ,it is next 8teazled10 a process formerly performed by means of a bundle of thistle-heads--called 8teazles0--which were dragged over the cloth1 so as to raise the ends of the woollen fibres perpendicular to the surface2 but this is now performed by machinery1 the teazles being fixed round a roller turning one way1 while the cloth is moved in an opposite direction4 ,in some machines wire brushes are used instead of teazles4 ,the cloth is next 8milled10 or 8sheared10 which is done by stretching it out on a perfectly level surface1 where a pair of circular knives fixed to a wheel work over it and 8shear0 off the fibres1 leaving the surface perfectly even4 ,it is now wetted1 brushed1 and finally dried and packed in a finished state4 ,,weaving4 ,the art of weaving threads of various descriptions is one of the oldest1 and is frequently mentioned in the ,scriptures and other ancient records4 ,it consists in so crossing or interlacing the fibres that they shall form fabrics fitted for the various requirements to which they are applied4 ,weaving1 as now performed by machinery1 for the production of what are called 8textile fabrics10 is far too complicated to be here described in detail1 the machines which are used being amongst the most complicated contrivances of men's hands4 ,dr4 ,ure says of the weaving of 8bobbin-net10--8,it may be said to surpass every other branch of human industry in the complex ingenuity of its machinery2 one of #8,fisher's spotting-frames' being as much beyond the most curious chronometer as that is beyond a common roasting-jack40 ,the principle is1 however1 nearly the same1 whether performed by hand or by machinery1 but some of the more complex fabrics could only be produced by hand1 and by those few who may have devoted great talents and years of application to the acquirement of the requisite skill1 whereas a machine once made can be imitated by ordinary workmen1 and itself worked by unskilled mechanics4 ,illustration3 ,,fig4 #a4 7 ,,linen ,,weave47 ,illustration3 ,,the ,,jacquard ,,loom4 ,illustration3 ,,fig4 #b4 7 ,,heddle ,,raised47 ,illustration3 ,,fig4 #c4 7 ,,shuttle47 ,illustration3 ,,fig4 #d4 7 ,,twilled ,,fabric47 ,in plain weaving1 as in fig4 #a1 of which linen or calico may be the examples1 the yarn or threads simply cross each other1 going alternately above and below4 ,the thread which runs from end to end of the cloth is called the 8warp10 and that from side to side the 8weft0 or 8woof40 ,in nearly all wearing the weft is the same1 but in 8figured0 or 8twilled0 fabrics the warp is so arranged that a pattern shall be formed1 as is seen on towels1 table-cloths1 c4 ,in plain weaving1 the threads are first wound off1 of the required quantity and length1 on a frame called a 8warping frame20 they are then wound on a roller1 side by side1 and attached to the 8loom10 or machine for weaving1 through which they run1 also side by side4 ,near the end they are attached to what are called heddles1 which consist of threads stretched in an upright frame1 having loops near their centres2 a pair of these is used in plain weaving1 one half of the warp threads being attached to the loops of one1 and the rest to those of the other heddle1 alternately1 thus--first a thread through a loop of one heddle1 then another through a loop of the other heddle1 and so on4 ,these heddles can be raised alternately by a pulley attached to treadles worked by the weaver's feet1 and it follows1 that when one of the heddles is raised1 every alternate thread of the warp is raised also1 a space of a triangular form being left 7fig4 #b74 ,through this space the weaver throws the 8shuttle0 7fig4 #c71 which is a piece of wood pointed at each end1 bearing a reel of 8weft0 in its centre1 which weft-thread unwinds as it is thrown through4 ,the other heddle is then raised1 and the shuttle thrown back again1 each time leaving a line of weft behind it4 ,in this way the crossings of all plain fabrics are produced1 a contrivance being used between each throw to press the weft close to the former one4 ,if instead of one half of the warp-threads being up and the other half down at the time the shuttle is thrown1 one only is raised at every fifth thread1 the intervening four being down1 and the one that is raised differing at each throw of the shuttle1 a kind of structure is produced called 8tweeled0 or 8twilled10 such as satin1 bombazine1 c42 fig4 #d shows the appearance of the edge of such a structure4 ,if the warp consists of alternate threads of different colors1 white and blue for example1 it is clear that either color will predominate where the warp thread of that particular color is most seen4 ,in fig4 #e1 a a a a represent white1 and b b b b blue threads1 and this will show how the pattern on any structure1 although the same on both sides1 is blue on the one side where it is white on the other1 as in damasks1 or raised on one side where it is sunk on the other1 as in dimity1 or diaper4 ,illustration3 ,,fig4 #e4 7 ,,dual ,,color ,,weave47 ,,bleaching4 ,illustration3 ,,bleaching ,,works4 ,the chief object of bleaching is to get rid of the natural coloring matter which always tinges cotton1 silk1 c41 as produced from the raw material1 and also to get rid of any greasy matters1 or stains from accidental causes4 ,cotton is not only required to be bleached when intended to remain white1 but also before dyeing or printing1 the colors being thereby rendered more uniform and brilliant4 ,the oldest method of bleaching consisted in simply exposing the goods1 moistened with water1 to the action of light and air1 by spreading them out on the grass1 and hence the term 8grass-bleached20 but this is by far too tedious a process for the present day1 when the manufacture is so great and the consumption so rapid4 ,the process of bleaching cotton goods consists in boiling them first in water1 then in a mixture of lime and water1 and then in a solution of soda1 soaking them in a solution of chloride of lime1 afterwards in water acidulated with sulphuric acid1 and finally in pure water4 ,linens are chiefly bleached by repeated boilings in solutions of potash or pearlash1 and afterwards in chloride of lime2 wool by soaking in warm water1 exposing it to the vapour of sulphur1 and finally washing in a solution of soft soap4 ,illustration3 ,,singeing ,,apparatus4 ,illustration3 ,,drying ,,apparatus4 ,before being printed1 it is necessary that all the loose fibres should be removed from the surface of the goods4 ,this is effected by 8singeing10 which is done by causing the goods to pass over a red-hot roller1 setting fire to the fine fibres projecting from the surface only1 but with a motion too rapid to allow the fabric to be scorched4 ,this process1 and also the apparatus by which the articles are dried after bleaching1 are shown in the accompanying illustrations4 ,the latter consists of a series of hollow rollers heated by steam1 over which the goods to be dried are passed1 a current of air being admitted to carry off the vapour4 ,,calico-,,printing4 ,illustration3 ,,calico-,,printing ,,works4 ,illustration3 ,,fig4 #a4 7 ,,printing ,,schematic47 ,calico-printing is executed either by hand 7with wooden blocks having the pattern engraved--projecting--on their surfaces7 or by means of machinery4 ,printing by hand-blocks is a tedious operation1 and is now almost superseded by the cylinder4 ,the hand process is very similar to that made use of in paper-staining 7which see74 ,cylinder-printing is a much more rapid process1 conducted by means of a brass cylinder with the pattern engraved on its surface1 which is made to revolve against another cylinder covered with flannel1 and charged with color from a trough into which its lower part is dipped4 ,the calico is passed over a large cylinder made to revolve in contact with that on which the pattern is engraved1 and which is charged with color from the one below it4 ,fig4 #a shows this arrangement1 a being the large cylinder with the calico round it1 b the engraved cylinder1 c the color cylinder1 and d the color trough4 ,as the engraved cylinder revolves1 it prints the pattern at each revolution1 and this is repeated again and again1 to the whole length of the piece of calico4 ,in some machines there are several engraved cylinders1 each printing its own color1 and so arranged that the colors shall fit into the parts of the design requiring them1 the whole making up the complete pattern4 ,illustration3 ,,ageing ,,process4 ,illustration3 ,,drying ,,room4 ,before being printed1 the calico is prepared by being passed through a preparation1 called a mordant1 capable of fixing the colors1 and preventing them being washed out1 and several of these are used1 according to the colors required4 ,the colors are thickened with paste1 so as to prevent them from running into each other when printed4 ,muslins1 chintzes1 c41 are printed in a similar manner to calicoes4 ,when the pieces of calico come from the printing cylinders1 they are made to pass upwards through holes in the ceiling to a room above1 where they pass over surfaces of iron heated by steam1 so as to thoroughly dry them2 they then descend through the floor into the printing room1 where they are packed4 ,the process called 8ageing0 consists in exposing the calicoes to the air for a certain time1 to take off the harshness and stiffness peculiar to new goods4 ,in some cases the colors themselves are not printed on the goods1 the mordants being used instead1 and the whole piece is then boiled in a vat of dye-stuff1 which1 however1 only adheres to the parts printed with the mordant1 all the rest being easily got rid of by simple washing4 ,,dyeing4 ,illustration3 7 ,,dyeing ,,process47 ,the art of dyeing does not simply consist in coloring the different substances2 if this were the case1 the color would be washed out as easily as imparted4 ,nearly all the colors used in dyeing being of vegetable origin1 it is necessary to apply some substances to the fabrics to be dyed which shall fix the colors in the grain4 ,of these 7called 8mordants07 the chief are acetate of alumina1 acetate of iron1 and chloride of tin 7substances well known to chemists71 which have the property of making the coloring matter insoluble1 so that it cannot be washed out4 ,there are various ways of dyeing4 ,if the fabric has to be dyed all one color1 it is dipped in the mordant1 dried1 and afterwards boiled in a solution of the dye-stuff4 ,if a colored ground with white figures is required1 then the figures are printed on it with what is called a 8resist10 that is1 some substance thickened with gum1 paste1 or pipe-clay1 which will resist the action of the mordant and dye-stuff1 so that when the fabric is afterwards rinsed these figures remain white4 ,if the ground is to be white and the pattern dyed on it1 then this is printed with the mordant and the color adheres only to the parts printed1 although the whole be boiled with the dye-stuff1 what little may adhere to the ground being easily washed out in the rinsing4 ,sometimes the kind of mordant used determines the color of the dye2 for instance1 madder will dye red with the chloride of tin1 and black with the acetate of iron4 ,if we now suppose a piece of cloth to be printed in lines of acetate of iron1 and figures of chloride of tin1 when the whole is boiled in the madder vat1 the cloth comes out with black lines and red figures on a white ground4 ,another point to be considered is the kind of stuff to be dyed1 whether cotton1 silk1 or woollen1 or a mixture of either1 for what will take one kind of dye will not always take another1 and advantage is taken of this to dye two colors at once1 or part white and part colored4 ,a table-cover1 for instance1 woven with worsted and cotton1 can be boiled in various kinds of dye1 and produce white and blue1 or white and red1 for that dye is selected which will attach itself only to one kind of fabric1 and leave the other4 ,illustration3 ,,scouring4 ,many other chemical qualities of the substances used as dyes1 and of the substances to be dyed1 are also taken into consideration4 ,one of the chief of these is shown in dyeing with indigo4 ,this substance 7a vegetable extract7 as brought to ,england is quite insoluble in water and unfit for use as a dye2 but it is made soluble1 and at the same time almost colorless1 by mixing with lime1 sulphate of iron1 and water4 ,these substances deprive it of its oxygen1 and the straw-colored solution is then used for dyeing1 the substances boiled in it attaining--as the indigo regains its oxygen on exposure to the air--a deep blue color4 ,with dyeing is often associated the art of 8scouring10 for a knowledge of the properties of the dye-stuffs used enables the workman to discriminate between what will brighten and what would injure the goods to be cleaned4 ,,calendering4 ,the process of calendering is resorted to for producing a fine smooth surface on calicoes and other goods1 and for rendering them sufficiently even to be printed upon 7see 8,calico-printing074 ,the calendering machine consists of a set of five rollers1 constructed to revolve at unequal rates1 so that the one which turns upon the face of the calico not only rolls it between itself and its fellow1 but--turning faster--rubs it and gives a gloss to the surface similar to the effect which would be produced if the goods were laid on a table1 and the roller rubbed over them instead of being rolled4 ,these rollers are very curiously constructed4 ,they are made by packing many hundreds of round pieces of pasteboard--having each a square hole in the centre1 and several smaller circular ones in the margin--on to a central bar of iron1 with similar bars through the smaller holes1 until a sufficient number have been added to produce the length of roller required4 ,nuts are then fitted to the ends of the smaller iron bars1 and these being screwed tightly1 compress the whole into so solid a mass1 that it can be turned in a lathe to a perfectly smooth surface1 which is 7unlike wood7 not liable to crack1 and1 being slightly elastic1 does not crush the goods1 as metal rollers would4 ,,bread ,,making4 ,this process is much the same whatever kind of meal or flour may be used1 whether wheaten1 barley1 c4 ,a certain portion of the flour is mixed with warm water 7in which a little salt is generally dissolved71 some yeast or 8barm0 7the froth from the fermentation of beer7 is added1 and the whole worked together to a pasty consistence1 this is put into a pan to keep warm1 and is called 8the sponge20 besides flour and water nearly every baker mixes his sponge with a certain proportion of potatoes boiled to a 8squash10 and passed through a sieve to separate the rinds4 ,in an hour or so it swells up to double its original size1 from the fermentation which is going on producing a kind of gas called 8carbonic acid10 which being formed in every part of the 8sponge10 inflates it to a great extent4 ,after a time it sinks down 7most of the gas escaping71 and begins to rise again2 it is then mixed with the remainder of the flour 7and some water if necessary71 and the whole thoroughly kneaded together with the hands till it is all of an equal consistence--this should be neither too stiff1 nor so soft as to stick to the hands4 ,it is now to be cut up and weighed out into pieces to form each loaf4 ,the oven in which the bread is baked is made of 8fire-brick10 and so embedded in earth or brickwork that when heated it shall not readily cool2 this is heated with coal or wood till it is nearly red-hot and the loaves are put in and left till baked4 ,,sugar ,,refining4 ,when brown or raw sugar is refined it forms the white crystalline product known as loaf sugar4 ,the process involves many ingenious arrangements in its detail1 but the essential object to be obtained is the separation of all coloring matter from the raw material without producing any more by the process1 which is a greater difficulty than would at first appear1 for all solutions of sugar evaporated in the open air become to a great extent colored1 and the longer the exposure1 and the higher the temperature1 the worse the product2 a substance forming called 8caramel10 which discolors it4 ,illustration3 ,,fig4 #a4 7 ,,conical ,,pot47 ,illustration3 ,,fig4 #b4 7 ,,filling ,,conical ,,pots47 ,the brown sugar is first mixed with a very small quantity of boiling water1 just sufficient to form a thick pasty mass1 which is put into conical pots 7figs4 #a and #b71 and allowed to drain1 the small quantity of water washes out only the brown part1 and leaves the crystals pretty white2 they are then dissolved in water1 mixed with some bone-black and bullock's blood2 the bone-black is the charcoal from burnt bones1 and has the power of taking away the color of most vegetable solutions1 the bullock's blood is used as affording a cheap kind of albumen1 which when the solution of sugar is boiled coagulates and entangles all the floating matters so that they may be removed by filtration4 ,illustration3 ,,vacuum-,,pan4 ,illustration3 ,,fig4 #c4 7 ,,sugar ,,lathe47 ,the liquid is boiled for a time1 and then put into a cistern excluded from the light1 having holes at the bottom into which long tubes of thick twilled cotton are fastened1 through which the solution runs as bright as water2 they all hang down into another cistern below1 also kept from the light1 from which it is pumped up into the evaporating apparatus--a copper vessel entirely air-tight1 heated by steam and having a powerful air-pump attached to it by which all the vapour and air are removed as the syrup becomes hot2 this is called a 8vacuum pan0 7see engraving71 and by this the syrup is condensed to the proper consistence1 and is put into moulds of the shape the loaf is to be1 having holes at the lower part which are plugged up1 the syrup as it cools forming a solid mass of crystals2 these moulds are arranged in rows over a channel leading to a proper receptacle1 the plugs are taken out from the holes at the bottom of each and some pure concentrated syrup is poured on to the upper part2 this slowly descending filters through the sugar1 carrying with it any 8caramel0 that may have formed1 finally escapes at the hole1 and runs into the cistern2 this completely whitens the sugar1 and gives it a brighter and coarser grain4 ,the loaves are then taken from the moulds1 dried in an oven at a gentle heat1 and finally packed in paper for sale4 ,if the pointed ends are discolored or ragged the loaf is put into a lathe 7fig4 #c7 and the end turned to a proper figure or cut off4 ,,brewing4 ,illustration3 ,,the ,,vats4 ,illustration3 ,,fermenting ,,room4 ,illustration3 ,,engine ,,room4 ,illustration3 ,,mash ,,tun4 ,illustration3 ,,boiler4 ,beer is made by pouring boiling water upon ground malt1 and after a time drawing it off1 which is repeated until all its soluble parts are removed and dissolved in the water2 the liquor resulting is called 8sweet wort10 which is then boiled with a certain proportion of hops 7the dried 8stobules0 or flowers of the hop plant71 and the liquor allowed to cool4 ,it is then mixed with a small quantity of 8yest10 which is the scum thrown off by a former brewing1 and the whole is allowed to ferment till nearly all the sweet sugary matter which was got from the malt is converted into spirit1 it is then put into casks and allowed to ferment slowly1 in which process it throws off more yest1 which is collected1 as seen in the cut1 for the next brewing4 ,it is then bunged up in the barrels and kept for a time1 when it is fit for use4 ,in large breweries machinery of various kinds is employed1 such as pumps for pumping up water1 taps for drawing it off machinery for stirring up the mash in the 8mash tun10 and also the hops in the boiler1 to prevent them burning at the bottom of it4 ,the 8cooling floor0 is a contrivance for cooling the wort1 consisting of a series of pipes which pass in a serpentine manner through it1 and through which cold water is made to flow4 ,the kind of beer1 whether ale or porter1 chiefly depends upon the kind of malt used2 for ale1 very pale malt1 called 8amber10 while for porter1 burnt malt is employed1 and hence the color of these two descriptions of beer4 ,if the fermentation is not carried far enough the beer will be too sweet1 and if too far it will be sour4 ,illustration3 ,,cooling ,,floor4 ,,distillation4 ,illustration3 7 ,,distillery47 ,the process of distilling consists in converting the fluid to be distilled into vapour1 and condensing it into a fluid in another vessel4 ,by this process the more volatile parts of any fluid are separated from the rest2 for example1 if brandy be distilled1 the spirit or alcohol it contains will be converted into vapour and will condense in the receiver comparatively pure 7see 8,alcohol071 leaving behind in the still the water1 coloring matter1 c41 so that the spirit is colorless1 although the brandy may have been quite brown4 ,also1 if common water be distilled1 pure water will pass over1 and the earthy matters which the water had contained will be left behind 7for all ordinary water contains considerable quantities of earthy matters1 dissolved out from the earth over which it flows74 ,the vessels used for distilling are very various in their forms1 to suit the different fluids1 both as to quantity and quality 7see 8,still074 ,there is a contrivance lately used for distilling spirit from the fermented wash containing it1 by which it is allowed to flow into an apartment full of double floors1 a few inches above each other1 the upper ones being made of thin copper perforated all over with minute holes1 and on which the wash is allowed to flow to the depth of about an inch4 ,into the space between the upper and lower parts of each floor steam is admitted1 which1 rising through the little holes1 is condensed by the wash1 giving out its heat to the spirit contained therein1 and causing it to be converted into vapour1 which passes off from the spaces between the floors to a condensing apparatus with which they all communicate4 ,,gilding4 ,gilding consists in covering the surfaces of various articles with a thin layer of gold1 and may be divided into two kinds1 quite different processes and practised by different artisans4 ,the first is 8oil-gilding10 which is a mechanical application of gold-leaf to some adhesive surface1 the second is 8water-gilding10 and is a chemical process4 ,in oil-gilding1 where frames1 c41 are to be covered with gold-leaf1 the first thing necessary is to obtain a smooth even surface on which it will lie1 but as carved frames are expensive1 ornaments of a kind of putty are fixed to the frame1 and coated with whiting and size4 ,the gold-leaf is made to adhere easily to this clammy surface1 by simply damping it1 and pressing the gold on by means of a piece of cotton wool1 afterwards gently brushing it into all the markings4 ,wood and other articles to be gilt are coated with 8gold-size10--a sort of varnish--and when this is nearly dried1 so as to be what is called 8tackey10 it will hold the gold in the same way4 ,when lettering is to be done in gold1 the painted or varnished surface is first brushed over with whiting1 which prevents the gold adhering where it is not wanted1 the writing is then executed in gold-size1 and the gold-leaf applied by pressing the book on to the surface1 and finishing off with cotton wool1 which rubs off all the superfluous gold-leaf and smooths it on the surface4 ,water-gilding 7a process1 however1 in which no water is used7 consists in covering the surface of metal with a thin coating of gold2 the best metal for water-gilding is either brass1 or a mixture of brass and copper4 ,a mixture of gold and mercury1 in the proportion of one part of gold to eight of mercury1 is made hot over a fire till they have united2 it is then put into a bag of chamois-leather1 and the superfluous mercury pressed out4 ,what remains is called an 8amalgam20 it is soft1 and of a greasy nature1 so that it can be smeared over any surface with the fingers4 ,the articles to be gilt are made perfectly clean on the surface1 and a liquid made by dissolving mercury in nitric acid 7aqua-fortis7 is brushed over them by means of a brush made of fine brass wire1 called a 8scratch-brush40 ,the mercury immediately adheres to the surface of the metal1 making it look like silver1 when this is done1 a little of the amalgam is rubbed on1 and the article evenly covered with it4 ,it is now heated in a charcoal fire till all the mercury evaporates1 and the brass is left with a coating of gold1 which is very dull but may be burnished with a steel burnisher and made bright if necessary4 ,in former times articles were inlaid with thin plates of gold1 which were placed in hollows made with a graver and melted