Part 4 (2/2)

It is therefore necessary to introduce soular current shall pass down one shaft, through the s, and out at the other shaft This is accomplished in various ways It took hly to understand how properly to secure ventilation, and in bygone days the systehly bad that a tre to the poisonous effects of breathing the saed, as it ith iven off by the coal itself Now, thosetheour houses in winter, have the best contrivances which can be devised to furnish thest the various mechanical appliances which have been used to ensure ventilation may be mentioned pumps, fans, and pneuh slight, movement of the air in the two columns which constitute the upcast and the downcast shafts, but in order that a current may flohich shall be equal to the necessities of the miners, some means are necessary, by which this condition of almost equilibrium shall be considerably disturbed, and a current created which shall sweep all foul gases before it One plan was to force fresh air into the downcast, which should in a sense push the foetid air away by the upcast Another was to exhaust the upcast, and so draw the gases in the train of the exhausted air In other cases the plan was adopted of providing a continual falling of water down the downcast shaft

These various plans have aliven way to that which is thean i in a specially-constructed chamber at the bottom of the upcast By this means the column of air above it becomes rarefied under the heat, and ascends, whilst the cooler air from the downcast rushes in and spreads itself in all directions whence the bad air has already been drawn On the other hand, to so great a state of perfection have ventilating fans been brought, that one was recently erected which would be capable of changing the air of West procured a current of sufficient power, it will be at once understood that, if left to its oill, it would take the nearest path which ht lie between its entrance and its exit, and, in this way, ventilating the principal street only, would leave all the many off-shoots from it undisturbed It is consequentlydoors, in such a way that the current is bound in turn to traverse every portion of the e nu the doors to all co the doors immediately after they have passed, in order that the currentwhich it is not intended that it should pass

The greatest dangers which await the miners are those which result, in the forases in the es in as into the air When a bank of coal is brought down by an artificial explosion, by dynae quantities of gas are sohly detrimental to the health of the miners, if not carried away by proper ventilation, but it constitutes a constant danger which ht into contact with it Fire-da fro sound

If the voluas forms what is called a _blower_, and this often happens in the neighbourhood of a fault When coal is brought down in any large volume, the blohich commence may be exhausted in a few moments Others, however, have been known to last for years, this being the case at Wallsend, where the blower gave off 120 feet of gas per as is usually conveyed in pipes to a place where it can be burned in safety

In the early days of coal-as soon received the serious attention of the scientific e In the _Philosophical Transactions of the Royal Society_ we find a record of a gas explosion in 1677 The a part of such records was that the explosions were ascribed by the encies Little attention seehly been established, that the explosions were caused by accuas, mixed in certain proportions with air As a consequence, tallow candles with an exposed flame were freely used, especially in Britain These were placed in niches in the workings, where they would give to the pitht Previous to the introduction of the safety-las were tested before theto the specific gravity of fire-daes, so that, to test the condition of the air, it was necessary to steadily raise the candle to the roof at certain places in the passages, and watch carefully the action of the flame The presence of fire-da a blue colour, and by its elongation; the presence of other gases could be detected by an experienced man by certain peculiarities in the tint of the fla with the open flame has almost entirely ceased since the introduction of the perfected Davy laave place in e collieries to the introduction of small oil-lamps In the less fiery mines on the Continent, oil-lamps of the well-known Etruscan pattern are still in use, whilst small metal lamps, which can conveniently be attached to the cap of the worker, occasionally find favour in the shallower Scotchthe coal froress has to be made on the hands and feet At the close of the last century, as workings began to be carried deeper, and coal was obtained from places more and more infested with fire-damp, it soon came to be realised that the old methods of illumination would have to be replaced by others of a safer nature

It is noteworthy that nite fire-da necessary for this purpose

Bearing this in , the discoverer of the fact, invented what is known as the ”steel- purposes In this a toothed wheel was made to play upon a piece of steel, the sparks thus caused being sufficient to give a moderate amount of illumination It was found, however, that this method was not always trustworthy, and lamps were introduced by Humboldt in 1796, and by Clanny in 1806 In these lamps the air which fed the fla to bubble through a liquid Many miners were not, however, provided with these lahts went on as merrily as ever

In order to avoid explosions in as, ”fiery” pits as they are called, Sir Humphrey Davy in 1815 invented his safety lamp, the principle of which can be stated in a feords

If a piece of fine wire gauze be held over a gas-jet before it is lit, and the gas be then turned on, it can be lit above the gauze, but the flaas; at least, not until the gauze has becoauze so rapidly conducts away the heat, that the teauze is unable to arrive at the point of ignition In the safety-lamp the little oil-laauze, which prevents the flaas thatabout outside, but at the sah readily Sir Huainst exposing it to a rapid current of air, which would operate in such a way as to force the flaauze to become red-hot In order to minimise, as far as possible, the necessity of such caution the lamp has been considerablycurrents not now allowing of the use of the si the progress of Sir Humphrey Davy's experiments, he found that when fire-damp was diluted with 85 per cent of air, and any less proportion, it sinited without explosion With between 85 per cent and 89 per cent of air, fire-damp assumed its most explosive form, but afterwards decreased in explosiveness, until with 94-1/4 per cent of air it again sinited without explosion With between 11 and 12 per cent of fire-daerous Pure fire-daerous, so that when a sauze which surrounds the Davy lamp, it simply burns with its characteristic blue flaives the

