Part 5 (1/2)

We have mentioned that accidents have frequently occurred fro of ”coal-pipes,” or, as they are also called, ”bell-moulds” We must explain what is meant by this term They are simply what appear to be solid trunks of trees o into a tropical forest we find that the woody fibre of dead trees almost invariably decays faster than the bark The result is that whatbut an empty cylinder of bark This appears to have been the case with many of the trees in coal-mines, where they are seen to pierce the strata, and around which thethe coal As the coalyfor a process of decomposition, while the bark assumed the form of coal The hollow interior then became filled with the shale or sandstone which forms the roof of the coal, and its sole support when the coal is removed from around it, is the thin rind of carbonised bark When this falls to pieces, or loses its cohesion, the sandstone trunk falls of its oeight, often causing the death of the man that works beneath it Sir Charles Lyell mentions that in a colliery near Newcastle, no less than thirty _sigillaria_ trees were standing in their natural position in an area of fifty yards square, the interior in each case being sandstone, which was surrounded by a bark of friable coal

[Illustration: Fig 33--Part of a trunk of _Sigillaria_, showing the thin outer carbonised bark, with leaf-scars, and the seal-like ireat danger to which we have here to make reference, is the explosive action of a quantity of coal-dust in a dry condition It is only now conised that this is really a e quantities of coal are formed almost exclusively of _lepidodendron_ spores, and such coal is productive of a great quantity of dust Explosions which are always enerally considered, in the official statistics, to have been caused by fire-da mines in Great Britain is scarcely up to date in this respect There is a regulation which provides for the watering of all dry and dusty places within twenty yards from the spot where a shot is fired, but the enforceulation in each and every pit necessarily devolves on the ers, many of whom in the absence of an inspector leave the requirement a dead letter Every improvement which results in the better ventilation of a coal-erous condition The air, as it descends the shaft and pers, becomes more and more heated, and licks up every particle of reatly freeing a s about another disease, viz, the drying-up of all erously inflaunpowder, to be started, it htest breath of an explosion There is apparently little doubt that the presence of coal-dust in a dry state in a mine appreciably increases the liability of explosion in that mine

So far as Great Britain is concerned, a Royal Commission was appointed by Lord Rosebery's Govern to coal-dust Generally speaking, the conclusion arrived at was that fine coal-dust was inflammable under certain conditions There was considerable difference of opinion as to what these conditions were Some were of opinion that coal-dust and air alone were of an explosive nature, whilst others thought that alone they were not, but that the addition of a small quantity of fire-damp rendered the mixture explosive An important conclusion was come to, that, with the combustion of coal-dust alone, there was little or no concussion, and that the flame was not of an explosive character

Coal-dust was, however, aderous, especially if in a dry condition The effects of an explosion of gas ht be considerably extended by its presence, and there seems every reason to believe that, with a suitable adas, it forislation in the direction of the report of the Coently needed

We have seen elsewhere what it is in the dust which erous, how that, for the most part, it consists of the dust-like spores of the _lepidodendron_ tree, fine and i ferns, and the fact that this consists of a large proportion of resinbut an incessant watering of the workings in such cases will render the dust innocuous The dust is extremely fine, and is easily carried into every nook and crevice, and when, as at Bridgend in 1892, it explodes, it is driven up and out of the shaft, enveloping everything temporarily in dust and darkness

In some of the pits in South Wales a system of fine sprays of water is in use, by which the water is ejected from pin-holes pricked in a series of pipes which are carried through the workings A fine mist is thus caused where necessary, which is carried forward by the force of the ventilating current

A thorough systehout the world is undoubtedly urgently called for, in order to ensure the proper carrying out of the various regulations framed for their safety It is extremely unfortunate that so many of the accidents which happen are preventable, if only e and of scientific attainments filled the responsible positions of the overlookers

CHAPTER V

EARLY HISTORY--ITS USE AND ITS ABUSE

The extensive use of coal throughout the civilised world for purposes of heating and illu on of arded as a well-e in which we live

Coal enerations Peoplein close proximity to its outcrops at the sides of theacquainted with its practical value, and it seee that so little use was o, and that its use did not spread earlier and hout civilised countries