in1 a little borax being applied between4 ,when a solution of 8chloride of gold0 is mixed with ether1 the ether takes the gold away from the solution1 and may be poured off the top charged with it4 ,this solution1 if applied to polished steel by means of a camel-hair pencil1 rapidly evaporates1 leaving a film of gold adhering to the steel1 which1 when burnished with any hard substance1 has a very elegant appearance4 ,in this way any ornamental design in gold may be produced1 but it is not very durable4 ,the gilt ornaments1 scrolls1 and mottoes on sword-blades1 c41 are sometimes done in this way4 8,gilding refined gold0 would appear a great absurdity1 but something very like it is often practised in the process called 8coloring10 used by jewellers4 ,this is however never applied to 8refined gold0 but to gold that is not quite so good in color as it should be4 ,it is boiled in a liquid containing chemical substances capable of dissolving the alloy from the surface of the article and depositing a thin coating of pure gold1 giving it the appearance of being made of better gold than it really is4 ,this is in truth a species of electro-plating1 but was in use very many years before the electro-depositing process had been discovered4 ,,silvering ,,looking-,,glasses4 ,although this process is called 8silvering10 yet no silver is used2 the substance at the back of the glass is a mixture of tin and mercury1 called an 8amalgam10--indeed1 the term 8amalgam0 applies to all mixtures of mercury with other metals4 ,the process is as follows3--,a sheet of 8tin-foil0 7tin rolled out to about the thickness of paper7 the size of the glass to be silvered is placed on a perfectly level table1 covered with cloth2 upon the tin-foil some mercury is poured1 and spread evenly and quickly over the surface with a hare's foot4 ,the plate of glass is in the meanwhile to be made perfectly clean and dry--not the slightest speck or smear must remain4 ,a sheet of tissue paper1 also clean and dry1 is laid over the surface of the mercury1 the plate of glass is placed on the paper and made to correspond with the mercurialised tin-foil beneath4 ,weights are now placed on the plate of glass to keep it firmly down1 and the sheet of paper is drawn out steadily and slowly2 as it passes over the surface of the mercury it brings away all film or dust1 and the surface being left perfectly bright1 adheres so firmly to the dry glass that it is not easily removed4 ,a great difficulty is to prevent air-bubbles from finding their way between the glass and mercury4 ,the table is now raised slightly at one end1 and the superfluous mercury allowed to drain off4 ,after a few hours the tin-foil will be found to be completely united all through with the mercury1 and will be so brittle that it can be scraped off in powder from the glass4 ,great care and practice are required to silver large plates1 but any one by a few trials may succeed perfectly with a piece of glass a few inches square4 ,glass globes are silvered inside by shaking in them a mixture of mercury and tin filings until it adheres to the surface of the glass1 which must first be made perfectly dry and warm4 ,,silver ,,plating4 ,plated goods consist of metallic articles coated with a thin plate of silver2 the metal is made of a mixture of brass and copper1 which is cast into flat slabs or ingots about an inch-and-a-half thick1 the surface on one or both sides is filed flat and smooth1 and a plate of silver of about the thirtieth part of an inch thick1 but a little smaller than the metal1 is applied smoothly to it1 the edges are covered all round with borax ground fine with water and the plates tied tightly together with wire4 ,the whole is then put into a furnace and closely watched till the silver begins to melt1 when it is at once taken out and allowed to cool2 by this mode of treatment the silver adheres so firmly to the metal that they become as one piece4 ,it is then passed between steel rollers and rolled out to the required substance1 the silver and metal both becoming thinner in about the same proportion1 so that on a plate of metal1 of whatever thickness1 the silver is somewhere about a fortieth or forty-fifth part of its thickness2 these plates of metal coated with silver are worked by stamping1 punching1 or passing between rollers the edges of which have mouldings1 curves1 c41 cut on them1 and the parts of each article when moulded are afterwards soldered together so as to form what is intended4 ,wires of various forms are plated in the same way and afterwards drawn out by means of draw-plates 7see 8,wire-drawing074 ,electro-plating has to a great extent superseded this process 7see 8,electro-plating074 ,,electro-,,plating ,,and ,,deposition ,,of ,,metals4 ,illustration3 7 ,,electro-,,plating ,,process47 ,this art has for its objects the coating of metallic articles with other metals of more value1 beauty1 or durability1 such as gold1 silver1 or copper1 by means of electricity1 and the formation 7by the same means7 of other articles by the deposition of metals1 from liquids containing them1 upon moulds or engraved surfaces capable of modelling them4 ,when the deposit forms a coating intended to be permanent1 and which adheres to the article so as to be incapable of removal1 it is called 8electro-plating10 but when a fac-simile of any surface is required1 or a cast of a mould which may be removed1 forms the object to be produced1 it is called 8electrotyping0 or 8electro-depositing40 ,illustration3 ,,fig4 #a4 7 ,,electro-,,plating ,,experiment47 ,illustration3 ,,gilding ,,rings4 ,by way of experiment1 procure two vessels1 ,a and ,b1 fig4 #a1 in one of them1 ,a1 put some dilute sulphuric acid and two plates1 one of zinc1 ,z1 the other of copper1 c1 these must not touch each other1 but may be separated about half an inch by two or three pieces of wood or cork1 and bound round with string2 each of these plates must have a piece of wire fastened by soldering to their upper parts4 ,in the vessel ,b put some solution of sulphate of copper and a small quantity of dilute sulphuric acid1 and attach another copper plate to the wire which comes from the copper plate in the acid2 this second copper plate is to be immersed in the solution of sulphate of copper1 and to the wire from the zinc plate is to be fixed the object to be coated with copper4 ,if a medallion or other object is plaster1 it should be soaked in very hot wax and then brushed over with blacklead until the surface is perfectly blackened and bright2 the wire should be bound all round the margin and soldered 7as it were7 with melted wax to the medallion1 taking care that this wax also is well coated with blacklead4 ,if the object be now immersed in the sulphate of copper solution and kept at a short distance from the plate 7it must not touch it71 a coating of copper will soon cover the surface and form a perfect cast1 which when of sufficient thickness may be removed by filing the edge all round 7if instead of the plaster cast a copper coin or other copper object be used1 the blackleading is not required1 but the surface must be first made clean and bright74 ,with the same arrangement1 but using instead of the sulphate of copper a solution made by dissolving cyanide of silver in a solution of cyanide of potassium1 a coating of silver will be deposited1 and the same of gold 7if cyanide of gold be used71 but these coatings will not adhere4 ,if it be intended that the coatings shall adhere1 to plate the article with silver or gold1 it should be first thoroughly cleaned1 then brushed over with a solution of nitrate of mercury1 washed in clean water1 and put into the gold or silver solution2 the nitrate of mercury will cover the copper article with a thin coating of mercury1 which will be taken up as the gold or silver is deposited1 and this coating will adhere1 the article being thus 8electro plated40 ,as in using the solution of sulphate of copper1 a copper plate was immersed in the solution and united by the wire to the copper plate in the vessel ,a1 so in using the solution of cyanide of silver1 a silver plate must be used1 and in the gold solution a gold plate1 these plates being dissolved as the metal is deposited1 the liquid remaining pretty much the same and serving for future operations4 ,the gold and silver thus deposited are dull1 but may be burnished with a steel burnisher1 all over or in parts as the design may require4 ,in manufacturing1 these processes are much modified1 and powerful galvanic batteries or electro-magnets used2 in the latter case the electro-magnetic machine is often driven by a steam-engine and the troughs of depositing liquids contain often many dozens of articles1 which are all receiving a coating at once4 ,,soldering ,,and ,,brazing4 ,the art of uniting metals by another metal or alloy1 is called soldering 7which includes 8hard and soft soldering10 and 8brazing074 ,if any metal be applied in a melted state to the surface of a piece of cold metal1 under ordinary circumstances it will not adhere1 but runs off in globules1 this is owing to the surface being covered with 8oxide0 or rust1 but if the surface be scraped or filed bright and some substance applied which will defend it from the air1 and at the same time become fluid at the heat of the melted metal1 then it will adhere4 ,for this purpose borax is used in hard soldering and brazing1 that is in soldering with metals which require a considerable amount of heat to melt them2 and sal ammoniac1 rosin1 oil1 c41 in cases of soldering with 8soft solder10 or solder that will readily melt4 ,this soft solder is made of a mixture of lead and tin1 and if required to melt very easily 7as in soldering pewter71 then some 8bismuth0 is added4 ,bismuth itself does not melt more readily than lead1 but it has the property of causing other metals to melt more readily4 ,if the edges of two pieces of tin1 for example1 have to be soldered together1 an iron with a wooden handle and a piece of copper joined to the other end is used4 ,this is made red-hot1 and the pieces of tin being placed smoothly together and their edges sprinkled with rosin or sal ammoniac1 the hot iron 7first touched on a piece of rosin to clean it7 is then applied to the joint1 a piece of soft solder being applied at the same time1 and as this melts it is drawn in a melted state by means of the hot iron 7to which it adheres7 down the joint4 ,an excellent substance for soldering3 all sorts of small work1 such as pieces of brass1 copper1 or tin1 is chloride of zinc-this may easily be made by putting pieces of zinc into spirit of salt1 7hydrochloric acid71 and allowing them to remain as long as any effervescence continues2 this solution may be kept in a bottle and applied to any edge to be soldered1 by means of a small brush or feather4 ,when iron and copper have to be 8brazed10 the joints are made bright1 and then coated with borax ground into a paste with water4 ,a mixture of brass and zinc 7called spelter7 in small grains is sprinkled on the joint and it is then put into the hollow of a bright fire which is urged by bellows till the spelter melts4 ,silver is joined by hard or 8silver0 solder1 which is a mixture of silver1 zinc1 and copper1 and the fusion is generally effected by a blow-pipe1 7see 8,blow-pipe072 gold is soldered by a mixture of gold and copper4 ,leaden pipes are joined by having the ends to be united scraped bright and introduced a short way one within the other1 some melted solder is then poured from a small iron ladle on the joint at the same time that it is rubbed round with a piece of folded cloth greased on the surface4 ,joints in cisterns1 etc41 are generally made by scraping the edges clean with a steel scraper1 and applying some lamp-black and size by means of a brush to the parts beyond1 leaving a bright space of an inch or so on each side of the joint1 a ladle of melted solder is then gradually poured on the joint and rubbed down with a piece of greased cloth1 the lamp-black and size preventing the solder adhering to any part but that left bright1 and in this way a straight neat joint is produced4 ,,the ,,smelting ,,of ,,metals4 ,all metals are got from the earth where they exist in the form of 8ores0 7in reality metals combined with other matters71 and 8smelting0 is the process of getting rid of these other matters1 the chief of which are sulphur and oxygen4 ,the ores when dug from the mine are generally stamped into powder1 then 8roasted10 that is1 made hot and kept so for some time to drive off water1 sulphur1 or arsenic1 which would prevent the 8fluxes0 acting properly4 ,the fluxes are substances which will mix with1 melt1 and separate the matters to be got rid of1 the chief being charcoal1 coke1 and limestone4 ,the ore is then mixed with the flux and the whole raised to a great heat2 as the metal is separated it melts1 runs to the bottom of the 8smelting furnace0 and is drawn off into moulds made of sand2 it is thus cast into short thick bars called 8pigs10 so we hear of pig-iron1 pig-lead1 c4 ,iron is smelted from 8ironstone10 which is mixed with coke and limestone4 ,the heat required to smelt iron is so very great1 that a steam-engine is now always employed to blow the furnace 7before the invention of the steam-engine1 water-mills were used for the same purpose74 ,the smelting is conducted in what is called a blast furnace4 ,when the metal has all been 8reduced0 or smelted1 and run down to the bottom of the furnace1 a hole is made1 out of which it runs into the moulds2 this is called 8tapping the furnace40 ,smelting is often confounded with melting1 as the names are somewhat alike1 but the processes are entirely different2 in melting1 the metal is simply liquified1 in smelting the metal has to be produced from ores which often have no appearance of containing any1 as in the case of iron-stone1 which looks like brown clay4 ,by way of experiment let the reader take a small portion of 8litharge10 which is a reddish powder1 mix it with a drop of oil into a thick paste and place it on the end of a flat piece of charcoal or wood1 and direct the flame of a candle upon it by means of a blow-pipe2 a slight hissing noise will be heard1 and in a moment or two a small1 bright globule of lead will make its appearance4 ,,founding4 ,illustration3 ,,general ,,foundry1 ,,woolwich ,,arsenal4 ,founding is the art of casting metals into various forms by means of moulds4 ,the products of smelting are of a coarse kind1 and have to be remelted before the process of casting or founding begins4 ,before any article can be cast in metal1 a pattern must be formed in wood1 clay1 or other suitable substance4 ,the floor of the foundry is made up of sand and powdered charcoal to the depth of several feet1 serving to imbed the moulds which are used1 and in several places deep pits full of the same material are formed for large castings2 an iron frame1 corresponding to another like it1 and capable of being united to it by pins and sockets1 is used to contain the moulding sand and pattern4 ,illustration3 ,,gun ,,foundry1 ,,woolwich ,,arsenal4 ,let it be supposed1 for simplicity1 that a cannon ball has to be cast1 one of the frames is filled with moulding sand moist enough to bear a good impression1 and a cannon ball pressed half-way in2 the surface is now dusted over with red ochre 7to keep the upper half from sticking to it71 and the other frame applied and united with the lower one1 this is now filled with the sand and beaten or trodden down firmly4 ,on separating the two and removing the pattern1 there is an impression of half a ball in each half of the mould1 and when these are again put together there is a hollow corresponding to the pattern used4 ,there are1 however1 two things more to be attended to1 one is to have an opening for the melted metal to be poured in1 the other an opening for the air to escape1 and this is effected by attaching to the pattern two pieces of wood or iron which project upwards through the upper half of the mould1 and when this is carefully lifted up two holes appear which on being united to the lower half lead into the round hollow4 ,when the moulds are ready they are put into a room heated by means of stoves1 and thoroughly dried4 ,they are then buried in the floor of the foundry1 leaving the holes for pouring the metal exposed1 channels being formed in the sand1 so that when the furnace is 8tapped0 the melted metal may flow down these and fill the moulds4 ,some forms are so complicated that the moulds have to be made in several pieces1 and the ingenuity of the founder is taxed to the utmost to produce those required4 ,,glass ,,blowing ,,and ,,casting4 ,illustration3 ,,casting ,,plate ,,glass4 ,illustration3 ,,fig4 #a4 7 ,,collecting ,,glass ,,with ,a ,,puntil47 ,illustration3 ,,fig4 #b4 7 ,,blowing ,,on ,,the ,,puntil47 ,illustration3 ,,fig4 #c4 7 ,,beginning ,,glass ,,form47 ,illustration3 ,,fig4 #d4 7 ,,glass ,,globe ,,with ,,hole ,,at ,,end47 ,glass-blowing requires great practice and manual dexterity1 for the material used being red-hot cannot be touched with the hands1 and has to be very rapidly worked1 or it becomes cooled and hard2 to any one unused to work with it1 it is the most unmanageable material conceivable1 but by practice the glass-blower contrives to produce almost any form required1 and of a size quite astonishing--as1 for instance1 the globular bottles seen in druggists' windows1 which often hold twelve gallons1 also glass shades1 which are of an uniform thickness1 and two or three feet high4 ,this is all done by means of a hollow rod of iron called a 8puntil10 on the one end of which a mass of molten glass is collected 7fig4 #a71 and the workman blows into the other1 at the same time turning the tube rapidly round in his hands 7fig4 #b74 ,when the kind of glass called 8crown-glass0 has to be made1 the end of the iron tube is put into the pot of melted glass1 and turned round till a ball of it is collected about the size of one's head1 the workman then blows in at the other end1 still turning the rod in his hands2 it has now the appearance presented at fig4 #c4 ,an iron rod is stuck on to the side of the globe opposite to the 8puntil10 which is then pulled suddenly away1 leaving a round hole4 ,the globe of glass is again made red-hot1 and spun round rapidly1 the hole increasing in size until it resembles fig4 #d4 ,by continuing the rapid twirling of the rod1 the hole opens wider and wider till at last one broad sheet is produced2 it is then separated from the rod by putting a drop of cold water at its junction with the glass1 which causes it to crack across at that part4 ,it is now about six feet in diameter1 perfectly round and flat1 and when cold it is cut into halves and packed with straw in a 8crate0 for carriage4 ,the knot of glass often seen in kitchen or stable windows1 is the part in the centre of the glass where the iron rod has joined it1 and is called the 8punty40 ,illustration3 ,,fig4 #e4 7 ,,elongated ,,blow ,,glass47 ,sheet-glass is commenced in the same way as crown1 but instead of a hole being made the blowing is continued till a great round ball is formed1 the rod and this ball are then swung round at arm's length--a hole being sunk in the ground for the purpose--which causes the globe to become elongated1 as in fig4 #e4 ,it is then laid upon an iron table1 and rapidly slit up1 the compressed air escaping from within opening it out into a broad sheet1 which is instantly cut square while yet soft4 ,illustration3 ,,plate ,,glass ,,casting4 ,,bringing ,,out ,,the ,,pot4 ,illustration3 ,,fig4 #f4 7 ,,grinding ,,the ,,plate ,,glass47 ,plate glass is cast by pouring it from a large pot on to a flat iron table with a ridge all round it1 and on which an iron roller is so placed that when the molten glass flows on the table it passes over and flattens it out to the required thinness1 which is regulated by elevating or depressing the ridges at the sides of the table1 made moveable for that purpose 7the process is illustrated by the cut at the head of this article74 ,when cold1 the surface of the plate is ground perfectly flat and even by means of emery-powder 7fig4 #f71 and then polished with a cloth rubber charged with a fine red oxide of iron called 8crocus0 7fig4 #g74 ,the grinding and polishing are both performed by steam machinery4 ,illustration3 ,,fig4 #g4 7 ,,polishing ,,the ,,plate ,,glass47 ,illustration3 ,,fig4 #h4 7 ,,blowing ,,glass ,,into ,,form47 ,bottles1 and such like articles are either simply blown into the form required1 or into moulds made to close upon the ball of soft glass1 and again open when the required form has been given 7fig4 #h74 ,many articles of glass are cast1 or 8struck-up0 by compression in a mould1 and are often made to resemble cut-glass articles1 but they are much inferior in appearance4 ,the best articles of glass are first blown1 and afterwards cut and polished 7see 8,glass-cutting074 ,of whatever kind the article of glass may be1 it is so brittle that the slightest blow would break it1 a bad quality which is got rid of by a process called 8annealing40 ,this consists in placing it while quite hot on the floor of an oven1 which is allowed to cool very gradually indeed4 ,this slow cooling takes off the brittleness2 and articles of glass well annealed1 will scarcely break with boiling water1 and are very much tougher than others4 ,,glass-,,cutting4 ,illustration3 ,,glass-,,cutting4 ,the kind of glass generally used for ornamental cutting is flint-glass4 ,decanters1 wine-glasses1 c41 are also made of it2 it is very bright1 white1 and easily cut4 ,glass is cut by means of wheels of different sizes and materials1 turned by a treadle1 as in a common lathe2 some are made of fine sandstone1 some of iron1 others of tin or copper2 the edges of some are square1 some round1 and some are sharp4 ,they are used with sand and water1 or emery and water1 but stone wheels are used with water only4 ,the glass-cutter also uses rods of copper with knobs at their ends1 for making round indentations2 these turn on their axis1 so that the end cuts a round hollow in the glass4 ,the work is at first cut roughly1 afterwards smoothed off with the sandstone or tin wheel 7the latter has to be smeared with emery and water71 and finally polished by a wooden wheel with finely-powdered pumice-stone applied to its edge1 and moistened with water4 ,the glasses for spectacles and optical instruments are cut by concave or convex moulds of brass moistened with emery and water1 and polished by means of a mould of pitch wetted with crocus and water4 ,great art and accuracy are required to grind the glasses for optical instruments1 especially very large or very small ones1 as for microscopes1 the various 8powers0 of which constitute their chief expense--one of the sixteenth of an inch in diameter costing about twelve pounds4 ,,bricklaying4 ,illustration3 ,,bricklaying4 ,illustration3 ,,fig4 #a4 7 ,,unstable ,,stacking ,,of ,,bricks47 ,illustration3 ,,fig4 #b4 7 ,,english ,,bond47 ,illustration3 ,,fig4 #c4 7 ,,flemish ,,bond47 ,illustration3 ,,fig4 #d4 7 ,,plumb47 ,illustration3 ,,fig4 #e4 7 ,,trowel47 ,illustration3 ,,fig4 #f4 7 ,,hod47 ,nearly all houses are built of bricks1 as they are less expensive than stone1 and more durable than wood1 besides being less liable to be burnt4 ,walls of brick may be formed of any required thickness1 and as the length of a brick is twice its breadth1 they admit of being so laid that the wall shall not part in pieces1 which would be the case if laid as in fig4 #a1 as the seams of mortar run continuously through the wall1 which in bricklaying is always avoided1 by different methods4 ,formerly bricks were laid in what was called 8,english bond0 7fig4 #b71 but this is not now used1 8,flemish bond0 7fig4 #c7 having superseded it4 ,the mortar with which bricks are laid is made of lime and sand1 mixed with water to a convenient consistence2 it sets quickly1 hardens with age1 and resists the action of rain and time4 ,the ordinary mode of laying bricks is to stretch a line from end to end of the course on which they are to be laid2 the surface of the under course is spread for a short distance with mortar1 and the bricks intended to form the outer surface of the wall are laid first1 in an exact line with the cord1 the 8plumb0 7fig4 #d7 being frequently used to ascertain if they are perpendicular4 ,the 8plumb0 is a piece of board with a notch at the centre of the top1 and a hole1 also in the centre1 near the bottom2 a piece of cord is passed through the notch1 with a leaden ball attached1 which swings in the hole as the plumb is placed at the side of the wall4 ,the ball of lead just falls in the hole if the wall is upright1 and in this way a wall may be built to any height1 exactly