[Illustration: FIG 32--Gas Jet and Davy Lamp]

With the complicated improvements which have since been made in the Davy lauaranteed, but still from time to time explosions are reported Of the cause of ht is thrown upon their origin by a paragraph appearing in a daily paper Twoin the possession of keys used exclusively for unlocking their miners' safety-lamps There is no defence These men know that they carry their lives in their hands, yet will risk their own and those of hundreds of others, in order that they ht their pipes by means of their safety-lareat dislodgeas is set free, which es for some distance around The introduction or exposure of a naked light for even so much as a second is sufficient to cause explosion of theare charred up, and the volu up by the nearest shaft and overthrowing the engine-house and other structures at the e to those at the surface, of the dreadful catastrophe that has happened below

Perhaps all that remains of some of the workers consists of charred and scorched bodies, scarcely recognisable as hued hair, to tell the terrible tale to those ere s when, after having escaped the worst effects of the explosion, they encountered the asphyxiating rush of the after-damp or choke-damp, which had been caused by the combustion of the fire-damp ”Choke-damp” in very truth it is, for it is principally coas (carbon dioxide), which is well known as a non-supporter of combustion and as an asphyxiator of ani that on occasions the workings and walls themselves of a coal-mine catch fire and burn incessantly Yet such is the case Years ago this happened in the case of an old colliery near Dudley, at the surface of which, by means of the heat and steam thus afforded, early potatoes for the Londonto see the s from cracks and crevices in the rocks in the vicinity of the town

Froer which awaits reat coal strike of 1893, certain mines became unworkable in consequence of the quantity of water which flooded thethe natural fractures in the earth's crust, is always ready to find a storage reservoir in the workings of a coal-mine This is a difficulty which is always experienced in the sinking of shafts, and the shutting off of water engages the best efforts of ers which exist in the coal-mine, we must not o caused by the falling-in of roofs or of walls, fro of insecure timber, or of what are known as ”coal-pipes” or ”bell-ain, every e by which he descends to his labour, and shaft accidents are not infrequent

The following table shows the number of deaths from colliery accidents for a period of ten years, compiled by a Government inspector, and fro roofs number considerably more than one-third of the whole

------------------------------------------------------------------- | Causes of Death | No of | Proportion | | | Deaths | per cent | ------------------------------------------------------------------- | Deaths resulting from fire-damp | | | | explosions | 2019 | 2036 | | | | | | Deaths resulting fro | | | | roofs and coals | 3953 | 3987 | | | | | | Deaths resulting from shaft | | | | accidents | 1710 | 1724 | | | | | | Deaths resulting froround | 2234 | 2253 | | |------------|------------| | | 9916 | 10000 | ------------------------------------------------------------------|

Every reader of the daily papers is faiven of coal-mine explosions

This kind of accident is one, which is, above all, associated in the public ers of the coal-pit Yet the accidents arising froranted there be proper inspection, and the use of naked lights be absolutely abolished, this low percentage ht still be considerably reduced

A terrific explosion occurred at Whitwick Colliery, Leicestershi+re, in 1893, when two lads were killed, whilst a third was rescued after a very narrow escape The lads, it is stated, _orking with naked lights_, when a sudden fall of coal released a quantity of gas, and an immediate explosion was the natural result Accidents had been so rare at this pit that it was regarded as particularly safe, and it was alleged that the use of naked lights was not uncoe number of accidents which are undoubtedly preventable

An interesting commentary on the careless manner in which miners risk their lives was shown in the discoveries made after an explosion at a colliery near Wrexham in 1889 Near the scene of the explosion an unsecured safety laeneral opinion at the time was that the disaster was caused by the inexcusable carelessness of one of the twenty victi of the bodies recovered was searched, the contents, taken, it should be noted, with the pitmen into the mines, consisted of pipes, tobacco, e reflection on the manner in which thisupon their work, that the under-looker, but half an hour previously, had reported the pit to be free froas

Another instance of the same foolhardiness on the part of the ard to an explosion which occurred at Denny, in Stirlingshi+re, on April 26th, 1895 By this accident thirteen ht of the nu articles were found; upon Patrick Carr, tinla la la lamps; John Herron, clay pipe and piece of tobacco; Henry M'Govern, tin matchbox half full of matches; Robert Mitchell, clay pipe and piece of tobacco; John Nicol, wooden pipe, piece of tobacco, one match, and box half full of matches

The report stated that the inition of fire-da such as to exclude the possibility of spontaneous combustion Henry M'Govern had previously been convicted of having a pipe in the ard to the question of sufficient ventilation it continued:--”And we are therefore led, on a consideration of the whole evidence, to the conclusion that the accident cannot be attributed to the absence of ventilation, which the ulation Act and the special rules to provide” The report concluded as follows:-- ”On the whole matter we have to report that, in our opinion, the explosion at Quarter Pit on April 26th, 1895, resulting in the loss of thirteen lives, was caused by the ignition of an accu in contact with a naked light, 'other than an open safety-lamp,' which had been unlawfully kindled by one of the miners ere killed In our opinion, the intensity of the explosion was aggravated, and its area extended, by the ignition of coal-dust”