A mineral fuel is mentioned by Theophrastus about 300 BC, fro from some of the more shallow depths The Britons before the tiht knowledge of its industrial value Prehistoric excavations have been found in Monmouthshi+re, and at Stanley, in Derbyshi+re, and the flint axes there actually found imbedded in the layer of coal are reasonably held to indicate its excavation by neolithic or palaeolithic (stone-age) workmen

The fact that coal cinders have been found on old Rooes to prove that its use, at least for heating purposes, was known in England prior to the Saxon invasion, whilst solas, in Lancashi+re, are supposed also to be Roman

The Chinese were early acquainted with the existence of coal, and knew of its industrial value to the extent of using it for the baking of porcelain

The fact of its extensive existence in Great Britain, and the valuable uses to which it ht be put, did not, however,to the decrease of the forest-area, and consequently of the supply of wood-charcoal therefro an excellent substitute for charcoal

The coal-miner was, however, still a creation of the future, and even as peat is collected in Ireland at the present day for fuel, without the laborious process ofdistricts found their needs satisfied by the quantity of coal, small as it hich appeared ready to hand on the sides of the carboniferoustime afterwards, the principal source of fuel consisted of vast forests, amidst which the charcoal-burners, or ”colliers” as they were even then called, lived out their lonely existence in preparing charcoal and heood, for the fires of the baronial halls and stately castles then swarhout the land As the forests became used up, recourse was hadwith and recognising the iranted to the free for coals in the Castle fields About the saranted to the monks of Newbattle

Specimens of Newcastle coal were sent to London, but the city was loth to adopt its use, objecting to the innovation as one prejudicial to the health of its citizens By the end of the 16th century, two shi+ps only were found sufficient to satisfy the deressto the difficulties which were placed in the way of its universal use Great opposition was experienced by those who i amount which was used by brewers and others about the year 1300, caused serious complaints to be made, the effect of which was to induce Parlia its use, and e the justices to inflict a fine on those who persisted in burning it The nuisance which coal has since proved itself, in the pollution of the at of wide tracts of country of all vegetation, was even thus early recognised, and had the efforts which were then made to stareat cities ht never have beco which at tihtness of day into a darkness little reht At the same tied that England owes her prosperity, and her pre-ereat part, to her happy possession of wide and valuable coal-fields, and many authorities have not hesitated to say, that, in their opinion, the length of tiland will continue to hold her prominent position as an industrial nation is li which her coal will last

The atte of coal was not, however, very successful, for in the reign of Edward III a license was again granted to the free for coals Newcastle was thus the first town to become famous as the home of the coal-miner, and the faly ever since

Other attempts at prohibition of the article wereone which was n

It was supposed that the health of the country squires, who came to town to attend the session of Parlia their sojourn in London, and, to remedy this serious state of affairs, the use of stone-coal during the ti was once inning to be recognised as a most valuable and useful article of fuel, and had taken a position in the industrial life of the country from which it was difficult to rerowing use of coal, Parliament would have been better e the e burners to consu at total prohibition, have encouraged an intelligent and more economical use of it

In spite of all prohibition its use rapidly spread, and it was soon applied to the sely produced in the south of England fro the existence of the great forest which at one tihout Surrey and Sussex The discovery of coal, however, and the opening up of ave an i of iron in those counties, and as the forests of the Weald becaradually declined Furnace after furnace becauished, until in 1809 that at Ashburnhaered on for some years, was compelled to bow to the inevitable fate which had overtaken the rest of the iron blast-furnaces

In referring to this subject, Sir James Picton says:--”Ironstone of excellent quality is found in various parts of the county, and was very early made use of Even before the advent of the Romans, the Forest of Dean in the west, and the Forest of Anderida, in Sussex, in the east, were the two principal sources froh the es the manufacture was continued After the discovery of the art of s iron in the sixteenth century, the reat impulse from the abundance of wood for fuel, and from that time down to the middle of the last century it continued to flourish One of the largest furnaces was at Lamberhurst, on the borders of Kent, where the noble balustrade surrounding St Paul's Cathedral was cast at a cost of about 11,000 It is stated by the historian Holinshed that the first cast-iron ordnance was manufactured at Buxted Two specialities in the iron trade belonged to Sussex, the rave-stones At the time ood constituted the fuel the backs of fire-places were frequently ornans Specimens, both of the chimney-backs and of the monuments, are occasionally met with