perpendicular4 ,the corner of brickwork where windows occur1 is called the 8arris10 and has to be made upright both in front and at the side4 ,when very thick walls are to be made 7as in railway cuttings71 the outer surface and back of the walls are laid in the usual way1 the space between is filled with a layer of bricks1 and thin liquid mortar is poured on and scraped about with a sort of hoe till the spaces between the bricks are all filled up and the surface left level1 when another course is laid in the same manner4 ,fig4 #e is a trowel1 or instrument used to take up and spread out the mortar1 and fig4 #f is the hod1 in which the labourer carries supplies of bricks or mortar to the spot where the bricklayer is working4 ,,stone ,,cutting4 ,illustration3 ,,stone-,,cutting4 ,illustration3 ,,fig4 #a4 7 ,,iron ,,pick47 ,illustration3 ,,fig4 #b4 7 ,,chisel ,,and ,,scraper47 ,some stones1 as 8,bath stone0 can be cut with a common toothed saw1 and are but little harder than chalk2 others1 as marble1 ,portland stone1 c41 require to be cut with a flat blade of iron stretched in a frame and having a supply of sand and water4 ,a man sits in a shed having this heavy saw suspended from two poles1 and balanced by a piece of stone swung over a pulley2 he alternately pushes and pulls the frame1 allowing the water to trickle into the seam as it forms1 the sand being rubbed between the edge of the saw and the stone as the saw is moved backwards and forwards1 slowly cutting the stone 7see illustration74 ,by this slow and tedious process building stones are cut into squares1 slices1 slabs1 or any other form required4 ,granite is too hard for even this slow process1 and after the pieces are chosen as nearly as can be got of the size and shape required1 they are worked with a heavy iron pick 7fig4 #a71 which at each blow strikes off a little piece not bigger than a pea1 by which method the stone is shaped into the form required4 ,smaller cuttings of stone for building purposes1 such as carvings1 c41 are formed by the mallet and chisel 7fig4 #b71 the work being finished with a rasp or steel scraper4 ,,apparatus ,,and ,,machinery4 ,,steam-,,engines4 ,illustration3 ,,beam ,,of ,,steam ,,engine1 ,,woolwich ,,arsenal4 ,the great improvements in machinery--whether for looms1 locomotive engines1 or steam-ships1 for forging anchors1 boring cannon1 rolling out and rivetting iron plates together for tubular bridges and boilers1 or any other kind of work--are chiefly owing to the wonderful ease with which these machines can be driven by the power of steam4 ,it matters not whether the object to be wrought is the head of a pin1 or the crank of a steam-ship1 it is done with both delicacy of touch and power of arm1 a hundredfold beyond what could be effected by hand in the same time4 ,the motive power of steam is derived from the property which water has of being expanded into vapour when heated to a certain degree1 and of again resuming the form of water when cooled2 this moreover takes place in the most easily manageable manner1 and either by degrees or suddenly1 according as the heat and pressure balance each other2 moreover water1 being easily obtained1 and in sufficient quantity for the purpose1 in all places where machinery is required1 can always be applied4 ,before the use of steam1 wind1 water1 horse1 and hand power were chiefly in use2 water-mills were1 of course1 only erected in those situations where a good supply of water could be obtained1 and this even often failed in dry weather2 windmills also depended on that uncertain element4 ,horse and hand powers are limited in their extent1 and are moreover very expensive4 ,the first attempts at a steam-engine were those in which the steam was only used that by its condensation a vacuum might be formed in a cylinder under a piston1 so that the weight of the air should cause this to descend with considerable force--#ae lbs4 on the square inch4 ,the piston was balanced by a weight1 so that the steam might raise it with scarcely any pressure2 the steam beneath the piston being condensed by a stream of cold water1 the weight of the air again forced down the piston into the vacuum4 ,this therefore was not a steam but an air-engine1 as all the power exerted was derived from the weight of the air1 and the steam merely used to procure a vacuum4 ,after this came the low-pressure or condensing engine1 and then the high-pressure or non-condensing engine1 both of which are now used1 the former in marine engines and the latter in locomotives4 ,illustration3 ,,fly-,,wheel1 ,,woolwich ,,arsenal4 ,illustration3 ,,fig4 #a4 ,,boilers1 ,,woolwich ,,arsenal4 ,illustration3 ,,fig4 #b4 ,,boilers1 ,,woolwich ,,arsenal4 ,the steam-engine consists essentially of a boiler or steam-generator1 with a furnace adapted to it1 connected by a steam-pipe to a cylinder having a piston working accurately in it1 and valves so contrived that the steam shall enter alternately above and below the piston4 ,in the condensing engine1 each compartment1 above and below the piston1 communicates with the condenser--the vessel in which the steam is suddenly condensed by cold water--and the valves are so arranged that when the steam enters above the piston1 the space below is opened to the condenser1 and is therefore a partial vacuum2 by the time the piston is driven down by the force of the steam above it1 the space is shut off from the condenser and opened to the steam-pipe1 while the space above is shut off from the steam-pipe and opened to the condenser4 ,in this way one side of the piston is alternately pressed by the steam while there is a vacuum on the other side4 ,in the non-condensing engine the space above and below the piston is alternately pressed by steam at a great degree of tension2 while at the opposite side of the piston1 the space is opened to the air by a valve4 ,these valves are what are called 8sliding valves10 being both in connection with the same action1 which shuts one while it opens the other2 that is1 when the piston has nearly descended1 it slides the valve which shuts off the steam from the space above and opens it to the air1 the same action opening the steam-valve below the piston and shutting it from the air4 ,in this kind of engine the piston is moved simply by the power of the steam1 which first presses it down and then presses it up again1 and as the steam escapes at each stroke of the piston1 and has to be at a great tension or pressure1 a large and rapidly-formed supply of steam is required4 ,in the locomotive and other high-pressure engines this is effected by having a great number of tubes passing through the boiler leading from the fire-place to the flue1 so that the fire and heated air shall pass through them before reaching the flue1 and consequently1 as these all pass through the water in the boiler1 producing a very rapid generation of steam4 ,of the various forms of boilers1 the most simple was that in which the heat was merely applied to the lower part 7fig4 #a72 next may be named the wagon-head boiler1 in which the flue passed all round2 some were made with a cylindrical flue passing though the whole length1 and some with two 7fig4 #b74 ,of whatever form the boiler may be1 it should be strong enough to well resist the pressure of the steam1 but to make this sure1 a contrivance called a safety-valve is always used2 this consists of a valve held down by a weight1 which would be raised by the steam if it should press so hard as to endanger the boiler in the least degree2 when the safety-valve is forced up1 the steam escapes and the pressure is taken off4 ,most steam engines require the up-and-down motion of the piston to be converted into a circular motion1 and this is effected by means of a 8crank10 7see 8,cranks072 but this circular motion needs in most cases to be regulated by a fly-wheel which is so heavy1 that upon being set in motion it continues to revolve for a time by its own weight1 so that the intermitting pulls exerted by the piston-rod on the crank are blended into one continuous action 7see cut72 but in steam-ships1 and locomotive engines1 fly-wheels cannot be used4 ,in these cases there are two cylinders and pistons1 each fixed to a crank formed in one axle united to the two wheels1 and these cranks are so arranged that the greatest power is exerted on one when the least is exerted on the other1 and for this purpose they are placed so that when one crank is upright the other is horizontal4 ,the stroke of the piston-rod is not always made to act directly on the crank1 but has a 8beam0 interposed working on bearings in its centre1 hence the term beam-engine 7see cut74 ,this beam moves the crank at the opposite end to that which is moved by the piston and at the same time works the air-pump1 feed-pump1 and cold-water-pump1 by means of jointed rods4 ,illustration3 ,,fig4 #c4 7 ,,governor47 ,in those engines which have to perform unequal work1 and in which sometimes a great drag is suddenly removed from the engine1 some contrivance is necessary to prevent the too rapid motion which would ensue1 to the great risk of damaging the engine2 this is effected by what is called the 8governor20 a contrivance by which a part of the steam is struck off when the action is too rapid1 and again let on when it has diminished4 ,this arrangement is shown in fig4 #c2 the two heavy iron balls swing round as the engine works1 and the faster they revolve the more they tend to separate1 from the natural tendency to fly off called 8centrifugal force10 and in separating they bring the other ends of the rods to which they are attached nearer together1 and so push up a collar1 ,a1 attached to the levers which turn off the steam-tap2 and as the action subsides the balls sink down together and the collar also1 the steam being thus turned on again4 ,in order that the pressure of the steam in the boiler may be known1 a 8gauge0 is used1 which acts on the principle of the barometer1 consisting of a column of mercury which is pressed up by the force of the steam1 the height to which it rises indicating the pressure4 ,with respect to the details of the steam-engine1 they are too various and complicated to be enumerated or described here2 but the motion--being regular1 continuous1 and powerful--can be applied to almost any sort of work by being adapted to the machine suitable for such work1 and which receives its motion from the steam-engine1 the same as though it were worked by water or by hand4 ,,boilers4 ,boilers are vessels in which fluids are boiled or heated1 and are almost of every form and size4 ,some boilers1 such as those attached to steam-engines1 are more strictly called 8steam generators10 as they are constructed solely for the production of steam at the lowest possible expense of time and fuel1 and also to resist the pressure which the steam exerts at high temperatures2 these boilers are not only used to produce the steam for the motion of engines1 but are extensively used in its production for heating evaporating-pans and boilers 7in the strict sense of the word71 and also for warming and ventilating buildings4 ,they are more particularly noticed under the head 8,steam ,engines40 ,boilers for all purposes were formerly made of metal 7usually copper or iron71 and were exposed directly to the fire intended to heat their contents1 but since the properties of steam have been more fully recognised1 it is now very frequently employed for heating boilers--especially where a heat at or below the boiling point of water is required4 ,there are great advantages arising from this plan1 one of which consists in doing away with the risk of the materials in the boiler being burnt4 ,some boilers are now made of wood1 having steam-pipes running through them1 and in those cases in which the admixture of water is no detriment steam--in the form of jets--is thrown directly into the fluid to be heated1 which very quickly raises it to the boiling point4 ,boilers of cast-iron1 lined with platinum or enamel1 are also used for various purposes1 as the condensation of acid substances1 c41 which would act on most metals4 ,glass and glazed pans1 too1 can be used with a steam apparatus1 without any danger arising from breakage1 which would frequently occur if they were directly applied to the fire4 ,,furnaces4 ,illustration3 ,,fig4 #a4 7 ,,reverberatory ,,furnace47 ,illustration3 ,,fig4 #b4 7 ,,blast ,,furnace47 ,illustration3 ,,fig4 #c4 7 ,,cutaway ,,diagram ,,of ,,blast ,,furnace47 ,furnaces are fire-places constructed to serve particular purposes1 and are chiefly of two kinds1 8,wind furnaces0 and 8,blast furnaces40 ,of the first kind the common house grate is an instance1 of the second the blacksmith's forge4 ,the fire in a wind furnace is more or less shut up1 so that the draught of air entering it shall pass from the ash-pit right up into the fire1 and through it into the flue or chimney--the latter being tall1 and of certain proportions1 so as to ensure the requisite draught4 ,these furnaces are used where heat of the very highest degree is not required1 as in glass-houses1 pottery-kilns1 c4 ,the 8,reverberatory furnace0 is a modification of the wind furnace1 and is used to throw heat on to the surface of substances1 as in roasting ores of metals1 to drive off the sulphur1 arsenic1 c41 or in the making of soda1 litharge1 and other processes where the admission of hot air with the flame is either beneficial1 or at least not detrimental2 fig4 #a shows the construction of this kind of furnace4 ,blast furnaces are for the production of the very highest degrees of temperature1 and in these the air is forced into the fire by blowing machines or bellows1 often worked by steam-engines2 such furnaces are used for the smelting and casting of iron1 c4 7fig4 #b74 ,a good blast furnace for small purposes may be made by two crucibles--those made of coarse blacklead and clay1 and called 8,blue pots10 are the best--one placed inside the other1 the outer one having a hole at the lower part for the nose of the bellows1 the inner one having the bottom cut off and a grating of iron put in to lodge just above the lowest part2 the space between the two should be filled with powdered fire-brick or broken-up crucibles 7fig4 #c74 ,,bellows ,,and ,,blowing ,,machines4 ,illustration3 ,,fig4 #a4 7 ,,blacksmith ,,bellow47 ,illustration3 ,,fig4 #b4 7 ,,double-,,bellow47 ,illustration3 ,,fig4 #c4 7 ,,fan ,,wheel47 ,illustration3 ,,fig4 #d4 7 ,,fan ,,wheel ,,housing47 ,the common bellows is the most familiar form of blowing machine4 ,it consists of two boards bound together with leather1 having folds so arranged that the upper board may be raised or depressed1 and the whole is made air-tight2 in the lower board is a hole with a leather flap-valve opening inwards4 ,when the upper board is raised1 the air rushes in at the hole1 pushing up the valve1 and when the board is lowered the air presses the valve down1 and so shuts it close1 it has therefore no exit but at the nose of the bellows1 from which it passes out4 ,blacksmiths' bellows 7fig4 #a7 are made double1 for the purpose of keeping up a continuous stream of air1 instead of the separate puffs produced by the common single bellows4 ,the arrangement of the double bellows is as follows3--,there are three boards bound together with leather folded as in the common house bellows2 the board in the middle is fixed1 and to this the nose is fastened1 but it opens only into the space above2 the upper and lower boards are united to the middle one by a hinge1 and are capable of being moved up and down2 the middle and lower ones have each holes and valves opening upwards as in the common bellows1 and when the lower board is raised it presses the air in the space between it and the middle board through the hole in the latter1 into the space between it and the upper one1 and so raises it2 this has a heavy iron weight placed on it which makes it sink down and force the air out through the nose4 ,while this weight is sinking the lower board is pushed down1 and is ready to force a fresh quantity of air into the upper space1 so that one continuous stream of air issues at the nose of the bellows4 ,the handle is fixed to the lower board1 and generally has a cord uniting it to a wooden handle1 which is worked like a pump-handle 7fig4 #b74 ,for large furnaces1 blowing machines of various kinds are used1 generally consisting of a pair of large cylinders having pistons worked in them by steam power1 and pumping air into a large air-chamber1 from which it proceeds in three or four pipes to the furnace1 or sometimes to numerous furnaces1 each having a tube and stop-cock by which the 8blast0 may be turned on1 similarly to gas or water1 the air-chamber being always kept filled at a great pressure by the cylinders1 and furnished with a safety-valve to prevent the pressure bursting it4 ,there is another kind of blowing-machine1 consisting of a fan wheel turning very rapidly in a round box 7figs4 #c and #d71 from which a tube proceeds1 and having holes in the sides to admit the air1 which is thrown forwards by the fans of the wheel4 ,,screw ,,propellers4 ,illustration3 ,,screw ,,steam-,,vessel4 ,illustration3 ,,fig4 #a4 ,,screw ,,steam-,,vessel1 ,,showing ,,the ,,fan4 ,illustration3 ,,fig4 #b4 7 ,,propeller47 ,these are instruments placed at the back part of steam-vessels for the purpose of propelling them through the water4 ,fig4 #a will show the position they occupy1 and fig4 #b the shape of the propeller4 ,when first used1 they had one or two entire turns round the axis1 but are now made with two blades1 each forming about one-sixth part only of one turn1 and this is found to give more power with less friction4 ,the propeller is turned rapidly round in the water1 from which it meets with resistance in a direction perpendicular to the surface of its blades1 but as this is oblique to the direction of rotation the force is exerted in two directions1 one directly opposes this rotation1 and is overcome by the power of the steam-engine1 the other is in a direction towards the ship1 overcoming the inertia of the vessel and the friction and resistance of the water1 so that the ship is moved along1 and the propeller winds its way through the water in a spiral direction as an ordinary screw does through the hollow screw made to fit it1 the vessel travelling at a speed proportionate to the screw's revolutions4 ,,anchors4 ,illustration3 ,,fig4 #a4 7 ,,anchor ,,with ,,wood ,,stock47 ,illustration3 ,,fig4 #b4 7 ,,anchor ,,with ,,iron ,,stock47 ,illustration3 ,,fig4 #c4 7 ,,space-,,saving ,,anchor47 ,illustration3 ,,fig4 #d4 7 ,,anchor ,,at ,,rest47 ,illustration3 ,,fig4 #e4 7 8,,weighing0 ,,anchor47 ,these ponderous instruments are used for the purpose of securing ships and other vessels1 that they may not be driven onwards by the wind or tide4 ,they are attached to a strong rope or chain1 called the 8cable10 and when not in use are kept swung at the fore-part or bow of a ship1 the cable being wound round an apparatus called the capstan1 which serves to let it out or draw it in4 ,anchors are made of iron1 and are of the form delineated in fig4 #a4 ,the straight part from the ring to the bend is called the 8shank10 the curved part is made up of the two 8arms10 and the centre where it joins the shank is called the 8crown40 ,at the end of each arm is a plate of iron of triangular form1 called a 8fluke10 and crossing the shank close to the ring is the 8stock10 which is made of two pieces of oak bound together with iron bands2 sometimes it is made wholly of iron1 as in fig4 #b1 in which case it runs through a hole in the shank1 and has one of its ends curved for the purpose of packing more closely and saving space 7fig4 #c74 ,the anchor1 when let fall from the ship1 carries the cable with it1 and generally falls on the crown1 then tilts over so that the stock lies flat on the bottom and one of the flukes sinks in to a considerable depth by its great weight2 when the ship drags at the cable it lifts up the stock and throws the whole weight of the anchor on the fluke1 and makes it sink completely2 any further pull must bring up a large piece of the earth before it can be moved4 ,in 8weighing0 anchor1 that is in pulling it up from the bottom to bring it on board again1 the cable is slowly wound up by the capstan1 and as the cable is shortened the ship is drawn along to a point nearly over where the anchor rests1 when--the pull at the cable continuing--the shank is raised into an upright position1 and the fluke and arm1 instead of dragging up a great piece of earth1 remove but a small portion1 as may be seen by the dotted lines in figs4 #d and #e1 which show the earth to be removed before the anchor can be drawn from its hold4 ,large vessels carry four anchors1 the 8best bower10 the 8small bower10 the 8sheet10 and the 8spare0 anchors1 their size depending on the size of the ship1 the rule in the ,royal ,navy being a hundred-weight for each gun2 so that an eighty-gun ship carries anchors of four tons each1 or eighty hundredweight4 ,anchors are made of the best and toughest wrought iron1 and the greatest care is necessary in forging them in order that there may be no flaw in the welding1 for a ship may be lost by an anchor breaking4 ,,chains4 ,illustration3 ,,fig4 #a4 7 ,,link ,,chain47 ,illustration3 ,,fig4 #b4 7 ,,wheel ,,chain47 ,illustration3 ,,fig4 #c4 7 ,,chain ,,with ,,stay47 ,illustration3 ,,fig4 #d4 7 ,,chain ,,with ,,extended ,,stay47 ,chains are made up of separate links of rigid metal which having no flexibility in themselves are yet so united that each shall move freely on the next links to it1 and thus produce a flexible whole4 ,for ornamental purposes there is almost an endless variety of patterns1 as may be seen in jewellery-work--but for the purposes of business and machinery there are chiefly but two1 the ordinary1 as fig4 #a1 and that which will only bend in one plane1 as in fig4 #b--this is chiefly made use of in passing round wheels1 as in clocks4 ,chains are used where rough wear is required1 in which case rope would be rapidly worn through4 ,cables of chain are now much more generally used than hempen ones1 as they are more to be depended on1 take up less room1 and are not so liable to be cut or worn by rough rocks at the bottom4 ,in chain cables a 8stay0 is placed in every link 7fig4 #c71 which greatly increases its strength1 but the best form of chain cable is shown at fig4 #d2 in this the links are somewhat angular1 and the stays longer4 ,chains are chiefly made by machinery2 the rods are first drawn out of the proper size1 pieces of the required length are then cut off and bent to the right form1 and the stay and this link are then both made white hot1 placed in their right position1 and welded together by pressure4 ,,cranes4 ,illustration3 7 ,,yard ,,crane47 ,illustration3 ,,fig4 #a4 7 ,,wheel ,,assembly47 ,illustration3 ,,fig4 #b4 7 ,,floor ,,crane47 ,illustration3 ,,fig4 #c4 7 ,,landing ,,crane47 ,illustration3 ,,fig4 #d4 7 ,,landing ,,crane47 ,illustration3 ,,fig4 #e4 7 ,,jib ,,crane47 ,illustration3 ,,fig4 #f4 7 ,,swing ,,crane47 ,these machines are used for raising heavy bodies in a perpendicular direction4 ,they are of various forms suitable for almost every purpose1 and to most of them are adapted two or more wheels with teeth1 one small and one large1 for the purpose of obtaining power at the expense of time 7fig4 #a72 the small wheel is turned by a windlass1 and turns the larger one very slowly but with great power4 ,the common warehouse or cellar crane is generally an iron frame with two pulleys1 and the arrangement shown at fig4 #a4 which is usually inside the warehouse1 while the crane is outside to raise goods from carts1 c41 into the floors above 7fig4 #b74 ,cranes at the sides of canals or rivers for landing goods are sometimes made as figs4 #c and #d2 in the last there is a heavy stone placed to balance the weight at the end of the crane4 ,what is called the 8jib crane0 is often 8rigged0 up on shipboard for shipping and unshipping goods 7fig4 #e74 ,cranes for very heavy purposes have been made upon the tubular principle and consist of iron plates rivetted together so as to form a hollow curved crane1 similar to the hollow girders used in bridges4 ,where goods have to be brought from one particular spot to another1 as in fig4 #f1 the swing crane is used4 ,amongst cranes may be named the hydraulic lift2 this is exactly similar to the hydraulic press1 only applied in a different manner1 and is used to lift very heavy weights but short distances1 as for raising heavy goods on to railway trucks1 c4 ,,cranks4 ,illustration3 7 ,,knife-,,grinder47 ,illustration3 7 ,,piston ,,crank47 ,cranks are bends in the axle of any part of a machine by which an up-and-down