tions determine at what distance beyond the coast the greatest depression of the coal-beds will be found, we are completely at fault as to the quantity of coal lying underneath the sea. * We have not yet reached the threshold of such a conjecture. We have not yet explored one square mile of this vast unknown space, or determined one of the many elements required in such an intricate and uncertain investigation." To a certain extent, these remarks will apply with all their force to other localities. The difficulties determining the existence of coal, and its quantity, under several unexplored regions are exceedingly great, and until opened out, it could only be approximately estimated. Still we cannot but think the concluding remark of the Reporters, that "such an investigation can be of no practical utility, and that the attempt for a vast period of time is, at the least, premature," is one induced, rather by the influences of commerce, looking only to the present, than by the broader spirit of philanthropy which embraces the future. It may not be out of place here to caution the less scientific of our readers from receiving, as in any way probable, that speculation which is echoed from book to book promising man that science will find, when, coal is exhausted, some other source of heat and light, which shall be equally economical and as easy of application. If those speculative minds, who suppose the time will come when the constituents of water will be burnt, or electricity be made an unfailing producer of heat, would but carefully entertain the fact, that every form of physical force is the result of the destruction (change of form) of matter somewhere, they would be more cautious in promulgating their unsupported hypotheses. То burn zinc or iron in a voltaic battery to produce heat or light, must always be infinitely more costly than burning coal in a furnace. The lamentable catastrophes which from time to time occur in our collieries, awaken public attention, and excite the utmost sympathy for the sorrowing survivors. That there is a deep-felt desire to assuage the flood of misery which falls, tempest-like, upon a colliery village; and so far to improve the conditions under which the coalminer labours, as to render the risks less imminent to him, is proved by the manner in which money was poured into the Hartley Fund. After some delay, the large sum whch remained unexpended, after every necessary want had been satisfied amongst the widows and orphans of those poor men who perished so miserably in that Colliery, has been distributed to other districts for the purpose of forming the nucleus of local funds to meet such exigencies as may unhappily arise. The public expression of feeling is loud, it will be heard and attended to; but, independently of the impulse which is due to this voice, it must not be forgotten that numerous minds are, and have been silently and earnestly at work, aiming to improve all the conditions of our collieries, and so to render accidents less common. We have lately, at the Morfa Colliery, in South Wales, had an explosion of fire-damp, by which 39 men were destroyed. This serious accident occurred in a colliery remarkable for its very excellent arrangements. The works were carried on under the most skilled colliery engineers; the ventilation was excellent; locked safety-lamps were always used; and the strictness with which a well-devised code of rules was enforced appeared to secure this colliery from accident by explosion. Yet, when least expected, the fire-damp accumulates, and mysteriously it is fired, sweeping away in a moment 39 men, and strewing wreck around in its deadly progress. This sad accident should teach us that we must not suppose we can, by any skill or care, secure absolute immunity from casualties of this class. In all probability the Morfa explosion arose from a sudden outburst of carburetted hydrogen gas, attended with a fall of the roof, by which the wire gauze of a safety-lamp became broken. It is important that a record should be prominently made of the fact, that the proprietors of this colliery, the Messrs. Vivian, refused the aid which the public readily offered, and that they take upon themselves the burthen of supporting the widows and orphans of those who perished in their employment. Knowing the imperfections of human nature, and the power exerted by selfishness over the better feelings of the heart, we are persuaded that both master and man would be permanently benefited by a legislative enactment, rendering it imperative that the Colliery proprietor should be responsible for the maintenance of the widow and the child of the collier, who has perished by accident in his pit. With such a provision, a more searching system of inspection would be introduced; the workings would be kept in better order; rules would be more rigidly enforced; and, as a consequence, the coal would be obtained in better condition, and at less cost, than at present. Beyond this, the Colliery proprietors would speedily protect themselves by forming funds to meet the exigencies as they arose. A course of this kind is the only one left for trial: there is surely philanthropy enough in this Christian land to force on the experiment. In nearly every division of human labour, some mechanical power has been introduced for the purpose of relieving the labourer from the constant strain made upon his muscular system. The coal-hewer has not, however, been in any way assisted. With the primitive pick and the ancient wedge, he has been compelled, often under the most trying conditions, to "get" the coal. This state of things may be accounted for by the circumstance that Mining work is performed in. the deep and dark bowels of the earth, where there is little to attract, and much to repel, such minds as usually give birth to appliances of physical force. The subject has not been, however, entirely neglected. So long since as 1789, a patent appears to have been granted for improved machinery to be used in getting coal, and since that time many plans have been proposed, and some of them patented, though none have been successfully applied. The first machine which has been found capable of taking its place in the regular business of coalcutting is one belonging to the West Ardsley Coal Company, Messrs. Firth, Donisthorpe, and Bower. This machine has been in regular work during the last twelve months, and it appears to be admirably adapted to the purpose for which it is contrived. The Machine-shown on the adjoining plate-is carried on a castmetal frame of great firmness, the size and weight varying to suit the condition and thickness of the bed of coal to be operated upon. An Engine is mounted within this framework: it is actuated by compressed air, and so arranged as to give the blow of the pick or cutter, either by the pull or the push of the piston. Almost any form of engine is applicable, but that which is employed with advantage in practice at Ardsley Colliery, is the oscillating cylinder principle, whereby is obtained compactness of form and diminished friction in the working parts. The whole is carried upon wheels with flanges, sometimes single and sometimes double, as may be required by the nature of the work. It is propelled backward and forward by a wheel and screw, or a ratchet and pawl, which is fized on one side. On the other side is the valve-lever to regulate the admission and the emission of the air, and the stroke of the piston when the Machine is at work; the man in charge of it moves the ratchet-lever, which is connected with the gearing of the under-carriage, and thus pushes up the carriage on the tram, a distance equal to the cut of the previous blow; and so moves on to the end of the "bank," or working face of the coal. In seams of three feet, or upwards in thickness, the man may sit on a movable seat fixed at the end of the Machine, but in thin seams this cannot be done, and he has to kneel on a truck running on low pulleys or rollers which travel in the rear of the cuttingmachine. The cut, or groove of the coal, made by hand-labour, is a triangular opening varying in size according to the hardness and nature of the coal, but averaging from 9 to 12 inches. In firm coal the machine makes a cut which is not usually more than 24 inches' opening, and the under-cut is taken 3 feet into the coal. The Ardsley Coal Company state that the coal is obtained in a better condition by machine, than by hand cutting, so much so that about 1s. a ton more can be obtained for the coal, on the yield of the seam. A matter of more importance than this is urged by the proprietors, viz. the diminished risk to the persons and lives of the employed. Numerous lives are lost by falls of coal. It will be well understood, that, if the miner has made an opening in the lower part of the coal, which shall be 12 inches wide on the face, and the superincumbent mass of coal should by its weight fall, much care will be required on the part of the workman to keep himself harmless. Often, when working in a constrained position, the coalhewer, unable to relieve himself from the falling masses, is crushed to death. By the machine work there is much less liability to this kind of accident. The groove being narrow can be spragged with ease and system, and a slip in the coal only closes up the groove. In ordinary cases the coal is not pushed out; but, if it does come forward, there is little danger to the workman, because he can readily get out of the way, and if it catches the machine but little injury is done. There are some technical advantages, beyond those named, which need not be noticed in this Journal. The length of the coal-cutting machine which we have described, has been thought by some to be a disadvantage. Difficulties are said to have arisen when it was required to be taken round the short elbows, and the abrupt curves, which often occur in a colliery. To obviate this |