A great improvement has been effected of late years in the facility of transporting minerals underground, by the introduction of small tramroads, and the saving of expense thus effected sometimes amounts to one-half the former cost. Many of our larger mines are provided with miles of this subterranean railroad, and the advantage is greater, because for the most part there is a slight descent from the workings to the bottom of the shaft, to allow of a more complete system of drainage than could otherwise be attained. But frequently where the galleries are low, narrow, and crooked, the carriage is still effected by means of sledges, barrows, or little waggons, which are with difficulty dragged or pushed along, over planks or uneven and muddy roads; and sometimes even the interior transport of the ore is executed on the backs of men—a most disadvantageous practice, which is gradually wearing out. [Illustration: CONVEYANCE OF MINERALS UNDERGROUND.] In great mines, such as the coal and salt mines of Great Britain, the salt mines of Wielitzka, the copper mines of Fahlun, the lead mines of Alston Moor, horses have long been introduced into the workings, to drag heavier waggons, or a train of waggons attached to one another. In some cases these animals are brought to the surface at stated intervals, but generally when once let down the pit they for ever bid adieu to the light of day. Strange to say, this _unnatural_ mode of existence, which would soon undermine the vigour and spirits of man, agrees admirably well with their health, of which the greatest care is taken, as their useful services are duly appreciated by their owners. They are abundantly fed with hay and oats of the best quality; their stalls are large and well ventilated; and as they labour in a mild and equable temperature, they remain free from many complaints to which horses are liable. Their good condition and sleek, shining coats prove that they have no sentimental longing for green fields or the bright sunshine. In a few of the largest collieries it has been found advantageous to establish underground stationary engines, which bring the trains of waggons, by means of an endless rope, along the galleries to the bottom of the shaft. In other mines, such as those of Worsley in Lancashire, subterranean canals are cut, upon which the mineral is transported in boats. In the European mines, the ores are usually lifted from the bottom of the shaft to the surface by steam-power, or horse-gins; but in Spanish America, men, and even women, are employed for this purpose. The steep ladders which they ascend with heavy weights upon their backs, consist merely of the thick trunks of fir-trees, into which, at intervals of every ten or eleven inches, deep notches have been cut; but these rude steps are mounted with perfect security and ease by the sure-footed Indians.