motion is converted into a circular or rotatory one1 as in the common knife grinder's machine2 in this arrangement a fly-wheel is necessary to continue by its momentum 7tendency to go on7 the motion begun by the upward and downward action of the treadle1 piston-rod1 c41 as the case may be4 ,the cranks of steam-vessels are among the heaviest pieces of forging that are wrought by ,nasmyth's steam hammer1 cast-iron being too brittle to be used for the purpose4 ,,fire-,,arms ,,and ,,projectiles4 ,illustration3 ,,fig4 #aa4 ,,machine ,,for ,,making ,,mini ,,rifle ,,bullets4 ,illustration3 ,,fig4 #a4 ,,musket ,,boring4 ,illustration3 ,,fig4 #b4 ,,rifling ,,process4 ,in the manufacture of fire-arms the chief parts consist of the metal tube from which the projectiles are to be expelled1 the stock of the musket and the carriages of great guns or cannon being only varieties of the same thing1 namely a convenient platform from which to fire the tube1 which is the real instrument4 ,in the manufacture of muskets1 pistols1 and cheap fowling-pieces1 the barrel is made from a sheet of soft iron rolled up lengthwise round a rod or 8mandril10 the edges overlapping each other1 which are then welded together2 but in the best guns the barrels are twisted1 that is1 a slip or fillet of iron half-an-inch broad and of sufficient length is twisted in a spiral round the mandril1 and then the whole is welded together4 ,the barrel is 8bored0 by means of a square-headed drill of steel turned in a kind of lathe 7fig4 #a71 and the interior afterwards polished with oil and emery-powder until it is perfectly bright and even2 the breech is then made separately1 and screwed in4 ,the best iron for gun-barrels is called 8stubb iron10 consisting of old horse-shoe nails welded together1 and is very soft and even in its grain4 ,the barrel is made red-hot and suffered to cool very slowly2 this is called 8annealing10 and it prevents any part being brittle1 and therefore liable to burst with the charge in firing4 ,rifled barrels are those which have one or more grooves cut in the inside of the barrel from the muzzle to the breech in a spiral direction1 each making one turn before it completes the length of the barrel 7fig4 #b74 ,illustration3 ,,fig4 #c4 7 ,,percussion ,,cap ,,breech47 ,illustration3 ,,fig4 #d4 7 ,,hammer ,,mechanism47 ,illustration3 ,,fig4 #e4 7 ,,rifle ,,with ,,bayonet47 ,the old 8flint0 lock has now quite gone out of use1 having been superseded by the 8percussion40 ,this is a contrivance to cause that part of the lock called the cock or hammer to strike the percussion cap with great force1 and so discharge it 7figs4 #c and #d74 ,the cap is put on to a small projection called the 8nipple10 which has a hole at the top communicating with the barrel1 and down which the spark from the percussion cap passes4 ,in rifled guns1 of late1 the use of conical balls has been introduced1 for the effect of the charge in propelling a ball rapidly out of a barrel with spiral grooves is to turn it as it passes out of the barrel1 and consequently to 8spin0 it with great velocity in one direction1 like a top2 the effect of this is to balance every part of the ball in the air and so cause it to take a true direction1 for if the merest notch or hollow existed in a spherical ball1 that part being lightest and having the least momentum would not maintain its rate so long1 and by lagging behind cause the ball to describe a part of a circle in its course4 ,it is thus that the balls from common muskets1 although rightly directed1 often fall extremely wide of the mark4 ,military muskets and rifles are fitted with bayonets1 that they may act both as lances and fire-arms 7fig4 #e74 ,illustration3 ,,gun-,,mould4 ,illustration3 ,,gun-,,boring ,,machine4 8,ordnance10 or great guns are made of cast-iron or of gun-metal 7a mixture of copper and tin71 but experiments have lately been made with wrought-iron and cast-steel1 with the view of obtaining a tougher and more durable material4 ,they are cast solid1 and afterwards bored with a machine4 ,the following account of gun-casting at ,woolwich ,arsenal appeared in the 8,times0 of ,january #bb1 #aheh3--8;,as the plug was drawn the glowing mass leapt out like a stream of silver1 filling up the moulds for two twelve-pounder howitzers that were to be cast1 and leaving a bright1 hungry-looking flame playing over them1 making everything red-hot which it approached4 ,in this workshop about twenty men and boys produce twelve brass guns per week1 as well as tangent-scales for ships' guns1 lock-covers1 brass fittings for machinery1 c41 and iron castings4 ,each gun cast requires two days to cool1 when it is removed to the turnery to be bored2 and it was to this workshop that the royal party next proceeded1 and saw the guns in all their stages of trimming1 finishing1 and boring4 ,three-quarters of an hour suffice to cut a gun to its proper length and remove the rough sand which adheres to it after casting4 ,it is then turned over to another man and another machine1 and the whole of its outside shaping and marking is completely finished in two days1 when it is again turned over to a fresh machine1 and bored and drilled ready for service in a day-and-a-half more4 ,with the present machinery the turnery at ,woolwich could finish thirty brass guns in a week1 though at this time it never completes more than ten or twelve40 ,illustration3 ,,fig4 #f4 7 ,,field ,,gun74 ,the ordinary form of 8gun0 is shown by fig4 #f4 ,the knob at the right-hand side of the cut is called the 8button10 the next division the 8vent field10 beyond this to the rim the 8first reinforce10 further on1 the 8second reinforce10 from which a cylindrical bar projects on each side for attaching the gun to the carriage1 called 8trunnions40 ,beyond this to the next rim is called the 8chace10 and beyond this again to the end the 8muzzle40 ,guns are chiefly used to throw solid round shot of cast-iron1 accurately turned to a sphere1 and the weight of these determines the character of the gun1 as a thirty-two pounder1 c41 the words 8heavy0 and 8light0 designating the thickness and consequent weight of the metal composing it4 ,there is a smaller and shorter kind of gun1 called a 8carronade10 which is held to the carriage by a projection underneath1 having a hole for a bolt to secure it1 instead of trunnions4 ,another kind of gun1 called a 8howitzer10 is of shorter proportions than the ordinary gun and larger in the bore2 it is chiefly intended to throw shells at a slight elevation4 ,the mortar is still shorter1 and of much thicker metal2 it is held to a sort of platform by trunnions at its extreme end1 and is intended to throw shells to great distances1 and at a great elevation4 ,illustration3 ,,fig4 #g4 ,,shell ,,casting4 ,illustration3 ,,bullet-,,casting1 ,,woolwich ,,arsenal4 ,illustration3 ,,fig4 #h4 7 ,,bullet ,,mould47 ,illustration3 ,,fig4 #i4 7 ,,bullets47 ,illustration3 ,,fig4 #aj4 7 ,,nippers47 ,illustration3 ,,preparing ,,lead ,,for ,,bullets4 ,the sizes of howitzers and mortars are expressed by the diameter of the shell they are intended to throw2 the largest of which at present in general use is the 8thirteen-inch40 ,this immense shell when charged weighs nearly #bjj pounds4 ,these shells or 8bombs0 as they were formerly called1 are cast hollow 7fig4 #g71 with a small opening into which a 8fuze0 or wooden tube filled with combustible matter is inserted2 they are charged with gunpowder1 which on being ignited by the fuze burning down to it1 explodes and bursts the shell into fragments1 which fly about with terrible force4 ,what are called 8shrapnel-shells10 are those shells which are filled with both gunpowder and leaden bullets1 to be scattered about by the explosion4 ,case-shot is a name given to a packet of bullets inclosed in a tin canister and used as a projectile1 the case bursts and the bullets are scattered4 ,grape-shot is the name given to a collection of nine iron balls packed up so as to be used as one4 ,hand-grenades are small shells of about three pounds' weight1 to be cast by hand4 ,bullets for the ordinary musket are simple balls of lead1 in some cases cast six at a time in moulds 7fig4 #h71 and coming out in one piece as seen at fig4 #i1 which are afterwards separated and finished off by a sort of nippers as seen in fig4 #aj2 but for the most part musket and rifle bullets are formed by compression4 ,the bullets for the ,mini rifle are made by machinery2 they are of a conical form1 with a hollow at the base into which a small plug of box wood is fitted1 this end being towards the powder receives the whole force of the explosion1 the effect of which is to drive in the plug and open out the bullet1 thus fitting it tightly into the grooves of the rifle and preventing any loss of power by the escape of the gases resulting from the combustion of the powder4 ,the machine for making these bullets is shown at fig4 #aa4 ,the following is an account of it1 taken from the 8,times03-- 8,like all the machines here1 these are perfectly automatic4 ,coils of solid leaden piping are hung in it1 which it unwinds1 cuts to the required length1 stamps with steel dies into the form of a ,mini bullet1 and then conveys away into boxes4 ,each machine has four dies1 which cut1 stamp1 and pass into boxes thirty-six bullets per minute1 giving for each machine an average of #g1jjj per hour4 ,there are four of such machines1 which thus each day turn out #cjj1jjj ,mini bullets2 but1 of course1 as they never tire1 the number produced can at any time be doubled by leaving them to work all night4 ,they are so simple in their construction that one man could easily attend to them all4 ,it was a curious contrast to the silent rapidity with which these deadly messengers were formed1 to watch a number of men and boys working near them casting round musket-balls for ,shrapnel shells1 in the old style of hand work4 ,by this method two persons can only rough-cast seven cwt4 of bullets per day1 or about #ab1ejj1 which it takes two persons another day to trim4 ,thus1 four hands1 with a great consumption of fuel to keep the lead always melted can only produce #f1jjj bullets per day or #a1jjj less than each machine produces in one hour40 ,the machines for making the box wood plugs are also described3-- 8,each of these was managed by a child1 who kept it properly fed with small sticks of box1 which the machine converted into plugs at the rate of #ae1jjj in nine hours1 or nearly #cjj1jjj per day for them all40 ,rockets1 as used for projectiles1 are similar to those in ordinary use1 but that they have iron cases and are made to start from an iron tube1 down which the stick passes1 and which directs the course of their flight4 ,they are made of various weights1 the largest being thirty-two pounds4 ,these enormous rockets pass to a very great distance and are made either to explode like shells1 or burn fiercely for several minutes1 like what are called 8carcases10 thus setting fire to houses1 c41 against which they may be directed2 but hitherto their course has been but little under control1 and therefore not much to be depended on4 ,they cause great confusion in masses of troops1 when directed against them4 ,,percussion ,,caps4 ,illustration3 ,,percussion ,,cap ,,machine1 ,,woolwich ,,arsenal4 ,illustration3 ,,fig4 #a4 7 ,,perforated ,,copper47 ,illustration3 ,,fig4 #b4 7 ,,cap47 ,illustration3 ,,fig4 #c4 7 ,,perforated ,,plate47 ,illustration3 ,,fig4 #d4 7 ,,spreading ,,fulminating ,,powder47 ,illustration3 ,,fig4 #e4 7 ,,tamping ,,machine47 ,illustration3 ,,fig4 #f4 7 ,,varnishing ,,machine47 ,these are little hollow cups of copper having a fulminating substance at the bottom1 so that when put on to the 8nipple0 of the gun and struck by the 8hammer10 the fulminating powder explodes1 and the spark passing down the hole in the nipple discharges the gun4 ,to prepare the fulminating powder for these caps1 let #ajj grains of mercury be dissolved in a measured ounce-and-a-half of nitric acid1 and when cold let two ounces of spirits of wine be added1 and the whole put into a ,florence-oil flask made perfectly clean1 and let it be placed in the open air2 copious fumes will pass off and a violent action take place1 during which a white crystalline powder will be deposited2 as soon as all action has ceased and the liquid cooled1 pour the whole on a filter of blotting paper1 and let the fluid pass through1 wash the powder which remains on the filter with a little water1 and let it dry1 without heat4 ,this is fulminating mercury1 which is a highly dangerous compound1 and should be kept in a bottle with a cork1 and not a stopper1 as the friction of this against the neck of the bottle might cause an explosion4 ,at the ,arsenal at ,woolwich is a machine 7shown at the head of this article7 which makes the caps complete4 ,it is fed by a band of thin copper about two inches wide1 out of which pieces are punched in the form of a thick cross1 leaving the perforated copper as shown in fig4 #a2 these pieces are punched or 8struck up10 and expelled as perfect caps of the form of fig4 #b1 at the rate of about #ajjj per minute4 ,the caps have next to receive their charge of fulminating powder1 which is done by dropping them into a perforated plate 7fig4 #c71 capable of receiving many hundreds2 this is covered over by two other plates1 each perforated to correspond1 but the upper one made to shift1 so that in one position the holes correspond1 and in the other they do not1 but remain as small shallow dints4 ,a portion of the fulminating powder is put on this plate and scraped all over it by means of a piece of paste-board 7fig4 #d71 so as to fill all the little dints2 the plate is then shifted and the holes made to correspond1 when the powder falls through into the percussion caps1 each one of which thus receives a definite charge4 ,the next process is to press it down into the cap1 so as to prevent it falling out4 ,for this purpose the plate full of caps is removed to a machine 7fig4 #e71 having a row of little stoppers1 which are moved rapidly up and down1 the pressure being exactly regulated by flat leaden weights1 suspended so as to give only so much pressure as will consolidate the powder1 without exploding it4 ,they are next removed to a third machine called the 8varnishing machine0 7fig4 #f74 ,this has a trough of varnish1 made by dissolving shellac in spirits of wine1 into which a row of wires dip1 and by a turn of the hand convey the minute portion of varnish on their points into the caps1 row after row4 ,this varnish dries in a few minutes1 and causes the fulminating powder to adhere2 the caps are now complete4 ,the old form of caps was a simple short cylinder1 but it is found better to allow the four little flaps to remain on1 that the right end may be distinguished and instantly placed on the nipple the proper side downwards1 which cannot otherwise so readily be done in the dark1 and when the hands are benumbed with cold4 ,,pumps ,,and ,,fire ,,engines4 ,illustration3 ,,fig4 #a4 7 ,,common ,,lifting ,,pump47 ,pumps are used for lifting fluids above their level into some higher situation1 such as from the hold of a ship or from a well4 ,fig4 #a shows the different parts of a common 8lifting pump20 a a is a cylinder1 b a piston rod or 8plunge10 c the sucker made of leather to fit nicely the cylinder1 d a valve in the sucker to open upwards1 e a valve fixed to the cylinder1 also to open upwards1 f a box with a spout4 ,illustration3 ,,fig4 #b4 7 ,,air ,,pump47 ,the piston being raised by lowering the handle of the pump1 a partial vacuum is formed below the upper valve1 which shuts down directly the piston is raised by the pressure of the air2 this vacuum causes the external air to force the water some way up the tube g4 ,on the piston descending1 the lower valve is forced down and the upper one opened1 this keeps the water where it is and allows the piston to descend without forcing the water down again1 and on its being raised a second time the upper valve shuts and the lower one opens1 the water being drawn up still higher1 and this takes place till the box at the top is full to the spout1 when it runs out4 ,the air-pump is on the same principle1 and is generally made with two cylinders worked by means of a 8rack0 and wheel 7fig4 #b72 this is only to save time1 instead of pumping water it pumps out air from any vessel called a 8receiver10 because it receives any object to be placed in a 8vacuum10 that is to say a partial vacuum1 for the air-pump cannot produce a vacuum1 as the air is only partly removed by each stroke of the piston1 leaving the air more rarefied inside2 and although each stroke of the piston increases the rarefaction1 yet it cannot get all1 as it merely takes part1 and always leaves part4 ,illustration3 7 ,,fire ,,engine47 ,illustration3 ,,fig4 #c4 7 ,,air ,,chamber47 ,fire and garden engines are only applications of the pump to different purposes4 ,the fire-engine has generally two cylinders and pistons1 and has moreover an air-chamber for the purpose of making the stream of water continuous4 ,it acts in this way3--,the water is forced by the power of those who are pumping the engine into a vessel air-tight and full of air1 having an opening which joins the 8hose0 at its lower part2 the result is1 that as the water is forced in faster than it can well escape1 the air above it--becoming greatly compressed1 and by its expansion between each stroke of the pistons--forces the water out1 and so continues the stream or jet4 ,fig4 #c shows this air-chamber2 a joins to the hose c1 and b is in union with the forcing-pumps of the engine4 ,the air is represented as it would be compressed to about half its bulk1 for it at first filled all the air-chamber down to the openings4 ,,valves4 ,illustration3 ,,fig4 #a4 7 ,,flapper ,,valve47 ,illustration3 ,,fig4 #b4 7 ,,ball ,,valve47 ,illustration3 ,,fig4 #c4 7 ,,plug ,,valve47 ,illustration3 ,,fig4 #d4 7 ,,closed ,,piston ,,valve47 ,illustration3 ,,fig4 #e4 7 ,,open ,,piston ,,valve47 ,valves are contrivances to admit the passage of fluids or gases by their own pressure in one direction1 and in such a manner that the same pressure shall of itself prevent their return or passage in the opposite direction1 as in fig4 #a1 which is the piston of a common pump4 ,there are almost innumerable varieties of valves1 one consists of a ball of metal fitting into a cup which has a hole at the bottom 7fig4 #b74 ,another 7fig4 #c71 is a plug of a conical shape fitting in the same way1 and having a rod affixed to the top which passes through a hole in a piece of metal so as to guide it in its ascent and descent2 this is the kind of valve used as a 8safety-valve0 in steam boilers1 but having the pressure regulated by a spring or weights4 ,figs4 #d and #e are representations of a kind of valve which forms the piston itself1 and is very useful as a piston for a square wooden tube for temporary purposes1 as on board ship1 where any number may be fitted up at little trouble1 time1 or expense4 ,there are many other valves besides these1 as the sliding valves of steam-engines1 c4 ,,wheels4 ,illustration3 ,,fig4 #a4 7 ,,fly-,,wheel47 ,illustration3 ,,fig4 #b4 7 ,,power ,,gears47 ,illustration3 ,,fig4 #c4 7 ,,beveled ,,gears47 ,illustration3 ,,fig4 #d4 7 ,,side-,,cogged ,,gear47 ,illustration3 ,,fig4 #e4 7 ,,ratchet ,,gear47 ,illustration3 ,,fig4 #f4 7 ,,capstan47 ,illustration3 ,,fig4 #g4 7 ,,pulleys47 ,illustration3 ,,fig4 #h4 7 ,,endless ,,band ,,pulleys47 ,scarcely any kind of machinery can be constructed without wheels of some kind--they serve almost numberless purposes4 ,the fly-wheel 7fig4 #a7 serves to produce a continuous motion1 from its size and weight giving it a tendency to go on1 and in this way causing it to fill up the intervals of unequal action1 as in the ascent and descent of the piston in a steam-engine4 ,the toothed-wheel serves to give motion to other wheels1 and this at a certain rate either greater or less than its own1 according to its size1 and consequently the number of its teeth2 thus a wheel with a hundred 8cogs0 or teeth united to one with but fifty1 causes this to go round twice while the larger one passes round but once2 but a large wheel turned round by a small one1 although it moves more slowly yet does so with increased power just in proportion to its slowness 7fig4 #b74 ,the bevel-wheel 7fig4 #c7 is used to change the direction of a shaft1 and for all the other purposes of a toothed-wheel1 from which it differs only in the position of the teeth or cogs4 ,wheels are sometimes made to answer the purposes of bevel wheels1 by having the cogs on the surface of the one wheel1 and the other as an ordinary toothed-wheel 7fig4 #d74 ,the ratchet-wheel 7fig4 #e7 is a wheel with its teeth pointing in one direction like the teeth of a saw1 and into which a tongue of iron is made to fall1 so that the wheel can only be turned in one direction4 ,these wheels are used where the machinery is liable to run back if left1 as in the 8crane10 c4 ,the capstan 7fig4 #f7 is a kind of ratchet wheel1 and is so made that long spokes may be placed in the holes1 to be moved round by men1 and taken away when out of use2 it is a very powerful piece of machinery1 and is used for 8weighing anchor0 7see 8,anchors074 ,the pulley 7fig4 #g7 is a series of wheels used to increase power by diminishing the rate of movement2 they are much used in the rigging of ships1 and are then called 8blocks40 ,there are different ways of connecting wheels so as to communicate the motion of one to another2 they may be toothed as before described1 or a 8lathe-band0 may be passed over them4 ,this may be either round or cord-like1 and made of cat-gut1 or flat and made of leather or gutta-percha4 ,this mode of producing motion is very useful where evenness and smoothness of action are required1 or where the wheels are at a considerable distance apart2 they have their ends united so as to form a ring1 or endless band1 and are sometimes used to communicate motion to a great many wheels1 as seen in fig4 #h4 ,the eccentric-wheel has its axis out of the centre2 it is used for the same purpose as a crank1 but the action is more continuous and even4 ,while the crank is most frequently used to produce a circular or rotatory motion from an up-and-down motion1 the eccentric-wheel is more commonly used to produce an up-and-down motion from a rotatory one 7fig4 #i74 ,wheels take almost every variety of form1 and are not1 in some cases1 even round2 in winding yarn on to bobbins1 where a motion is required of a constantly varying rate1 two elliptical wheels are made to act on each other1 the end of one being approximated to the centre of the long axis of the other1 7fig4 #aj74 ,illustration3 ,,fig4 #i4 7 ,,eccentric-,,wheel47 ,illustration3 ,,fig4 #aj4 7 ,,two ,,eccentric-,,wheel ,,gears47 ,wheels for carriages are used to diminish friction1 by causing the 8tire0 or smooth outer edge to roll upon the surface instead of being rubbed2 all the friction in wheels is in the centre or axle1 which being turned smooth1 and greased or oiled1 works very easily4 ,carriage wheels are made to revolve upon a fixed axle1 and each wheel revolves independently of the other1 but in railway-carriages and engines1 the wheels are united in pairs1 and the axle revolves with them1 the weight being borne outside of the wheel on a small part of the axle which projects4 ,the various parts of a wheel are the box or 8nave0 which is the centre part1 the 8spokes0 or those bars which connect it with the centre edge or felloes1 and the 8tire10 an iron band binding the whole together4 ,wheels for gun-carriages are made at ,woolwich ,arsenal by machinery4 ,the following is a description of them1 taken from the 8,times0 newspaper3-- 8,here a few unskilled labourers superintending the machines produce forty complete gun-carriage wheels a day1 though all their component parts are made of the hardest woods--viz41 elm for the naves1 oak for the spokes1 and ash for the felloes4 ,the novelty here was the new mode in which a wheel is fitted together4 ,instead of by hand1 as formerly1 the pieces are all laid together on the ground1 and of course in a circle1 around the outside of which are six small hydraulic rams1 with the head of the piston of each curved so as to form a segment of a circle touching the outside portion of the wheel4 ,one small steam-engine pumps the water into all these with an equal pressure1 which1 as it increases1 forces the felloes into the spokes and the spokes into the nave of the wheel1 with such force as to compress the whole1 by a strain of #bej tons1 into the solidity of one piece40 ,paddle-wheels are made to revolve with their lower part in water1 and are furnished with a series of