them as their responsible ministers; but it is not difficult to plunge a youthful constitution into troubles which would be too much for the strength even of the oldest and most consolidated dominion. No one can contemplate, without a shudder, the idea of civil war between the two principal races which form the European population, and which have, by a combination of diverse great qualities, raised the Colony to its present condition of strength and prosperity. It would be impossible to forecast the future of such communities, but if the English Government were to repudiate its responsibilities in South Africa, I see no better prospect for some generations than the formation of a knot of small antagonistic republics, more or less civilised, but for the most part closely approaching the type of the Republics which have succeeded Spanish dominion in South America.

The first thought of the English Government should be to enforce submission to the law in the province which has rebelled against it, to re-establish a government able to protect person and property, and to defend the order which is indispensable to the existence of a civilised State; and by so doing to redeem the first and most important of the promises made to the people of the Transvaal on its annexation.

This having been done, no time should be lost in amending the constitution of the Transvaal, and making it more conformable to the wants and wishes of the population. This would not be difficult to arrange. I have already referred to the scheme drawn up for the consideration of Her Majesty's Government, and embracing the suggestions of some of the leading statesmen and jurists of the Cape Colony, and also of the able president of the Orange Free State. I should look with great confidence to the successful working of any Transvaal constitution which had the approval of Mr. Sprigg and his colleagues, and of Mr. Brand.

On another occasion I hope to indicate in what directions the most important modifications should, in my own opinion, be made, to secure unity of policy in all such important matters as the native question throughout all the English colonies in South Africa, and how, by co-operating with the Portuguese Government, we may set definite bounds to any extension of English responsibilities to the north of the Orange River and Limpopo basins; and so fix geographical limits within which the Anglo-Dutch subjects of the British Crown, and the people of the Orange Free State, shall have scope to grow as self-defending and self-governing dominions.

All I would now say is, let us beware of sending out cut and dried constitutions from England to a people like that of the Transvaal.

Of no people is it more true that their institutions must grow with them, or be adapted to all their peculiarities. The only way in which a good working constitution can be framed for a country in the position of the Transvaal is to give large powers to an experienced administrator on the spot, to draw up such a constitution as will be approved by the best men among the Boers themselves, as well as by the intelligent and experienced statesmen who rule the destinies of similar and kindred communities in the Orange Free State and the Cape Colony.

H. B. E. FRERE.

EXPLOSIONS IN COLLIERIES AND
THEIR CURE.

6

I HAVE read Mr. Plimsoll's article in the December number of the Nineteenth Century, on Explosions in Collieries and their Cure;' and, agreeing with him that their cure is within the possibilities of science, beg to add my appeal on behalf of the miner to scientific

For mining is now no longer a matter of rule of thumb, and we cannot hope for any real improvement except from persons who are thoroughly well acquainted with those natural laws upon which all science is based. But before they are in a position to grapple with the question, it seems to me essential that the way should be cleared for them by some one practically acquainted with mining, lest their energies be wasted over impracticable schemes, or in the solution of problems not directly bearing upon the point at issue. I propose, therefore, first, to point out one or two errors into which, it appears to me, Mr. Plimsoll, in common with more than one person of the highest scientific attainments, but, as I may conclude, practically unacquainted with mining, has fallen; and, secondly, to lay before your readers the real problem which I believe must be solved before we can hope to place any definite limit to these disastrous

accidents.

Perhaps I should premise, in order to elucidate further a subject so technical as mining, that coal is found in beds varying in thickness from a few inches up to several feet, and extending with great regularity over large areas. These beds are seldom found lying either quite horizontally, or quite vertically, but are found inclined at all angles between these two extremes. There is also a great variety in the quality of the seams of coal, in the quantities of gas that exude from them, and in the character of the rocks between which they lie. We should, therefore, be naturally led to anticipate, and rightly so, that there are many systems of working coal so as to suit these varying conditions of its occurrence.

It would be impossible, within the limits of this paper, to describe even the more important of these methods, but I will try, in a few words, to make one of them-viz. the Board and Pillar' system of the North of England-sufficiently intelligible to your readers for my

6

purpose. I choose this method of working the coal for explanation in preference to others, because in connection with it goaf-drainage was, I believe, first mooted. This system of coal working will be readily understood from a consideration of it, as illustrated by the name échiquier' which it bears in France and Belgium. The black and white squares represent the pillars of coal left during the first working to support the roof of the mine. The lines separating these squares are the drifts or excavations made in the coal during the first working, or in working the whole,' as it is called. Afterwards the black and white squares, i.e. the pillars which have been left to support the strata above, are removed; and this, the second working, is called 'working the broken,' or 'working out the pillars.” The empty area left by the extraction of the coal, which, however, is soon filled up by falls of stone from the strata overlying the bed, is called the 'goaf.' This term 'goaf,' plural 'goaves,' is applied to the area from which the coal has been extracted, whatever be the system of working employed. I shall have more to say about the character of a goaf presently.