short boards fixed to the tire of the wheel1 which is generally double1 that they may be better held on2 these boards or paddles take a great hold on the water and cause the resistance which is necessary to move the vessel4 ,the wheel of a watermill is constructed in the same way4 ,,watermills4 ,illustration3 7 ,,watermill47 ,watermills are those kind of mills1 the motion of which is derived from the flow of a stream of water against the lower part of a large wheel1 provided with paddle-boards similarly to the paddle-wheels of steam-vessels2 or else by the weight of a stream of water falling against the upper part of the wheel from a spout or trough2 the former of these is called the under-shot1 and the latter the over-shot mill4 ,the former is used where there is a large body of water flowing at a sufficiently rapid rate1 and the latter kind where there is but a small supply1 the whole of which is often used for driving the mill2 but other circumstances1 of position1 c41 may determine which shall be used4 ,the large wheel being thus driven round1 any kind of machinery may of course be attached1 according to the nature of the work to be done4 ,like windmills these watermills are for the greater part superseded by steam power2 the locality1 c41 must determine which can be used with most advantage4 ,,windmills4 ,illustration3 7 ,,windmills47 ,these picturesque objects are buildings containing machinery1 to be driven by the wind1 for grinding corn1 sawing wood1 and any other purpose that may be required4 ,they consist of a basement1 generally of stone or brick1 and a superstructure surmounted by a sort of dome capable of being turned round4 ,from this dome projects the shaft of a wheel1 and on this is fastened four fans or sails made of long bars of wood crossed by shorter ones2 these being covered with canvass1 form a surface to catch the wind4 ,these sails are placed obliquely to the front of the cross1 so that when the wind blows upon them right in front1 they are at an angle with it1 they are therefore turned round2 for the wind which pushes them from the front1 as they are oblique1 tends also to push them on one side2 when once in motion1 being heavy1 they form a sort of fly-wheel to the machinery4 ,the dome has several small wheels attached to its lower border1 to act as friction rollers and cause it to be easily turned round 7which is often required71 that the sails may be made to face the wind in whatever direction it may blow2 this is sometimes done by ropes attached to the dome1 but is more frequently effected by means of a small set of sails1 shown in the cut1 which are placed at right angles to the large set1 so that when the wind acts on the large sails the small ones are not affected2 but should the wind shift1 these small ones begin to move1 and they are connected with a toothed wheel acting upon a band which surrounds the dome2 this is therefore caused to turn round whenever the small sails are turned1 and as the dome turns1 it brings with it the large sails until they are in the right position4 ,these sails are generally fixed not quite upright1 but inclined with their fronts looking a little upwards1 which is found to be the best position to catch the wind4 ,,syphons4 ,illustration3 ,,fig4 #a4 7 ,,sucking ,,syphon47 ,illustration3 ,,fig4 #b4 7 ,,glass ,,ball ,,on ,,sucking ,,tube47 ,syphons are bent tubes for drawing off liquids from cisterns1 butts1 c41 where there is no tap1 and where it would be inconvenient to make any second opening4 ,fig4 #a gives the outline of the most usual form of syphon2 these are only used for liquids that may be drawn into the mouth without injury1 such as spirits from casks4 ,the mode of using the syphon is this--the bottom of the longest leg a is stopped with the palm of the hand1 the tap is then turned on and the mouth applied to the small tube c1 the air is then drawn out by sucking2 the liquid rises and fills both legs of the instrument1 the tap is turned off1 and the syphon is full4 ,now as the leg a is longer than the leg b1 the fluid in it weighs more than that in b1 and sinking down draws the fluid in b up1 and so on till all is drawn from the cask4 ,syphons are generally made of copper1 but gutta-percha would answer exceedingly well4 ,fig4 #b represents a contrivance for drawing off acids1 c41 which would injure the mouth2 the ball prevents the acid rising into it1 as the mouth is removed directly it begins to fill1 which as the instrument is of glass1 can easily be seen4 ,,stop-,,cocks ,,or ,,taps4 ,illustration3 ,,fig4 #a4 7 ,,open ,,tap47 ,illustration3 ,,fig4 #b4 7 ,,closed ,,plug47 ,illustration3 ,,fig4 #c4 7 ,,open ,,plug47 ,illustration3 ,,fig4 #d4 7 ,,closed ,,tap47 ,illustration3 ,,fig4 #e4 7 ,,spouted ,,tap47 ,taps are used for the purpose of letting off or stopping at pleasure the flow of liquids from vessels or through pipes4 ,the forms of stop-cocks are very various1 but the form shown at fig4 #a is by far the most general2 it consists of a short curved tube1 having an upright cylinder in the centre in which a plug with a handle turns2 this plug is perforated in the direction of the length of the handle1 so that when this is turned crosswise the communication is shut off 7figs4 #b1 #c1 and #d74 ,the 8nose0 or end of the tap is sometimes prolonged into a spout1 for filling bottles1 c41 as in fig4 #e4 ,illustration3 ,,fig4 #f4 7 ,,open ,,safety ,,tap47 ,illustration3 ,,fig4 #g4 7 ,,closed ,,safety ,,tap47 ,illustration3 ,,fig4 #h4 7 ,,american ,,wooden ,,tap47 ,illustration3 ,,fig4 #i4 7 ,,safety ,,tap ,,key47 ,illustration3 ,,fig4 #aj4 7 #d-,,way ,,tap 7a-b1 c-d747 ,illustration3 ,,fig4 #aa4 7 #d-,,way ,,tap 7a-c1 b-d747 ,the safety tap differs somewhat from the ordinary tap1 a section is seen in figs4 #f and #g2 the plug is hollow and forms the nose or spout itself1 this plug is only perforated on one side1 so that it has to be turned round half-way instead of quarter-way as in the common tap4 ,the upper part of the cylinder has an opening 7of different shapes7 leading to the top of the plug1 c41 a key being made to fit it 7fig4 #i74 ,the ,american wooden taps 7fig4 #h71 are just like it1 but have the handle united instead of a key4 ,the four-way tap is a clever contrivance for uniting four passages in alternate pairs2 figs4 #aj and #aa indicate the different positions of the plug4 ,this kind of tap was formerly an important part of the steam-engine1 and allowed the steam alternately to enter above and below the piston4 ,,filters4 ,illustration3 ,,fig4 #a4 7 ,,blotting-,,paper ,,filter47 ,illustration3 ,,fig4 #b4 7 ,,filtering ,,stone47 ,filters are contrivances for separating substances from liquids which are not dissolved in them2 but in the most common acceptation of the term1 filters are vessels used for separating the impurities from water4 ,filters on the very large scale required by the water companies consist of sand or gravel so contrived that the water shall drain through them4 ,this1 indeed1 is the natural way in which well or spring water is filtered2 for the rain falling on the surface of the earth sinks down through such substances as gravel and sand1 and lies in beds at the bottom1 when it meets with stone or clay1 through which it cannot sink 7see 8,artesian ,wells074 ,this water when drawn up is in most cases very bright1 as it has been strained through the sand or gravel in passing downwards4 ,the best substance through which to filter water for household use is sponge pressed together with some force1 and this is the usual plan adopted in all the earthenware filtering vessels sold2 but there is usually a layer of sand or some other substance placed below1 which is useless or worse1 as it often becomes foul and taints the water4 ,if the water has a bad odour1 a few pieces of newly-burned charcoal placed in it above the sponge will purify it 7see 8,charcoal074 ,filters for other purposes1 and for any small quantity of liquid1 may be made by cutting a piece of white blotting paper round1 and then folding it into quarters and partially opening it 7fig4 #a72 this if put into a funnel forms a convenient filter for any substance to be brightened1 as water1 vinegar1 or wine4 ,a particular kind of porous sandstone used to be hollowed out and used as a filter1 but these filtering-stones are now but seldom used1 except in the case of self-filtering cisterns1 which are made by enclosing the inner opening for the tap in slabs of porous stone1 so as to form a box within the cistern 7fig4 #b72 by this contrivance1 when the tap is turned1 only that water escapes which has been filtered4 ,it is necessary to have an air-tube to let the air in as the filtered water runs out1 and to let the air out as the water filters in from the cistern4 ,even in these cisterns a box of slate or other substance having several holes with sponges pressed into them would answer much better1 as these could be removed from time to time1 washed1 and returned4 ,filters1 of course1 can only separate mechanical impurities1 such as dust1 insects1 c41 for if sugar or salt were put into the water1 all the filtering that could be used would not separate them when dissolved1 and thus it is that well and spring water1 although perfectly bright1 are still very impure1 containing much lime and carbonic acid dissolved in them1 together with other matters1 as iron1 c41 which are not separable by filtration2 if it be desirable to separate them1 distillation must be had recourse to 7see 8,distillation074 ,some of these1 however1 as lime1 may be separated by boiling the water for some time1 which causes the lime to fall down in the form of chalk1 and adhere to the bottom of the vessel--hence the 8fur10 as it is called1 in kettles4 ,water containing lime1 although quite 8hard0 and unfit for washing purposes1 is made sufficiently 8soft0 for use by boiling4 ,,presses4 ,presses are contrivances for compressing or squeezing together substances that may require to be so treated1 as in the case of extracting the oil from seeds1 c4 ,the earliest presses were simply heavy stones or pieces of metal1 put on one after the other2 but the great inconvenience and loss of time incurred in putting on and taking off these1 soon led to the screw and lever1 which form the usual screw press4 ,the screw is fixed at one end in a socket and is turned round by a long bar of iron or wood1 and as the 8worm0 works in a corresponding hollow screw which is fixed1 it ascends or descends slowly but with great power4 ,but by far the most powerful contrivance of this kind is the 8hydraulic0 press2 this machine is not only used as a press1 but also to raise great weights1 and for many other purposes4 ,the hydraulic press consists of a strong iron cylinder having a solid piston exactly fitting to it1 this piston is raised by forcing water under it by means of a pump2 the principle depends upon the peculiar property which water and every other fluid has1 of exerting1 when confined in a given space1 an equal pressure upon every part of that space2 thus if one pound pressure be made upon one square inch1 the water will press with one pound power upon every square inch of surface that it comes into contact with2 for example1 suppose a cylinder1 the piston of which is one foot measurement on the face--this foot contains #add square inches--and from the bottom of the cylinder a tube should be made to rise a few feet above the piston1 and that this tube should have an area of one inch2 then one pound weight of water poured in at the top of this tube would raise #add pounds weight placed on the piston1 for these #add pounds would press but one pound on each inch1 and the pound of water would have the whole of its weight on the one inch of the tube1 they would therefore balance each other4 ,but instead of pouring in the water1 let a piston be fitted to the tube2 a man with his hand can easily exert #ajj pounds pressure on this1 and the result would be that he would raise #ad1djj pounds or nearly six-and-a-half tons1 and if to this small piston a handle and valves be fixed so as to make a pump of it he can easily pump in water at a pressure of two or three hundred pounds to the square inch2 and if instead of the large piston containing one foot area it has three or four feet1 then the weight raised would be very great2 indeed there is no limit to the power of this instrument but the strength of the material used4 ,it must however be observed that when the piston descends1 say six inches1 it does not raise the six-and-a-half tons six inches1 but only a hundred-and-forty-fourth part of that distance1 so that the piston would have to be raised and depressed six inches #add times in order to raise the six-and-a-half tons six inches4 ,but this is such a saving and concentration of labour that the application of the hydraulic press is becoming more in demand every day4 ,,stills4 ,illustration3 ,,fig4 #a4 7 ,,retort47 ,illustration3 ,,fig4 #b4 7 ,,common ,,still47 ,illustration3 ,,fig4 #c4 7 ,,small ,,portable ,,condenser47 ,these are vessels of different kinds used in distilling1 that is1 when any volatile product has to be converted into vapour and afterwards condensed1 for the purpose of separating it from various matters not otherwise separable4 ,one of the oldest forms of still is that even yet used in most chemical operations1 called the 8retort0 7fig4 #a74 ,it is blown out of glass in one piece1 is easily made of all sizes1 not exceeding a few gallons2 it is chiefly used for distilling small quantities of fluids1 and those which act on metals1 as the acids4 ,for some purposes1 chiefly those requiring a very high temperature1 earthenware retorts are used1 and in other cases retorts made of platinum2 the retort is often 8tubulated10 a name given to those with an orifice in the upper part having a stopper fitted to it1 this opening is useful to introduce any substance while the body of the retort is already partly filled with its contents1 or to add more of anything from time to time as it distils over4 ,an indispensable adjunct to the retort is a 8receiver0 for condensing the liquid distilled2 this is generally of a globular form1 with an opening to receive the spout of the retort1 which is also frequently 8tubulated0 that it may be attached by a bent tube to a second or third receiver4 ,the receiver is to be kept cool1 and this is generally done by a stream of cold water being poured on it1 or a cloth dipped in cold water being spread over it1 c4 ,the stills properly so called1 such as are used in the manufacture of large quantities of liquids1 as1 for example1 in the distillation of spirit1 are generally made of copper tinned inside to prevent the formation of verdigris1 and consist of a body1 a head1 and a condenser1 the common form of which is seen at fig4 #b4 ,the condenser consists of a long tube coiled up into a spiral and placed in a large tub of water1 having a supply tube to let in cold water at the bottom1 and one for the exit of the hot water at the top1 for hot water being lighter than cold1 rises up to the top of the tub4 ,a very good form for a small portable condenser may be seen at fig4 #c1 in which a constant current of cold water is made to pass through the outer tube1 and so keep the inner one cold4 ,illustration3 ,,fig4 #d4 7 ,,flasks ,,and ,,bent ,,tube47 ,illustration3 ,,fig4 #e4 7 ,,two ,,tubes47 ,a distilling apparatus for experiments in chemistry can easily be made with flasks and bent glass tubes1 fig4 #d1 or even by means of pieces of tube alone as in fig4 #e1 one being bent and the other straight2 the tubes and flasks can be united by means of corks perforated by a round or keyhole file4 ,empty oil-flasks serve well for this purpose1 they can readily be cleansed by putting a little oil of vitriol into them1 shaking it well about1 and then washing them out with clean water4 ,,blowpipes4 ,illustration3 a4 7 ,,common ,,blowpipe47 ,illustration3 b4 7 ,,reservoir ,,blowpipe47 ,illustration3 c4 7 ,,reservoir ,,blowpipe47 ,illustration3 d4 7 ,,home-,,made ,,blowpipe47 ,blowpipes may be considered as miniature blast-furnaces4 ,they are little instruments used to force--by means of air blown from the mouth--the flame of a lamp or candle into a jet of flame so fierce that the very highest heat can be produced by it4 ,various forms of blowpipes are shown in the figures2 the common blowpipe1 used by gas-fitters1 tinmen1 c41 is shown at a2 better blowpipes have generally some reservoir to contain the condensed breath and so prevent it issuing into the jet2 the bulb shown at b is for this purpose and also the conical part of c4 ,very good and cheap blowpipes may be made by bending a piece of glass tube into the form shown at d1 adding a perforated cork and a small piece of bent glass tube fixed as in the figure4 ,the end of the small tube1 intended to produce the jet1 should be held in the flame of a lamp or gas till it is red hot and turned round all the while2 in this way the hole will gradually become smaller as the melted sides collapse1 forming a neat round hole about the size to admit a fine needle2 with this blowpipe a very great heat can be produced1 and it can be easily repaired4 ,the oxy-hydrogen blowpipe is a contrivance for forcing a jet of oxygen and hydrogen gases--mixed together in the proportions in which they form water--through a small orifice and setting fire to it2 this produces the very highest heat4 ,almost any substance can be fused by it1 but the experiment should not be made unless with a proper apparatus1 as the flame will be sure to run down the tube and explode the mixed gases with dangerous violence4 ,a common flame is merely a cone of vapour burning on the surface where it comes into contact with the air1 and therefore gives out but little heat1 but when air is forced into it1 a small blue cone of solid flame is projected1 which gives off more heat than the hollow cone4 ,,thermometers4 ,illustration3 ,,fig4 #a4 7 ,,bulb ,,and ,,stalk ,,with ,,mercury47 ,illustration3 ,,fig4 #b4 7 ,,scaled ,,thermometer47 ,illustration3 ,,fig4 #c4 7 ,,register ,,thermometers47 ,the thermometer is an instrument for determining the temperature of the air or any other fluid into which it may be introduced4 ,the thermometers in general use contain mercury1 but some contain colored spirit2 yet1 as mercury is most generally used1 it will be only necessary to say of spirit thermometers1 that they act on the same principle4 ,a thermometer consists of a glass ball having a long thin hollow tube rising out of it and attached to a graduated scale--the bore or hollow of the tube is very small1 scarcely sufficient to admit a piece of sewing cotton4 ,the ball or bulb and part of the stalk are filled with mercury by holding a lamp to the ball till the air is nearly all expelled by its expansion--for heat expands air very greatly--and putting the end of the stalk into a vessel of the fluid4 ,when the lamp is removed the air in the bulb cools and therefore contracts1 by which means the mercury is forced up the fine tube1 very nearly filling the bulb4 ,the bulb is then held downwards and the mercury so heated that it expands1 as did the air1 till it fills the whole of the bulb and stalk up to the very top2 the top is then melted with the blow-pipe 7see 8,blowpipes071 and the glass1 running together1 closes up the bore at the end4 ,as the mercury cools it contracts1 and consequently1 occupying less space1 falls down in the stalk pretty close to the bulb1 the space above it is therefore empty1 and forms a 8vacuum40 ,now1 therefore1 we have an instrument1 consisting of a bulb and stalk half-filled with mercury 7fig4 #a74 ,upon any amount of heat being applied to the bulb1 the mercury in it expands1 and rises in the stalk in proportion to the amount of heat applied1 or shrinks and sinks down again as it cools4 ,the next thing to be done is to form a 8scale0 by which the height of the mercury in the stalk may indicate some known or recognised temperature4 ,there are three scales in use1 8,fahrenheit's10 8,reaumur's10 and the 8centigrade40 ,the scale universally used in ,england is ,fahrenheit's1 although both this and ,reaumur's are sometimes marked on the same thermometer 7fig4 #b74 ,fahrenheit's scale is formed thus3--,the bulb of the thermometer is placed in boiling water1 and the height to which the mercury rises is marked by a scratch on the stalk2 it is then put into snow or ice in the act of melting1 and another scratch is made where the mercury has descended to4 ,the space between these two marks is divided into #ahj equal parts called degrees1 and these divisions are carried upwards to nearly the end of the stalk and downwards to near the bulb2 the upper scratch1 indicating the heat of boiling water1 is marked #bab1 and the lower one1 which marks the freezing point of water1 being #ahj divisions lower1 will be #cb2 and of course1 #cb degrees lower will be #j1 and is called 8zero40 ,on the scale of ,reaumur's thermometer the zero or point marked #j1 is at the freezing point of water1 and the boiling point is marked #hj 7fig4 #b74 ,the centigrade differs from ,reaumur's only in having the space between the boiling and freezing point of water divided into #ajj parts instead of #hj4 ,what are called 8register thermometers0 have two bulbs1 stalks1 and scales1 on the same instrument 7fig4 #c72 one bulb is filled with mercury1 and the other with colored spirit4 ,in each stalk a piece of enamel1 about half-an-inch long and fitting the cavity1 is introduced2 the one in the mercury is to register the highest1 and that in the spirit to register the lowest degree of heat4 ,they act in the following manner3--,the spirit1 being very liquid or thin in its nature1 wets the enamel and passes by it when it rises in the stalk1 so that the elevation of temperature does not affect its position1 but when the spirit sinks down it drags the enamel with it1 thus registering the lowest temperature1 so that the distance the enamel is found down the stalk indicates how low the spirit may have descended in any particular time1 say a night4 ,with respect to the mercury1 it is not of a nature to adhere to the enamel1 and therefore instead of passing it pushes it up in the stalk as it rises1 but on descending leaves it behind1 the height at which the enamel is found up the stalk indicating the highest point to which the mercury had risen1 and consequently the highest temperature4 ,to adjust the instrument1 a slight tap or shake will make the index in the spirit tube fall to the surface of the spirit1 where it is held by the adhesive quality of the liquid1 and by the same process that in the mercurial stalk will fall to the surface of the mercury1 but will not penetrate it1 owing to its great density4 ,,barometers4 ,illustration3 ,,fig4 #a4 7 ,,bent ,,glass ,,tube47 ,illustration3 ,,fig4 #b4 7 ,,tube ,,immersed ,,in ,,mercury47 ,illustration3 ,,fig4 #c4 7 ,,weather ,,glasses47 ,the barometer is designed to indicate the weight or pressure of the air on any surface1 at any particular time or place2 for the air1 although invisible1 is still of considerable weight1 as there are many miles of it pressing from above downwards on all parts of everything upon the earth1 and the barometer is for the purpose of ascertaining how much this pressure amounts to4 ,it is formed as follows3 a piece of glass tubing1 about three feet long1 is first closed at one end1 then turned up at the other and expanded 7fig4 #a72 when this tube is filled with mercury and held with the bulb downwards1 the mercury sinks in the stalk to a certain height 7say twenty-nine inches71 and that height shows the weight or pressure of the air4 ,the reason of this will be understood by supposing a piece of straight glass tubing1 three feet long1 to be closed at one end and then filled with mercury2 if the finger be placed on the end not closed1 and that end turned downwards and put into a basin of mercury 7fig4 #b7 before the finger is withdrawn1 the fluid1 if the air exerted no pressure1 would all sink down from the inside of the tube into that in the basin1 leaving a 8vacuum0 or empty space in the hollow of the tube1 but it is evident if the air exerted any pressure on the surface of the mercury in the basin1 this pressure would force the mercury up the tube 7for there is no opposing pressure in an empty space71 and that the mercury would rise higher and higher the greater the the pressure4 ,well1 then1 the air really exerts this pressure1 and to such an extent as to raise the mercury somewhere about thirty inches in height1 and the pressure necessary to do this is found by calculation to be about fifteen pounds upon every square inch of surface4 ,the barometer tube is divided into a scale of inches and fractions of inches4 ,what are called weather glasses1 are barometers having the lower part brought up by a curve1 and a small weight resting on the mercury in it1 which being attached to a corresponding weight by means of a cord running over a little wheel or pulley fixed to hands moving round a sort of dial1 turns them as the mercury rises or sinks 7fig4 #c71 for as the mercury falls in the stalk it must of course rise in the short stalk of the curve2 the hands by these means are turned round1 and the rise or fall of the fluid will cause them to point to 8fair10 8rain10 c41 as the case may be1 for these names are marked where a corresponding change of the weather may so influence the weight of the air1 as to raise or depress the mercury1 and so bring the hands in a position to point to them4 ,,pendulums4 ,illustration3 ,,fig4 #a4 7 ,,gridiron ,,pendulum47 ,illustration3 ,,fig4 #b4 7 ,,mercurial ,,pendulum47 ,any weight attached to a rod or wire so that it can swing freely may be called a 8pendulum40 ,but for the purpose of time-keeping1 a much more accurate instrument is required2 the rate of vibration or oscillation of the pendulum1 does not depend upon the weight of the ball or 8bob0 at the lower end1 but upon the distance of this from the point at which the upper end turns1 nor does the rate of oscillation depend upon the distance through which the weight traverses1 for every pendulum will vibrate at the exact rate 7with certain restrictions7 at which it is set off1 until it ceases1 although the distance through which it traverses1 decreases at every vibration2 these facts are taken advantage of in adapting the pendulum to the purposes of regulating the time a clock shall keep--the longer the pendulum the slower the vibrations4 ,now1 as everything in nature is expanded by heat and contracted by cold1 so a pendulum is constantly varying in length by every change of temperature1 and1 as a consequence1 the rate of the clock to which it is attached will also vary4 ,pendulums which have an arrangement to obviate this variation1 are called 8compensating0 pendulums2 the best in use are of two kinds1 one called 7from its appearance7 the 8gridiron10 the other the 8mercurial10 this last is the most accurate1 and is used in nearly all good astronomical clocks4 ,the gridiron pendulum is made of iron and brass1 or zinc1 and is constructed as shown in fig4 #a2 the rod and outer frame1 ,a1 is made of iron1 the two rods inside this of zinc or brass1 ,b ,b4 ,the principle of the instrument is this--brass or zinc contract and expand much more than iron does1 and the short bars of these metals will expand or contract as much as the long bar of iron forming the rod of the pendulum1 so that as this expands and lets the 8bob0 down1 the short bars expand and draw it upwards so that it keeps its place at any temperature2 this requires very accurate adjustment4 ,the mercurial pendulum is shown at fig4 #b2 it is on the same principle1 but is easier to regulate1 and more manageable1 the vessel in the centre being partly filled with mercury1 and forming the weight itself1 and thus as the mercury expands upwards it compensates for the elongation of the rod1 the same as in the gridiron pendulum4 ,the nearer any pendulum is to the centre of the earth the more quickly does it vibrate2 this has been used by scientific men1 to determine by the difference of rate in one placed on a hill1 and another at the bottom of a deep mine1 the amount of matter which constitutes our globe2 indeed by these trials the world may fairly be said to have been weighed6 ,,ploughs4 ,ploughs are instruments used to perform more rapidly what may be effected by the spade1 namely1 the cutting-up and turning-over the surface of the ground so as to destroy all grass and weeds growing in it1 loosen1 so as to expose it to the influence of the air1 and render it fit to receive the seed4 ,illustration3 7 ,,plough47 ,the plough has been in use from the very earliest ages1 and has been but little altered for many centuries2 it is drawn by horses attached to the chain ,a at the end of the 8beam10 and guided by a man holding the 8stilts0 or handles ,b ,b1 the coulter1 ,c1 cuts a perpendicular slice in the ground1 and the 8share0 or 8slade10 ,d1 following1 cuts horizontally1 so as to separate a long piece of earth which the breast or mould-board ,e1 placed obliquely1 turns over on one side2 the plough returning at regular distances1 successive cuttings are thus laid side by side1 forming narrow ridges2 ,f is an additional coulter called the 8skim-coulter10 for removing the surface of the earth1 and is only occasionally used4 ,there are a great many kinds of ploughs1 each suitable to the kind of soil to be ploughed1 whether light and dry or heavy and moist4 ,,harrows4 ,illustration3 ,,harrow4 ,these instruments are used to stir up1 pulverise1 and mix together the earth1 also to tear up any roots that may be left after ploughing1 and to cover up the seed after sowing4 ,the cut represents the usual form of harrow1 having a number of iron spikes or teeth attached to frames of which two or more are united together by chains and attached to a bar1 that the horses may drag them over the surface of the soil4 ,bush-harrows consist of a bundle of brush-wood held together by a pair of frames1 and drawn over the soil when it is very dry and light2 they are used chiefly to cover up the seed after 8drilling40 ,,rollers4 ,illustration3 7 ,,undulated ,,rollers47 ,in clay and other heavy soils1 it is necessary after ploughing to break up the large pieces by means of rollers1 and in light soils to press it together2 for these purposes rollers are used1 either with smooth or undulated surfaces1 as in the figure2 these last form furrows into which the seed falls1 causing it to come up in rows4 ,rollers of a lighter kind are used after mowing to level the surface4 ,,mowing ,,machines4 ,illustration3 ,,fig4 #a4 7 ,,scythe47 ,illustration3 ,,fig4 #b4 7 ,,dray ,,mowing ,,machine47 ,mowing is an operation generally performed by manual labour1 by means of that well-known instrument1 the scythe 7fig4 #a71 which is a long1 flat1 curved blade of steel attached to a handle having a peculiar bend1 and with two short pieces of wood attached1 by which the mower swings it round with a measured sweep1 cutting off the grass almost close to the ground1 walking gradually forward as he mows2 but of late years machines of various kinds have been invented and used for this purpose4 ,fig4 #b represents one which not only mows1 but at the same time rolls the grass1 so as to make it smooth and level4 ,it consists of a heavy iron roller turning a large wheel1 which1 being united to a small one1 causes it to revolve very rapidly4 ,in connection with the small wheel is a series of four spiral knives wound round a cylinder1 which cut off the grass close to the ground1 throwing it up into a box placed to receive it4 ,there are several varieties1 but this is the kind made by ,dray ,co41 ,london1 for mowing short grass1 as in gardens and lawns4 ,those used for cutting long grass for hay1 are exactly similar to the reaping machines4 ,,thrashing-,,machines4 ,illustration3 7 ,,thrashing ,,machine47 ,the operation of thrashing1 performed for ages by means of the 8flail0--two sticks tied together and wielded by the hands1 inflicting heavy blows on the bundle of corn spread on the thrashing-floor1 so as to separate the grains from the ear--is now being rapidly superseded by the thrashing-machine4 ,it is a sort of box having a cylinder inside with an iron wheel at each end united by bars of iron2 this wheel revolves by steam1 causing the bars to fall upon the corn with a gliding motion1 thrashing out the grain1 which falls through and is received below4 ,,reaping ,,machines4 ,illustration3 7 ,,dray7 ,,reaping ,,machine4 ,illustration3 ,,sickle4 ,machines have lately been produced to effect more rapidly1 what has hitherto been done by hand1 with the sickle1 namely1 the reaping of corn4 ,these machines are of various kinds1 but the one that seems most perfect has been patented by ,messrs4 ,dray ,co42 it consists of a heavy wooden frame drawn by a horse1 and having wheels attached1 which on turning round set in motion a line of spear-headed knives2 these knives are made sharp at each side1 to cut both ways4 ,the motion communicated to them is very rapid1 and from side to side1 so as to cause the knives to pass through long narrow openings made to fit them in a series of iron points which are placed one between each knife4 ,this action causes the point and knife to act like the blades of a pair of scissors1 only that the points are fixed and the blades move through them1 cutting off the corn at any distance from the ground that may be required2 at the side furthest from the horse is a point of iron1 having two diverging pieces prolonged from it1 and which pierces the corn and separates the portion to be cut from what is to be cut at the next return of the machine2 for it is drawn up and down1 cutting at each time a belt about four or five feet wide2 when cut1 the corn falls on a platform balanced on its centre1 and capable of being turned so as to incline forwards or backwards4 ,a man sits on the machine with a rake1 and as the platform fills with cut corn1 he pushes it with the rake1 tilting the platform back and delivering the corn behind1 where women attend to bind it up4 ,these machines can reap ten or eleven acres in a day4 ,,drills4 ,illustration3 ,,drill4 ,the drill is used when it is desirable to sow seed in rows at intervals from each other1 so as to give room for the plants to grow1 to free them from weeds and admit air1 light1 and moisture2 it is a machine which contains the seed for sowing1 and at the same time makes a series of furrows to receive it4 ,there are a great many varieties of drills1 but they act upon the same principle1 namely1 that of a cylinder1 taking up and pouring small portions of the seed into funnels so arranged that they shall follow a set of small coulters forming furrows in the ground1 into which the seed falls2 the drill is generally followed by a bush-harrow which covers up the seed4 ,some drills have two compartments1 one for containing manure1 the other for seed2 the manure must be dry and pulverised1 such as ground bones1 ashes1 c41 which arrangement allows the seed and manure to be both drilled together1 so that the manure shall only be applied where it is wanted4 ,the cut represents this machine2 ,a ,a are portions of the cylinders which are turned round by toothed wheels attached to the ordinary wheels of the machine1 and which can be put in or out of gear at any time1 so as to stop the action of the drill2 ,b ,b represent the funnels into which the seed is poured1 and ,c ,c the coulters which cut the furrows for the seed4 ,these coulters are pressed into the ground by means of iron weights attached to the ends of levers joined to them1 and which can be regulated by small chains4 ,,engineering ,,works4 ,,railways4 ,illustration3 7 ,,locomotive ,,and ,,tender47 ,the great advantage of railways over ordinary roads is the diminished friction1 which is produced by the wheels passing over the smooth iron instead of rough stones4 ,it was found when iron rails were first used1 before the introduction of locomotives1 that the horse-power requisite was diminished to one-fortieth2 for instance1 ten horses on a railway could do the work of four hundred on a common road1 this being the case1 and the great power of the locomotive engine being superadded1 there can be no wonder that the difference of the rate of speed between the train and the wagon should be so great4 ,when it has been settled what general direction the railway shall take1 it is then to be determined whether or to what extent the elevations or depressions that may occur can be conveniently overcome1 so that the line may take a straight course1 or whether the road shall go out of the straight line1 and how far to avoid them4 ,the route it should therefore take ought to exactly balance the objections to each extreme1 that is the expense1 c41 of going straight on through hills and over valleys on the one side1 and the increased distance and consequent loss of time which a winding track would cause to the transit on the other4 ,illustration3 ,,fig4 #a4 7 ,,terrain ,,schematic47 ,illustration3 ,,fig4 #b4 7 ,,terrain ,,schematic47 ,illustration3 ,,fig4 #c4 7 ,,rail ,,types47 ,illustration3 ,,fig4 #d4 7 ,,rail 8,,chair407 ,with respect to the 8level0 at which the line should be laid1 a section of the route1 showing all the elevations and depressions1 is first made1 then such a course is chosen that the material produced by cutting through the higher parts shall be just sufficient to form the embankments for filling up the lower parts2 fig4 #a will give some idea of this arrangement4 ,of course a line perfectly level would be the best1 just as would be one perfectly straight2 but as the difficulties of the one must be balanced1 so must those of the other1 and a line as nearly level should be obtained as is consistent with expense4 ,for instance1 suppose ,a and ,b1 fig4 #b1 to be towns to be connected by a line of railway1 and the chief of the intermediate ground to be above their level2 of course it would be very expensive to cut through the whole distance1 as shown at the dotted line a1 this level would therefore be too low2 but if a higher level were taken1 as at the dotted line b1 then only the centre of the distance would have to be cut through1 and the material 7earth1 c47 produced by the cuttings would suffice to fill up the hollows at the ends4 ,these considerations and many others must therefore determine the level at which the railway shall be constructed2 but the line is seldom 7if ever7 on one level from end to end1 nor at one continuous 8gradient0 or slope1 for the course of the line is so arranged as to make as little cutting and filling up as is consistent with a road whose gradients shall never exceed a specified amount1 which must be determined by local circumstances4 ,the excavation and filling up being finished1 the 8trams0 have to be laid2 these are bars of wrought iron about fifteen feet long1 of the form shown at ,a and ,b1 fig4 #c4 ,the most usual form is that marked ,a4 ,they are made of wrought-iron1 passed while hot between rollers cut at their edges into the form required4 ,these trams are laid upon bars of wood called 8sleepers10 at about four feet apart1 and united to them by what are called 8chairs10 which are pieces of cast-iron of the form shown at fig4 #d1 fastened to the sleepers by iron spikes1 and into these the trams1 or 8metals10 as they are called by the workmen are wedged4 ,these bars of iron are laid very evenly and perfectly parallel at a certain distance apart1 which must exactly correspond to the distance between each wheel of a pair belonging to the carriages and engines2 this distance is called the 8gauge10 the wide gauge 7as on the ,great ,western7 is seven feet1 and that called the 8narrow gauge10 is four feet eight-and-a-half inches1 and the space between the lines is of sufficient width to prevent any danger of collision in the trains on passing each other2 they are generally six feet apart4 ,illustration3 ,,fig4 #e4 7 ,,railway ,,switch47 ,illustration3 ,,fig4 #f4 7 ,,turn-,,tables47 ,illustration3 ,,fig4 #g4 7 ,,locomotive ,,on ,,turn-,,table47 ,illustration3 ,,fig4 #h4 7 ,,wheel ,,with ,,flange47 ,illustration3 ,,fig4 #i4 7 ,,carriage ,,buffer47 ,illustration3 ,,fig4 #aj4 7 ,,carriage ,,buffer47 ,as it is necessary that trains should at certain places be 8shunted0 or shifted from one line of rails to another1 particularly at stations where a great many tracks run side by side1 and cross each other to branch off to different parts1 there are arrangements called 8points10 shifted by a lever or 8switch10 so that they shall direct the course of the train1 and cause it to leave the former track and enter upon a new one2 this arrangement may be seen at fig4 #e1 where the points are in the position to direct the engine coming in the direction of the arrow on to the curved line ,a1 and the dotted lines indicate the position into which they would be shifted1 if necessary for the train to go straight on to the line ,b2 this action is effected by moving a lever which shifts the two bars a few inches either way4 ,when an engine or carriage has to be turned on to a track at right angles to the one on which it rests1 or where there is not room for 8shunting10 an apparatus called a 8turn-table0 is used1 which is shown at figs4 #f and #g2 it is a round platform of iron turning on its centre1 and supported by friction rollers at the edge1 having on its surface raised rails in two or more directions1 so that it may be turned round half or quarter distance1 according to the position required4 ,the engines and carriages used to run on railways are of various constructions1 but to a certain extent agree in their chief particulars2 the wheels are fixed to their axles1 so that each pair and the axle which joins them may be considered as one piece4 ,the axle projects a little way beyond the wheel1 and on this part it supports the engine or carriage1 which is wider than the distance from one wheel to its fellow4 ,they are therefore entirely underneath4 ,they are of iron1 made by machinery and have a projecting edge on the inside of the 8tire0 of each1 which is called the 8flange0 7see fig4 #h72 this flange does not run on the rail but within it to prevent the wheels from slipping off4 ,these flanges1 when the pair of wheels and axle are united1 exactly fit in between the rails1 so as to touch the inside of each and form a sort of guide4 ,each carriage has two pairs 7except in a few cases1 where three pairs are used71 the engines have usually three1 and sometimes four pairs4 ,the carriages rest upon powerful springs1 and are moreover furnished with springs to diminish the concussion of one carriage against another2 these last are acted on by a sort of piston-rod1 one of which is placed at each corner of the carriage1 and are called 8buffers0 7figs4 #i and #aj72 they all coincide with each other1 and form a set of springs all along the train1 which greatly reduces the shock which would otherwise be felt when it is stopped4 ,another set of springs is connected with the binding screws which unite each carriage1 and these prevent the sudden jerk which would result from the starting off of a train quite inelastic in its length4 ,the engines used are of that class called high-pressure or non-condensing1 and there are two cylinders and pistons1 which have a stroke of about eighteen inches4 ,the boiler is so contrived that a large quantity of steam shall be rapidly produced2 for this purpose tubes of brass are made to pass side by side from the fireplace through the boiler1 and through these tubes the flame and hot air must go before reaching the funnel1 giving out in its course a great amount of heat to the water and converting it rapidly into steam4 ,the steam from each cylinder passes at each stroke of the piston into the funnel1 assisting to form a draught which draws the flame from the fire through the tubes and increases the fierceness of the combustion4 ,the necessity for two cylinders and pistons is owing to the impossibility of having a fly-wheel1 and as the driving wheels of the engine have to be turned at an equal rate1 the axle has two cranks so placed that the greatest power of one piston is exerted where the other exerts the least 7see 8,steam-engine074 ,illustration3 ,,fig4 #aa4 7 ,,signal ,,tower47 ,illustration3 ,,fig4 #ab4 7 ,,signal ,,tower47 ,illustration3 ,,fig4 #ac4 7 ,,signal ,,lamps47 ,as the trains when going at a considerable speed cannot be suddenly stopped1 it is necessary to have signals placed in certain conspicuous positions1 that the engine driver may begin to stop the train 7when necessary7 in time2 this he effects by what is called a 8break10 a contrivance by which two pieces of wood are made 7by turning a screw7 to grasp firmly each of a pair of wheels1 and so prevent them turning round1 this produces so much friction against the trams that 7after the steam is turned off7 the onward motion of the train is soon stopped4 ,the signals are of three kinds generally1 a red flag to indicate danger1 a green one to caution1 and a white one to show that the way is clear2 these are 7on most occasions7 held by a man and waved to and fro to attract attention1 but there are however a great many occasions for fixed signals1 as at stations and bends in the line where the engine driver can only see a short distance ahead2 these fixed signals consist of tall posts placed where they can be seen at a considerable distance4 ,these posts have an arrangement at the top consisting of a lamp with a 8bull's-eye0 or lens at each side pointing up and down the line1 and a pair of arms capable of being let down into the post1 raised at right angles with it1 or into a position midway between the post and a right angle 7as shown in figs4 #aa and #ab74 ,one side of each arm is painted red1 the other white1 one arm serving for a signal up the line and the other down2 attached to the joint of each arm1 close to the post1 are two iron frames each holding a piece of colored glass1 one red the other green1 and so arranged that when the arm is at right angles to the post1 the red glass is before the lamp and when the arm is let half way down the green glass comes in front of the lamp 7fig4 #ac71 thus the same action serves both for day and night signals4 ,when the arm showing the red side projects in a horizontal direction1 it indicates 7in the day7 8danger10 and so does the red light at night2 when the arm is let down half way1 it shows that caution is required1 and the green glass then before the lamp shows the same signal at night2 when the arm is let quite down out of sight1 it shows safety1 and so does the white light of the lamp thus freed from both screens of colored glass4 ,illustration3 ,,fig4 #ad4 7 ,,engine ,,whistle47 ,each engine is provided with a whistle 7fig4 #ad7 blown by steam turned on from the boiler1 which is used as a signal at any particular time1 especially in tunnels or when there is a fog2 there is also an arrangement by which each engine presses on a lever at the side of the tram as it passes1 and causes a bell to ring at the station1 to announce its approach1 when about a quarter of a mile off4 ,in some cases1 as in foggy weather1 when the usual signals cannot be seen1 a packet of fulminating powder is placed on the rail1 and this being exploded by the wheel of the engine as it passes over it1 gives notice of its approach1 c4 ,there are other signals1 but these are the chief4 ,,electric ,,telegraphs4 ,illustration3 7 ,,electric ,,telegraph47 ,the power of transmitting messages to any distance or place to which a wire can be carried1 and in a space of time too small to be reckoned1 is without doubt one of the most wonderful inventions ever carried out by men's hands4 ,although the signals are carried from place to place with a rapidity almost incredible1 yet the electric fluid travels at a certain1 although marvellously rapid rate4 ,it is thought that light and the electric fluid both travel at the same rate1 namely1 #aib1jjj miles in a second1 and if so1 a message might be sent round the world 7were it possible to carry on a wire7 thrice in that small space of time4 ,illustration3 ,,fig4 #a4 7 ,,acid ,,battery ,,cell47 ,illustration3 ,,fig4 #b4 7 ,,battery ,,series47 ,illustration3 ,,fig4 #c4 7 ,,grounding ,,effect47 ,the construction of the electric telegraph is pretty much the same everywhere1 only that modifications of the same agent are used in different countries1 and different signals formed2 but whether this agent or influence is obtained from magnetic or galvanic sources1 the result is exactly the same4 ,when a pair of metallic plates are immersed in a fluid which acts chemically more rapidly on the one than the other1 and a wire connects the upper parts of these plates1 this wonderful agency is set in motion1 and circulates from the one plate to the other 7fig4 #a74 ,this arrangement may be best shown by using one plate of zinc and the other of copper1 and a dilute solution of sulphuric acid for the liquid2 this1 however1 produces by far too little of the agent to be used on a telegraphic line1 there are therefore combinations of such pairs of plates so arranged that the power of one pair shall be added to the next in such a way that at the end of the series 7called a 8battery07 there shall be a great increase of the power accumulated--this arrangement is shown in fig4 #b4 ,now 7if the power be sufficient7 it does not signify what length of wire there may be between