A seam, when first cut, gives off inflammable gases in larger or smaller quantities, according to the character of the coal, which gases, as Mr. Plimsoll has pointed out, being lighter than air, tend to collect in the higher parts of the workings. When mixed with air, in the proportion of one volume of gas to from five to fourteen volumes of air, they become explosive; and one of the principal objects of ventilation is to dilute these gases with sufficient air, so as to render them harmless, and then to carry them off out of the mine. By gas I shall here mean these inflammable gases, and by fire-damp an explosive mixture of these gases and air.

I shall pass quickly over the first four of Mr. Plimsoll's suggestions. Three of them-viz. mordants, collodion balloons, and absorption-would no doubt render valuable aid to the miner if practicable; but whether they are so or not I must leave to chemists to decide. One, the absorption of the gas, has already been attempted, but hitherto without success. The fourth suggestion, the explosion of the gas in regulated quantities after careful examination of its first beginning to accumulate, was the system in vogue before the invention of the safety-lamp. Simonin mentions it in his book, La Vie souterraine, page 179, where also may be seen an engraving of the miner in the dress specially adapted to his dangerous work. I cannot do better than quote his description :

En France, à Rive-de-Gier, on se rappelle encore le temps où un homme, courageux entre tous, venait tous les soirs enflammer le gaz dans la mine, en provoquer l'explosion, pour que les chantiers fussent de nouveau accessibles le lendemain.

I see, in connection with the Penygraig accident, which happened so recently as December 10, that the Rev. T. Jones, of Rhymney, is confident that he has now discovered the solution of his problem.

Roulé dans une couverture de laine ou de cuir, la figure protégée par un masque, la tête couverte d'un capuchon analogue à la cagoule des moines, il rampait sur le sol pour se tenir autant que possible dans la couche d'air respirable, car le grisou, plus léger que l'air, monte toujours au sommet des galeries. Il tenait d'une main un long baton, au bout duquel était une chandelle allumée; et il allait seul, perdu dans ce dédale empoisonné, provoquant les explosions par l'approche de sa lampe et décomposant ainsi le gaz pernicieux. On l'appelait le pénitent, à cause de la ressemblance de son costume avec celui des ordres religieux; et ce mot semblait en même temps dicté par une dérision amère, car souvent le pénitent, victime sacrifiée d'avance, ne revenait pas, emporté par l'explosion. Sur d'autres mines on nommait ce brave houilleur le canonnier. Quand le grisou le tuait sur place, on disait que le canonnier était mort à son poste, au champ d'honneur, et c'était là toute son oraison funèbre. Le même ouvrier portait dans les mines anglaises le nom expressif de fireman, ou l'homme du feu.

I need hardly add, that though this system, under very careful management, might do some good service, it has long since been abandoned.

The method of ventilation proposed by Mr. Plimsoll is good; for not only is the gas lighter than air, as he has pointed out, but the air of the mine, being heated by contact with the warm surface of the stony strata, is lighter than the cool air coming down from the surface, and for the same reason it becomes lighter and lighter the further it travels through the passages of the mine. Its natural tendency is, therefore, to rise, like the gas, as it proceeds on its course towards the upcast shaft; and accordingly the current of air, as well as the gas, is most easily kept in circulation when this natural tendency is not obstructed. The downcast, or shaft for entry of air, should therefore be placed near the lowest point of the area of the coal working; the upcast, or shaft for exit of air, near the highest (the area being in almost all cases on an incline). This, a fact well known to mining engineers, is called ascensional ventilation, and is always carried out in the working where practicable; but sometimes it is impossible to carry it out effectually, for many conflicting interests may interfere with the choice of a situation for the shafts of a mine.

I now come to Mr. Plimsoll's principal suggestion-viz. that the gas should be drained off by means of a pipe placed in a hole or 'sump' made for it in the roof of the upper exhausted spaces in a pit, i.e. in the highest point of the goaf, and carried from this sump to the upcast shaft. This idea was brought forward, whether for the first time or not I cannot say, by Messrs. Faraday and Lyell at the Haswell Colliery explosion in 1844. A description of their apparatus was published by them in the Philosophical Magazine (third series, vol. xxvi. p. 16). A committee of mining engineers was appointed by the coal-trade of the north of England to examine and report upon this scheme. After a most careful consideration of the matter, they pronounced it not only infeasible, but of very doubtful benefit,