the two ends of this arrangement or 8battery10 whether the ends be connected by a few feet of wire1 or as many hundred miles--the electricity passes instantaneously from one end to the other2 and furthermore1 it has been found in practice1 that this electrical influence can be transmitted through the earth in one direction if sent by a wire in the other2 for instance1 if a wire from one end of the battery be carried on from ,london to ,liverpool2 instead of having another from ,liverpool to ,london1 to connect the two ends of the battery1 it is found to answer the same purpose if the end of the wire at ,liverpool be fastened to a plate of metal buried beneath the surface of the earth and the other end of the battery at ,london1 furnished with a similar plate also buried4 ,in this arrangement1 the electricity will pass beneath the surface of the earth from ,liverpool to ,london1 and through the wire from ,london to ,liverpool1 thus completing the circuit4 ,the end from which the electricity passes is called the 8positive electrode10 that to which it returns the 8negative electrode40 ,fig4 #c will show this arrangement4 ,illustration3 ,,fig4 #d4 7 ,,electro-,,magnet47 ,illustration3 ,,fig4 #e4 7 ,,electro-,,magnet ,,turned ,,on47 ,illustration3 ,,fig4 #f4 7 ,,angled ,,view ,,of ,,electro-,,magnet47 ,illustration3 ,,fig4 #g4 7 ,,eight ,,needle ,,positions47 ,illustration3 ,,fig4 #h4 7 ,,telegraph ,,poles47 ,illustration3 ,,fig4 #i4 7 ,,wire ,,insulator47 ,illustration3 ,,fig4 #aj4 7 ,,six-,,wire ,,cable47 ,if a bar-magnet be suspended on a pivot so that it may turn freely1 it will 7as is well known7 turn with one end to the north1 which is owing to a current of natural electricity passing round the earth in the direction of east and west1 the magnet crossing the current at a right angle2 and if a coil of wire coated with silk 7to keep one part of the coil from another7 be placed round1 above and below the long axis of a bar of steel as shown at fig4 #d1 and a current of electricity passed through this wire1 the steel becomes a magnet and will take a direction similar to the natural magnet1 more or less at right angles to this coil1 as in fig4 #e1 according to the intensity of the current2 and the instant this electrical current is stopped it will resume its former direction4 ,this fact has been made use of to form the principal feature of all ,english telegraphs2 in the telegraph such a needle is mounted in an upright position1 and instead of its tendency to turn to the north1 a tendency to maintain the upright position is given to it by having one of the arms of the magnet a little heavier than the other2 such a magnet having a coil of wire surrounding it4 ,when the electric current passes through the coil1 it will turn out of the upright position to either one side or the other1 according to the direction of the current1 from its tendency to assume a position at an angle to the current 7fig4 #f72 if the current be stopped even for an instant1 then the needle or magnet will again assume its upright position4 ,the pivot of this magnet is brought forward and has on its front part another needle1 which being on the same pivot turns with it2 this is visible on the outside of the apparatus1 and is looked at to ascertain the movement of the one within4 ,there is also an arrangement called a 8commutator10 so contrived1 that by moving a handle to the right or left1 a connection shall be made with either end of the battery1 and thereby cause the direction of the current and needle to be changed at pleasure2 also by moving the handle into an upright position the current shall be stopped2 and finally1 by a third movement1 a bell shall be rung4 ,now1 as has already been explained1 when the current goes in one direction1 the magnetic needle is deflected in that direction2 and when the current is reversed the position of the needle is also reversed1 and when the current is cut off the needle will resume its perpendicular position4 ,if two such needles and two such handles be at each station1 when the handles at one station are moved1 the needles at the other station will take on a similar movement2 and when the handles at that station are moved1 the needles at the first station will be moved to correspond4 ,this constitutes the system of communication kept up by the electric telegraphs in ,england2 but it remains to be shown how all the letters of the alphabet1 the numerals1 c41 can be represented by the movements of the two handles4 ,these handles can be placed in eight positions 7besides the upright one7 by a single movement of each hand1 as may be seen in fig4 #g2 and these eight signals if repeated1 or made twice in rapid succession will make eight more1 and by being repeated three times will constitute a third eight1 making twenty-four2 finally1 by a rapid motion right and left1 they may be caused to signify a fourth eight1 or thirty-two signals1 which are found to be sufficient for every purpose1 and by practice may be both produced and read off with facility4 ,before a message is about to be delivered the commutator is so placed as to ring a bell1 which is done by the same arrangement as in a common alarm-clock1 but the action is set in motion by a peculiar contrivance1 which depends upon the property a bar of soft iron has of becoming magnetic when a wire is wound round it and a current of electricity passed through this wire2 this magnetic property exists only as long as the current passes1 and stops the instant it is cut off4 ,the catch of the alarm is disengaged by the movement of a bar of iron being drawn to the magnet while the current passes1 and forced back again by a spring when it is stopped1 thus setting in action the mechanism of the alarm1 or in some cases there is a simple contrivance for causing a rapid flow and stoppage of the electricity1 so that the bar is alternately attracted by the magnet and released by the spring1 and this motion of the bar rings the bell as long as it is continued4 ,the bell is always rung to give notice that a message is about to be sent1 and at the station where the bell rings1 the bell at the former station is rung in return1 to show that they are prepared to receive the message2 the message is then spelt letter by letter1 by moving the handles into the proper positions1 and as the message is being sent1 the eye is kept on the dials having the needles which will communicate any message in return from the station to which the message is being sent1 such as 8repeat10 8not understood10 c41 c41 for which certain single signs are made and recognised4 ,the wires which convey the electricity from station to station1 are made of galvanized iron 7iron coated with zinc71 and must be kept from all communication with the earth by some substance incapable of conducting it2 they are therefore stretched between wooden poles 7fig4 #h71 and rest upon sockets or supports of glass or glazed earthenware1 which are both substances incapable of conducting the electricity to the earth 7fig4 #i74 ,in certain localities1 as in towns1 the wires are coated with gutta percha 7another non-conductor71 and laid side by side in a tube under ground2 this is also done in the longer tunnels4 ,in the cables which conduct the electric power along the bottom of the sea as from ,dover to ,calais2 the wires are first coated with gutta percha1 then bound with yarn soaked in tar1 and finally coated with galvanized iron wires wound round spirally like the strands of a rope 7fig4 #aj71 the whole forming a cable which is coiled up in the hold of a vessel1 and let out as the vessel crosses from one side to the other2 in this way the cable is deposited on the bed of the sea or channel1 forming an electrical connection from country to country4 ,these cables are made in one piece by machinery4 ,that from ,dover to ,calais is twenty-five miles long1 contains four copper conducting wires1 and weighs about #age tons2 that from ,dover to ,ostend contains six conducting wires1 is seventy miles long1 weighs nearly #ejj tons1 and cost about #cj1jjj2 its structure 7the real size7 is shown at fig4 #aj4 ,illustration3 ,,electric ,,time ,,ball1 ,,charing ,,cross4 ,the electric cable now constructed to be laid down between ,ireland and ,america1 is composed of seven small copper wires twisted into one1 and surrounded by gutta percha2 this is then surrounded by eighteen small wire-ropes1 each composed of seven small wires twisted together1 the whole being in its section not larger than a four-penny-piece2 #bjjj miles of this cable are now ready to be laid down4 ,a plan was some time ago put in practice by which the correct time could be kept at various places by electric communication with the time at ,greenwich2 a clock thus regulated1 is situated at ,charing ,cross1 and a ball placed at the top of the electric telegraph station there1 is caused by the same means to fall exactly at one o'clock4 ,a contrivance has of late been patented to work the electric telegraph by steam1 and the following account of it is extracted from the 8,times30-- 8,a series of gutta percha bands1 about six inches wide and a quarter of an inch thick1 are coiled on wheels on drums arranged for the purpose4 ,these bands are studded down both sides with a single row of holes at short intervals apart4 ,when a message is to be sent the clerks wind off these bands1 inserting in the holes small brass pins1 which1 according to their combinations in twos or threes 7with blank holes between71 represent certain words or letters4 ,in this manner the message is1 as it were1 8set up0 in the bands with great rapidity1 and if the number of bands employed is sufficiently large--say as numerous as the compositors employed in a large printing-office--messages equal in length to five or six columns of this journal could be set up and ready for transmission in the course of a single hour4 ,of course this operation in no respect interferes with the telegraph wire itself1 which continues free for use until the bands of messages are actually being despatched4 ,the gutta percha bands when full are removed to the instrument-room1 a most simple appliance preventing any derangement or falling out of the pins while being moved about4 ,in the instrument-room the bands are connected with ordinary steam machinery1 by which they are drawn in regular order with the utmost rapidity between the charged poles of an electrical machine in such a manner that1 during the moment of each pin's passing1 it forms electrical communication between the instrument and the telegraph1 and a signal is transmitted to the other end of the wire1 where the spark perforates a paper and records the message4 ,the only limit to the rapidity of the operation is the rate at which the bands can be drawn1 since the electrical contact of each pin1 even for the #bjjth part of a second1 is more than sufficient to transmit a word or signal from ,london and register it in ,america4 ,of course1 as the message is recorded 7we will say in ,america7 with the same rapidity as that with which it is transmitted from ,london1 a number of reading clerks will be requisite in order to translate it1 by dividing it into small portions1 with almost as much facility as it has been sent40 ,,roads4 ,illustration3 7 ,,train ,,bridge ,,over ,,road47 ,roads1 which were formerly of the utmost importance as the only means of communication between distant places1 and on which an enormous amount of labour and capital have been expended1 are now becoming rapidly subordinate to railways2 however this may be1 it is quite clear that roads can never be superseded by the latter4 ,the numerous streets of great towns are so many short roads1 and on some of them the amount of traffic is so very great1 that the utmost skill of the engineer is required to resist the consequent wear and tear4 ,the ,roman roads1 which have been the means of civilisation to the greater part of ,europe1 were constructed in a very solid and durable manner1 by first laying down a layer of rough stone set in cement1 and upon this1 stones either squared or nicely fitted together and also cemented2 the whole formed a solid mass of masonry1 not unlike the wall of an old castle laid horizontally4 ,basalt 7a volcanic product7 was the stone used for this purpose1 where it could be procured4 ,these roads were generally raised above the surrounding ground1 but excavations1 bridges1 and tunnels were made where these were found necessary to continue the road in a direct course4 ,illustration3 7 ,,labourers ,,ramming ,,surface47 ,roads are now generally made in a less careful manner1 and the same observations as to course and levelling will apply to them1 that are made on these subjects in the article 8,railways10 only that less cutting and filling up are required1 as the gradients on common roads are allowable of much greater steepness than on railways2 one in twenty-five is however about the greatest declivity that should be made1 although old roads exist with slopes much greater4 ,the surface of a road should be slightly arched and a drain made on each side1 that pools of water may not collect on its surface and soften it so that it will work into holes4 ,ordinary roads are made by laying down a stratum of broken granite or other hard stone a few inches deep1 each piece being of about half a pound weight1 when this first layer is worked in by traffic1 a second is laid1 and so on till the surface has become quite firm and level1 but in the streets of towns more care is required4 ,in the suburbs of ,london1 the usual plan is1 to lay a deep stratum of rubbish1 consisting of broken bricks1 pottery and oyster-shells 7obtained from the dust-bins of ,london7 nearly a foot in thickness1 and on this1 broken stone or shingle 7consisting of pebble stones7 is laid in repeated layers as it consolidates1 but in the streets having more traffic the roadway is made by a foundation of 8concrete10 consisting of coarse gravel and lime made into a sort of paste1 which sets into a hard cement in a day or two2 on this foundation 7which is carefully smoothed on the surface7 is laid a paving of squared granite blocks1 placed carefully side by side either in lines at right angles to the road or else diagonally4 ,when these are all laid down and rammed to a perfectly even surface1 a mixture of quick lime and sand is made into a thin paste with water1 poured on and swept all over the surface with brooms1 so as to fill up the interstices and cement the blocks of granite firmly together4 ,in ,london the roadways are always made arched1 so that the centre is a few inches higher than the sides1 and a gutter or drain is placed on either side between it and the pavements which run on each side1 but in many towns in the country1 and on the continent1 the gutter is placed in the middle of the road and each side made to slope slightly towards it4 ,,bridges4 ,the earliest efforts of the civil engineer were in all probability directed to the construction of roads1 but it would be evident that unless they could be made to cross rivers and water-courses1 they could continue but a short distance in any required direction4 ,bridges of some sort must therefore be constructed2 small brooks were doubtless bridged over with timber laid across them1 and 8fords0 or shallow parts of rivers taken advantage of when the stream was too wide to be spanned in this way4 ,that these fords were once very numerous in ,england1 is shown by the constant recurrence of such names as ,stratford1 ,brentford1 c41 and indeed fords are now in use in many places where the stream is shallow1 and the traffic too little to pay for constructing a bridge4 ,the next improvement in all probability consisted in placing stones in the fords to enable passengers to step from one to the next1 and cross the stream dry-footed1 which were called 8stepping stones20 but the earliest bridges properly so called1 were probably stones piled upon each other and united by beams of timber4 ,illustration3 ,,viaduct4 ,the ,chinese1 ,romans1 and several other nations were acquainted with the use and proper mode of constructing bridges1 many centuries ago1 when no such works had been attempted in ,england4 ,the materials chiefly now in use for bridges are stone1 brick1 iron1 and wood1 and by far the greatest number1 till within the last half century1 were constructed of stone1 but iron seems to be rapidly taking its place1 especially since the mode of constructing suspension bridges has been more perfected4 ,there are several ways of forming the foundation for the piers1 or those parts on which the bridge rests4 ,old ,london bridge and many others of considerable size were based upon 8piles10 these piles consist of great pieces of timber pointed at one end and driven deep down into the bed of the river close together1 so as to form a solid mass on the top of which the stones for the piers were laid2 these piles have been found scarcely altered after several centuries of immersion in the mud1 but at the parts exposed to the action of the water they soon become decayed and eaten away by its inhabitants4 ,for many bridges1 when there is good foundation1 the stonework is laid at once on the bed of the river1 but in order that this may be got at1 a double ring of piles is driven close together around the part where the pier is to be built2 these piles are of a flat form1 and the two rows inclose a space of about a foot between them1 which space is filled with clay1 well rammed in1 and the water within the barrier pumped out1 this forms what is called a 8coffer-dam10 and is an expensive proceeding4 ,the bottom of the river thus exposed can be built upon in the usual way4 ,another way of forming a foundation for piers consists in lowering large wooden frames or boxes filled with concrete which hardens and forms a solid basis1 these are called 8cassons40 ,wooden bridges are now seldom made of any great size1 but are very numerous in country places for crossing narrow streams1 on account of their cheapness and the facility with which they can be constructed4 ,bridges of brick are not much used1 but 8viaducts0 of this material often occur in the lines of railways1 and very handsome arches of brick-work are used to span streets in towns where railways pass4 ,iron girder bridges also1 are frequently employed for this purpose2 they are made with girders of wrought or cast iron which generally pass in a straight line over the roadway from pier to pier4 ,some of them are made of iron-plate rivetted together1 while others are strong girders of cast iron having small arches of brick-work built on them1 running the length of the girders and resting upon ridges in them1 so as to fill up the space between each girder4 ,illustration3 ,,the ,,britannia ,,tubular ,,bridge4 ,iron bridges are of almost every form and construction conceivable2 some are tubes of iron-plate1 as the ,britannia ,bridge1 rivetted together2 some of solid cast iron work as ,southwark ,bridge1 others called suspension bridges are hung by rods of wrought iron1 from large chains suspended from pier to pier1 as ,hungerford ,bridge4 ,in many places bridges of boats are used2 the boats are moored to the river's-bed and have timber-work connecting them4 ,another kind1 which can hardly lay claim to the name of bridge1 called the 8floating-bridge10 is used for the conveyance of carts1 horses1 passengers1 or merchandise1 from one side of a river to the other4 ,it consists of a sort of platform guided by chains laid down for the purpose1 which pass over wheels or drums on the side of the bridge4 ,the motive power necessary for turning these wheels1 is supplied by a steam-engine within the structure itself4 ,,tunnels4 ,illustration3 7 ,,railroad ,,tunnel47 ,tunnels are underground passages made for the purpose of continuing roads1 railways1 or canals through hills or elevated parts of the ground4 ,in slight elevations 8cuttings0 are generally made1 and it becomes a question of expediency for the engineer as to which of the two shall be chosen1 as there will be a much greater quantity of earth to remove from a deep cutting than from a tunnel2 in fact1 the question is often at once determined by the demand for this material1 for if it should so happen that the level of the road is such1 that many or large embankments are required1 the earth taken from the cuttings will be wanted to construct them4 ,as a general rule1 tunnels are only made where a hill has to be penetrated which is too high to be cut through2 another object sought by tunnelling is to cause the road to pass beneath a canal1 river1 buildings1 or roads1 where the level of the road or railway is far below them4 ,the ,thames ,tunnel is the most remarkable example of this kind of work4 ,tunnels were constructed by the ancient ,greeks and ,romans1 chiefly for the purpose of forming aqueducts1 and for draining lakes4 ,a few years back1 tunnels were not very frequently undertaken1 those that were made being chiefly on the lines of canals1 but they are now far more numerous1 on account of the great number of railways1 on which they frequently occur4 ,before a tunnel is undertaken1 the nature of the soil should be thoroughly examined by means of 8borings10 sunk down to the intended level1 some soils being much less favourable than others for this purpose4 ,quicksand1 or sand percolated by water1 is one of the greatest impediments to tunnelling1 while rock 7contrary to what would at first be thought7 is one of the least1 as in this case there is no occasion to line the tunnel with brickwork1 which more than saves the extra expense of excavation1 as that can be rapidly done by blasting1 where it is too hard to dig1 while in the former case the difficulty of draining off the water1 and the cost of brickwork of sufficient solidity to support such loose earth1 often prevent the undertaking4 ,tunnels of great length are sometimes begun at several different parts by means of shafts sunk down to the required level1 and each made to unite into one1 but this depends upon where the earth is to be deposited2 on railways it is common that the 8level0 is so chosen that the earth from tunnels and cuttings is always wanted to fill up hollows in their immediate vicinity 7see 8,railways071 and when this is the case a series of 8trucks0 drawn by an engine on temporary tramways remove the earth from the tunnel as it progresses1 to the next embankment1 both works proceeding at the same time4 ,when a small portion of the tunnel is excavated1 the casing of brickwork is begun from the mouth of it1 and continued a small piece at a time1 following closely the excavation4 ,the brickwork is generally begun at each side1 and carried up to the height at which the arch springs2 an inverted arch is then constructed from one side to the other to form the floor1 and 8centreings0 resting upon uprights are placed1 to 8turn0 the arch upon4 ,these centreings are only about two feet deep1 and span the arch from side to side2 the men work with their backs to the part being excavated1 and are able to reach across the narrow centreing to lay the bricks4 ,when completed all round1 and the spaces between the brickwork of the arch and the surface of the excavation filled up with earth1 the centreing is shifted further in and a fresh ring of brickwork commenced1 the excavation going on at the same time4 ,in many tunnels1 large perpendicular shafts are sunk down for the purposes of ventilation and lighting4 ,,drains4 ,illustration3 ,,drain 7 ,,diagram74 ,illustration3 ,,drain-,,pipes ,,and ,,tiles4 ,drains are constructed for the purpose of carrying off from the surface of the ground all superfluous fluid1 whether it may arise from want of a proper exit for the rain1 from springs rising in the ground to be drained1 or from water coming from some higher level4 ,drains are made in towns to carry off the rain from the surface1 and all liquid refuse from the houses4 ,when the surface of any portion of land has to be drained of its accumulated water1 where the soil is of an impervious nature1 like clay1 it is usual to cut deep furrows from the higher to the lower parts and fill these up with gravel stones or brushwood2 the moisture which collects in these is made to flow into the lowest part1 and there form a pond1 from which it evaporates as fast as the drains supply it2 or if the quantity be too great1 a main drain or ditch carries it onwards to some stream or river4 ,the furrows before being filled up with any porous substance are often laid down with 8drain-tiles20 tiles bent into the form of half a cylinder1 and placed with two edges on a flat tile at the bottom of the drain1 or pieces of tubing made of tile4 ,the water finds its way readily into these through the crevices4 ,in some cases1 water can be kept from flowing over lands and forming marshes1 by embankments4 ,these are more especially useful in land lying below the level of rivers and lakes2 immense tracts are thus preserved in ,holland4 ,when these embankments are very extensive1 there is a constant filtration of the water through them2 drains are therefore constructed to collect it into certain spots1 and mills erected to pump it over the banks4 ,these are usually small windmills1 working a large wooden screw in a cylindrical barrel1 causing the water to rise up the cylinder into a trough1 from which it is poured over the embankment2 these mills require little or no attention1 and work at all times when the wind blows4 ,when water accumulates in valleys lying above the sea1 deep cuttings or even tunnels may be necessary to carry off the water2 at ,neufchtel in ,switzerland1 very extensive tracts of land have been reclaimed1 by boring a tunnel through the surrounding hills1 and thus letting off the water from the lakes formed by the rain4 ,sometimes land may be drained by boring through the clay or other impervious soil1 down to a porous stratum1 such as sand or gravel4 ,a knowledge of the structure of the whole district is necessary to determine whether this is likely to be of service or not4 ,by boring deep pits in the drains cut in peat mosses1 the weight of the mosses will cause the water to be squeezed out1 which rising in these holes flows off by the drain1 producing the same effect as if it were cut to the depth of the pits4 ,drains are frequently made by means of narrow curved spades1 but the draining plough effects the purpose more rapidly1 and is very generally used4 ,the drainage of ,london and other large towns consists of small drains from each house1 made of earthenware tubes leading to a sewer of brickwork1 running along each street and uniting with larger ones4 ,the question of effectually draining ,london is a very difficult one1 schemes of various kinds being at this time propounded1 which would cost several millions of pounds to put into practice2 at present all the sewage runs into the river ,thames1 and it is a matter of serious importance to obviate this1 by carrying it off to some other place4 ,,artesian ,,wells4 ,illustration3 ,,fig4 #a4 7 ,,bent ,,tube47 ,illustration3 ,,fig4 #b4 7 ,,tapped ,,bent ,,tube47 ,illustration3 ,,fig4 #c4 7 ,,artesian ,,basin47 ,illustration3 ,,fig4 #d4 7 ,,drill ,,bit47 ,the construction of artesian wells depends upon the fact that water1 being at liberty to flow1 will always sink to a level2 by which it is meant that the parts which are highest press upon those that are lower1 and tend to raise them1 the higher parts sinking in the same proportion that the lower parts are elevated2 this continues until both are upon a level4 ,suppose a bent glass tube of the form of fig4 #a1 be partly filled with water1 the surfaces of the water in both arms of the tube will each be upon a level with the other2 suppose now another such tube to have a small hole at ,a1 the water sinking in each arm will force out a jet of water1 and if a tube be inserted into this hole it will represent an artesian well1 and the water will rise in it till all three are on a level 7fig4 #b74 ,instead of these tubes there is a layer of some porous material1 as gravel1 at some distance beneath the surface of the earth1 rising at each end and forming a sort of basin 7fig4 #c71 which is bounded above and below by some impervious substance as clay or stone2 the well being sunk at any part 7as at a1 b1 or c7 below the level of the gravel1 where it forms the surface of the earth1 must cut through the upper stratum of clay or stone1 and thus form a tube into the porous gravel which holds the water2 this water is obtained from the rain1 which1 falling on the surface of the earth1 drains through the gravel and fills its lower part4 ,the water will rise in the bore at a height according to circumstances1 if the gravel at each side of the bore rises to higher ground1 a jet of water will be forced out1 if not so high1 the well will only partly fill1 and so on4 ,artesian wells are sunk or bored by means of instruments screwing on to the end of a set of iron rods each screwing into the end of the other as shown in fig4 #d4 ,the first piece is generally a sort of gouge 7a7 two or three inches wide1 and so made as to bring up a cylindrical piece of earth when forced in and screwed round1 the weight of the rods after a few pieces are added is sufficient to force the gouge into the earth1 except in stony places1 when a sort of 8pick0 is used4 ,the official report of ,general ,desvaux on the artesian borings executed in the ,desert of ,zahara of the province of ,constantine1 in #ahef-g1 states1 8that a spring affording #djaj quarts of water per minute1 was the result of one of the borings1 and that others affording #ce1 #abj1 and #d1cjj quarts respectively were successively completed40 ,and he goes on to say3 8,when the shouts of the soldiers announced the gush1 the ,arabs sprang in crowds to the spot1 laving themselves in the welcome abundance1 into which mothers dipped their children2 while the old ,sheik fell upon his knees and wept1 returning thanks to ,allah and the ,french4 ,at ,oum ,thiour a well sunk to the depth of #agj metres and yielding #ahj quarts a minute was at once taken as the centre of a settlement by a portion of a previously nomadic tribe4444 ,as soon as the water appeared they began the construction of a village1 the plantation of #a1bjj date trees1 and entirely renounced their wandering existence40 ,according to ,general ,desvaux's report1 these artesian wells are likely to have a most important influence on ,arab life1 and greatly to subdue the roving propensities of many of the tribes4 ,,mines4 ,mines are excavations made in the earth for the purpose of raising the various minerals which exist below its surface1 such as coal1 rock-salt1 and the various ores from which metals are extracted 7see 8,smelting074 ,mines consist of those which contain minerals that lie in strata parallel 7or nearly so7 to the surface of the earth1 as coal1 rock-salt1 or iron-stone1 and those containing the ores and minerals which are imbedded in seams or fissures of the primitive rocks1 and are nearly perpendicular to the surface4 ,of the former kind1 coal-mines form the chief examples4 ,when indications of coal are discovered1 a 8boring0 is commenced to ascertain its existence1 and the depth at which it is placed below the surface4 ,each piece of earth raised by the boring-tools is placed one beside the other1 in the exact order in which they are raised1 so as to show the kind of earth being bored through1 and the thickness of each strata between the surface of the earth and the seam of coal2 and it sometimes happens that the boring is stopped on arriving at certain kinds of rock--the old red sandstone1 for example--for it would be useless to continue boring beyond this1 no coal ever existing below it4 ,when coal is found1 and its quality and the thickness of the seam ascertained to be such as to warrant further expense1 a shaft is dug down of some eight or ten feet diameter1 cased with brickwork or wood to prevent the falling-in of its sides1 and in some cases powerful machinery has to be erected to pump out the water which flows in4 ,on reaching the coal1 galleries--called 8gates10 or 8bords0--are dug in it in opposite directions1 forming one long straight passage1 and from this other smaller ones1 called 8headways10 are dug1 at right angles1 to the depth of about twenty-four feet1 and from these other 8gates0 are carried parallel with the first1 forming a series of roadways joined by short passages1 and having squares of coal between them2 the height of all these passages is determined by the thickness of the seam of coal1 usually from three to ten feet4 ,the great masses of coal forming the squares between these passages are gradually dug away 7as far as can be done with safety7 and the gates continued onwards1 but before long the ventilation becomes impeded1 and the air foul and dangerous from 8fire-damp0 7carburetted hydrogen7 or 8choke-damp0 7carbonic acid71 gases which are given off from the fissures in the coal4 ,it is therefore necessary to produce a continuous current of fresh air in every part of the mine1 which is done by sinking another shaft at the furthest part of the mine and keeping a large fire burning at its mouth1 over which a tall shaft is generally erected1 from which a column of light air ascends1 drawing fresh air down the other shaft and through every part of the mine1 to supply this 8up-cast0 shaft1 as it is called4 ,this supply of fresh air is economised and regulated by doors or valves1 so placed that any part requiring extra ventilation can obtain it at any moment by shutting these doors and letting the whole current go through that particular part4 ,the removal of coal is effected partly by digging with the 8pick10 and partly by blasting with gunpowder2 a large square mass is cut all round1 and a charge of powder fired behind it1 so as to bring down at once sixty or eighty tons of coal1 which is brought along the gates on 8trams0 to the bottom of the shaft1 where 8corves0 or baskets filled with it are drawn up to the 8pit's-mouth0 by steam machinery1 one corve ascending full while another is descending empty4 ,the mines from which most minerals1 such as sulphuret of lead 7galena7 or of copper1 are drawn1 belong to the second class1 or those whose shafts 8cut0 the vein of mineral at a very acute angle4 ,when the existence of the required mineral and its 8dip0 or inclination is ascertained1 a shaft is sunk so as to cut its upper surface1 and then carried through it1 cross-cuts being formed on to the vein1 and 8levels0 or galleries right and left in the direction of the vein4 ,from these levels 8winzes0 or small shafts are cut at intervals from one level to that below it1 thus leaving square portions of the mineral vein to be explored1 which is done by digging away the roof or upper part1 so that the rubbish and ore falls down1 when it is sorted and carried away4 ,,ships4 ,illustration3 ,,building ,,slips4 ,illustration3 ,,fig4 #a4 7 ,,keel ,,construction47 ,illustration3 ,,fig4 #b4 7 ,,treenail47 ,the first part of a ship 8laid down0 is the 8keel20 this is the projection which runs along the whole length and forms the lowest part of the ship4 ,the ship is built in what is called the 8building slip10 which slopes towards the water2 in this 8slip0 a row of oaken blocks are placed at a few feet apart1 and about three feet high1 on which the keel is laid2 these blocks are for the purpose of allowing the workmen to cross from side to side below the keel and to form a foundation for the ship to rest on4 ,in fig4 #a1 ,a is this arrangement of blocks1 ,c the keel1 at the hinder part of which is the 8dead wood10 or the timbers filling up the space between the keel and the curved bottom of the ship1 which is more curved than the keel1 and very much so towards the 8stern0 or hindermost part4 ,across the keel are laid the 8floor-timbers0 or 8ribs10 ,b1 which are curved timbers laid at right angles to the keel and passing outwards and upwards in the exact curve which the sides of the ship are to assume2 these are too curved and too long to be of one piece1 others1 therefore1 are added1 and joined end to end with the first by wooden bolts or 8dowels20 these curved timbers are cut to a pattern1 chalked on the floor of the 8mould-loft40 ,the ribs as they cross the keel are bound to it by a piece of strong timber running along inside of or above them1 but parallel to1 and exactly over it1 which is called the 8keelson10 and is bolted to the keel through the centre of each lower piece of the ribs or floor-timbers2 it is shown at ,d1 fig4 #a4 ,in large ships there are three of these keelsons1 running side by side1 and forming a strong support to the masts1 which rest upon them4 ,at each end of the keel a bar of timber rises1 the hindermost being called the 8stern-post10 and that in front the 8stem-post0 7marked ,e and ,f in fig4 #a74 ,across the ribs on the outside and parallel to the keel1 are laid the 8planks10 which are boards of oak of from two to six inches thick1 laid close together and touching at their edges2 these are fastened to the ribs by plugs of oak1 called 8treenails10 going right through the planks and ribs1 and wedged at each end 7fig4 #b74 ,in large ships1 similar planks line the inner side of the ribs1 and oblique or diagonal braces are also sometimes used1 to strengthen the ship and keep it from curving or 8arching0 when in the water4 ,illustration3 ,,fig4 #c4 7 ,,cross-,,section ,,of ,,hull47 ,illustration3 ,,mast ,,house4 ,the masts of a 8ship0 are three in number1 a 8schooner0 has two1 and a 8sloop0 but one4 ,these masts pass right down through the decks1 and rest upon the keelson4 ,in small vessels each division is made of one piece1 but in larger ships they are made up of a central piece1 with others fastened round it so as to enlarge and strengthen it4 ,the first or lower division of the central mast is called the 8main0 mast1 and that above it the 8maintop0 mast2 the fore mast is divided into 8fore0 mast and 8foretop0 mast1 and the after mast is called the 8mizen0 and 8mizentop0 mast1 and the pieces above these the 8foretop gallant0 mast1 8maintop gallant0 mast1 and 8mizentop gallant0 mast4 ,these masts are made1 and raised by cranes in a building called a mast-house1 and placed in the right position in the ship floating beneath4 ,the outside of ships1 as high as the 8water-line10 is covered with a sheathing of copper to defend it from the action of the 8worm0 7,teredo navalis71 which bores into and destroys the wood exposed to its ravages2 the copper also presents a smooth surface to the water1 and facilitates the motion of the vessel4 ,at the stern of the ship is placed the 8rudder10 a wooden construction turning like a door on fastenings1 and which1 by being moved on one side1 presents a greater amount of resistance to the water1 and consequently tends to turn the stern of the ship away from that side1 thus altering its course4 ,the decks of a ship are like the floors of a house1 running across from side to side1 and supported on strong beams bolted into the sides2 they are slightly arched1 to increase their strength1 as they have in ships of war to support the weight of the guns1 c4 ,a section of the decks and other parts of a ship is shown at fig4 #c4 where the general figure and the different parts described may be seen2 the section is through the middle1 from side to side4 ,most ships of any considerable size carry several boats with them1 either on deck or suspended between the masts1 to serve as a means of escape in case of fire1 or any other accident requiring the crew to leave the ship1 also as a means of keeping up communication with the shore4 ,ships of war are named according to the number of guns they carry1 as a seventy-four1 a hundred-and-twenty-gun ship1 c4 ,illustration3 ,,repairing ,,dock4 ,when ships have to be repaired they are brought into the repairing dock1 which has a pair of gates shutting it off from the river2 when they are closed 7at low water7 the water is pumped out from the dock1 and the repairs done2 when finished the water is let in1 and the ship floats out4 ,in small vessels it is sometimes sufficient to haul them on shore at high tide1 so that when the tide is down they may be left high and dry and repaired1 and when the tide is at the highest1 hauled off again4 ,steam ships are constructed to be propelled either by paddle wheels having flat boards fixed to their circumferences1 which on being turned round1 take a great hold in the water1 and so cause the motion of the ship2 or by the screw-propeller1 which has been described4 ,illustration3 ,,paddle ,,and ,,sailing ,,ship4 ,illustration3 ,,breaking ,,up4 ,the iron ships1 which of late have almost superseded those of wood1 are made of plates of wrought iron1 rolled1 while red hot1 between rollers to the thickness required1 which is generally half-an-inch2 these plates have holes punched all round them by machinery1 and are united by rivets placed in the holes red-hot and rivetted by heavy hammers4 ,the most magnificent specimen of iron shipbuilding ever attempted is the ,leviathan4 ,this ship is #fhj feet long1 and is not made of one thickness or case of iron plates1 but is upon a new principle called the 8cellular10 consisting of an outer and inner casing of iron plates held together by partitions of iron so as to separate them into square compartments or 8cells40 ,the objects gained by this arrangement are greater strength1 and greater safety1 for in case of injury to the outer portion1 the water would enter only between the two in that compartment where the injury happened to be1 and so fill only that small portion with water4 ,the whole ship is also divided into compartments by means of double screens of iron1 making it like a fire-proof box1 and even if a fire should occur in one of these1 the others would be preserved from its effects4 ,the masts and yards of this great ship are also of hollow wrought iron plates rivetted together1 and are both stronger and lighter than they would be of wood4 ,a machine is placed at the lower part of each mast which by compressing1 can crush it up1 and cause it to break off and fall over the side of the vessel in case such a thing should be required1 as in a very violent storm2 and the standing rigging1 which is of wire-rope1 can be let loose in a few minutes so as to completely free the ship of the mast4 ,this great ship is constructed to be propelled both by screw and paddles2 the screw engines are four in number1 and are each of #a1fjj horse power1 the paddle engines are also four1 of #ajjj horse power each1 being #aj1hjj altogether4 ,they will require about #ahj tons of coal a day to work them2 #ab1jjj tons of which are capable of being carried4 ,the ,leviathan will have six masts1 and be able to spread #f1ejj yards of sail1 will accommodate #djjj passengers1 and when ready to sail1 with all on board1 will weigh about #be1jjj tons4 ,,canals ,,and ,,locks4 ,illustration3 ,,double ,,lock4 ,canals are artificial water-courses1 either for the purpose of connecting rivers1 or for forming water communication for the conveyance of goods4 ,there are about #bbjj miles of canal-way in ,england1 which is still in complete requisition1 and but little affected by the enormous goods traffic of the railways4 ,canals afford a means of slow but cheap conveyance for heavy or bulky goods1 not requiring a rapid transit1 for the more rapid the pace the greater the resistance of the water4 ,the usual rate of transit is somewhere about two-and-a-half miles an hour1 at which pace a horse can draw about four times as much on water as he can on a railway1 and about thirty times as much as on a level turnpike road2 but if a greater speed were to be obtained1 it is found that the resistance of the water would impede it so much1 that at the rate of five miles an hour a horse could draw no more than he could on a railway1 and at ten miles only a quarter as much4 ,in constructing canals1 it is important to have a good supply of water1 and this is generally secured by turning all the springs and streams in its course into it1 or deriving its source at its highest level from a large river4 ,the same works have often to be constructed on the line of canals that are required on railways1 such as bridges1 cuttings1 embankments1 tunnels1 c41 and besides these1 contrivances peculiar to canals1 called 8locks10 which are now to be described4 ,locks are barriers or doors constructed so that these artificial rivers may be carried over rising ground and through valleys1 without the labour and expense of cutting through the hills and filling up the hollows as would be required without them4 ,railways can be constructed on ground which is not quite level without any embankment or cutting1 as it is not absolutely required that railways shall be perfectly level4 ,but water always will be level1 unless it is constantly flowing1 as is the case with streams1 and these only sink a few inches in a mile1 or else they become so rapid1 that if attempted to be imitated in canals1 they would be useless2 for it would require too much power to draw any vessel up the canal against such a stream1 and would moreover require more water to supply them than can commonly be obtained4 ,the means therefore adopted to overcome this difficulty are gates1 or in other words1 a pair of 8locks40 ,the canal is constructed in such a manner that it shall be perfectly level for a certain distance1 then sink down some ten or twelve feet at once1 and again flow on a level and sink down4 ,these sudden lowerings are effected as follows3 two pairs of thick solid doors of wood are fitted to shut in the water1 and another pair a short distance further on2 behind these the bed of the canal is lowered the required distance4 ,when a barge or other vessel has to pass down the canal the first pair of gates are opened1 and the barge floated in between them and the second pair1 the first pair are now closed1 and the water beyond the second pair being lower1 that between the gates in which the barge floats is let out by means of a valve worked by a rack and wheel2 when this valve is raised the water flows out and sinks down to the level of the water beyond1 carrying the barge with it2 in a few minutes it is so low that1 the second gates being opened1 the barge is drawn out and continues on its way4 ,but suppose the barge had to be brought up the canal1 then it is floated into the space between the gates 7as before71 and the one behind the barge closed1 the water beyond the gate in front being higher1 is let into the space where the barge is by a valve1 and this filling1 lifts up the barge to the level of that in front1 the front gates are then opened and the barge proceeds onwards4 ,these gates are never made to shut level1 but meet at an angle with the point towards the highest water1 which is done that they may resist the great pressure which the water exerts1 and for turning this to advantage1 for this very pressure shuts the gates and keeps them close together4 ,the canals which have much traffic on them have double locks1 as in the engraving1 that barges may go up and down at the same time without having to wait for each other4 ,the barges and boats are generally 8towed0 or drawn by a horse attached to a rope1 and walking on a 8towing path0 or road at the side of the canal4 ,,the ,,end4 ,transcriber's ,notes4 ,unit #a1 ,section3 ,,sulphur4 - #8sulphrous' replaced with #8sulphurous' 7fumes of sulphurous acid7 ,unit #a1 ,section3 ,,flax4 - #8,llnun' replaced with #8,linum' 7the flax plant ,linum ,usitatissimum7 ,unit #a1 ,section3 ,,silk4 - #8boddins' replaced with #8bobbins' 7on to bobbins or reels27 ,unit #b1 ,section3 ,,sugar4 - #8earthern' replaced with #8earthen' 7into conical earthen jars17 ,unit #b1 ,section3 ,,varnishes4 - #8varnised' replaced with #8varnished' 7before being varnished7 ,unit #b1 ,section3 ,,white ,,lead4 - #8earthern' replaced with #8earthen' 7a number of earthen pots7 ,unit #b1 ,section3 ,,white ,,lead4 - #8extremly' replaced with #8extremely' 7should be extremely careful7 ,unit #b1 ,section3 ,,white ,,lead4 - #8flim' replaced with #8film' 7a thin film of sulphate of lead7 ,unit #d1 ,section3 ,,gilding4 - #8is' replaced with #8in' 7sometimes done in this way7 ,unit #d1 ,section3 ,,electro-,,plating4 - #8in' replaced with #8is' 7or other object is plaster17 ,unit #e1 ,section3 ,,fire-,,arms ,,and ,,projectiles4 - #8,,minie' replaced with #8,,mini' 7,,machine ,,for ,,making ,,mini ,,rifle ,,bullets47 ,unit #e1 ,section3 ,,percussion ,,caps4 - #8,woolwhich' replaced with #8,woolwich' 7,at the ,arsenal at ,woolwich7 ,unit #e1 ,section3 ,,ploughs4 - ,the #8skim-coulter' ,f is shown in the plough illustration as ,e4 ,unit #f1 ,section3 ,,railways4 - #8waggon' replaced with #8wagon' 7the wagon should be so great47 ,unit #f1 ,section3 ,,railways4 - duplicate word #8part' removed 7and on this part it supports7 ,unit #f1 ,section3 ,,railways4 - #8effect' replaced with #8effects' 7this he effects by what7 ,unit #f1 ,section3 ,,electric ,,telegraphs4 - #8commniucation' replaced with #8communication' 7from all communication with the earth7 ,unit #f1 ,section3 ,,artesian ,,wells4 - ,,fig4 #a4 and ,,fig4 #b4 were reversed4 ,unit #f1 ,section3 ,,artesian ,,wells4 - #8,artisian' replaced with #8,artesian' 7,artesian wells are sunk7 ,unit #f1 ,section3 ,,mines4 - #8ncessary' replaced with #8necessary' 7,it is therefore necessary7 ,unit #f1 ,section3 ,,ships4 - #8,f' omitted from ,,fig4 #a