the mines of South America, did not take place till 1815; and in the following year a report on the subject was published in the Lima Gazette. After describing this important event, it adds, " Immense and incessant labour, and boundless expense, have conquered difficulties hitherto esteemed altogether insuperable; and we have, with unlimited admiration, witnessed the erection, and astonishing operation of the first steam-engine. It is established in the celebrated and royal mineral territory called the mountain Yaiiricoeha, in the province of Tarma; and we have the felicity of seeing the drain of the first shaft in the Santa Rosa mine, in the noble district of Pasco." They add, "We are ambitious of transmitting to posterity, the details of an undertaking of such prodigious magnitude, from which we anticipate a torrent of silver, that shall fill surrounding nations with astonishment."

It appears that the new world was principally indebted to the agency of M. François Uville for this improved era in their mining annals. This gentleman having found that a large portion of the most valuable mines in Peru was falling into decay, and in some cases totally drowned from the impossibility of draining them by manual labour, applied to Mr. Trevithick of Camborne in Cornwall, one of the patentees of the high-pressure engine. This ingenious mechanic applied himself with such extraordinary diligence to the subject, that in less than nine months the materials for as many engines were completely ready for their destination. The apparatus, which cost about ten thousand pounds, was embarked at Portsmouth in the beginning of September, 1814, accompanied by M. Uville and three Englishmen, to superintend the erection of the machinery.

Mr. Trevithick was afterwards employed as engineer to the Royal Mint established at Lima, and on his arrival in

South America, was received with such enthusiastic gratitude, that the Lord Warden proposed to" erect his statue in massive silver." The engines employed were exclusively on the high-pressure principle, and will be found under his patent in the Appendix. Indeed this appears to be the only cheap engine likely to act with an advantageous effect, the extreme rarity of the atmosphere in those elevated regions, precluding the economical use of the common atmospheric engine.

We have hitherto viewed the steam engine, when employed as a substitute for animal force, in giving motion to mills, raising of water, and a variety of other employments, all of which, however, are of a fixed and stationary nature. But some progress has likewise been made towards the application of the same power to moveable machinery, and. when constructed for this purpose it is called a locomotive engine.

The employment of an internal mechanism to impel waggons on a plane road is of very early date, but the first application of the steam engine to this purpose took place, we believe, in the Royal Arsenal at Paris, towards the close of the last century. From this time till 1802, but little progress appears to have been made in the use of this species of wheel carriage; but about the latter period, • Mr. Trevithick commenced a series of experiments on the use of the high-pressure engine for the above purpose; and this, with some improvements, has since been adopted.

When these engines were first tried, it was found difficult to produce a sufficient degree of re-action between the wheels and the track road, so that the former turned round without advancing the vehicle. This was remedied by Mr. Blenkinsop, who, when he adopted this species of conveyance, took up the common rails on one side of the whole length of the road, and replaced them with rails

which had large and coarse cogs projecting from the outside. The impelling wheel of the engine was made to act in these teeth, so that it continued to work in a rack the whole length of the road.

An engine of four horses' power, employed by Mr. Blenkinsop, impelled a carriage lightly loaded at the rate of ten miles an hour, and when connected with thirty coal waggons, each weighing more than three tons, it went at about one-third of that pace.

Mr. Blenkinsop has since stated in reply to queries put by Sir John Sinclair, that his patent locomotive engine, with two eight-inch cylinders, weighs five tons, consumes two-thirds of a hundred-weight of coal, and fifty gallons of water per hour; draws twenty-seven waggons weighing ninety-four tons on a dead level, at three and a half miles per hour, or fifteen tons up an ascent of two inches in the yard; when 'lightly loaded,' travels ten miles an hour, does the work of sixteen horses in twelve hours, and costs £400. Another person says, that the weight of this engine with its water and coals is six tons, and that it draws forty or fifty tons, (waggons included,) at four miles an hour on a level rail-way. This seems to have been a high-pressure engine of about eight or ten horses' power. But we are not informed what sort of rail-way it worked on, how long its journeys were, or what is meant by 'lightly loaded.'

The application of the steam engine to impel carriages on the public roads, has hitherto been considered as a refinement in mechanics, rather to be wished for, than a matter of reasonable expectation. It has however been stated, that a vehicle of this description is now constructing in Ireland, intended as a stage-coach, and it is added, that when loaded with a weight equal to four tons, it will be enabled to advance at the rate of fifteen English miles per hour. But it must, we think, be sufficiently apparent,

that the employment of this species of prime mover on a common gravel road, would be in the highest degree destructive, and a considerable increase in the toll would be the certain consequence.

In proof, however, that the necessity of employing an iron track-road for these vehicles is not so serious an objection as at first view might be supposed, more particularly in our mining districts, the neighbourhood of Newcastle alone, affords, within an extent of twenty-eight square miles, more than seventy-five miles fitted for this species of conveyance; and it is a well known fact, that there are many situations in which iron rail-roads might be advantageously employed, in which it would be quite impossible to open a navigable canal.

M. Dupin, whilst speaking of the immense mechanical force set in action by the steam engines of England, gives the following illustration of its amount. The great pyramid of Egypt, required for its erection the labour of above 100,000 men for twenty years: but if it were required again to raise the stones from the quarries and place them at their present height, the action of the steam engines of England, which are managed at most by 36,000 men, would be sufficient to produce the effect in eighteen hours. And M. Dupin says, that if it were required to know how long they would take to cut the stones and move them from the quarries to the pyramid, a very few days would be found sufficient.

The calculation of M. Dupin is as follows: the volume of the great pyramid is 4,000,000 cubic metres, its weight is about 10,400,000,000 kilogrammes. The centre of gravity of the pyramid is elevated forty-nine metres from the base, and taking eleven metres as the mean depth of the quarries, the total height of elevation is sixty metres, which multiplied by 10,400,000 gives 624,000,000 tons

raised one metre. Then the total of the steam engines in England represents a power of 320,000 horses. These engines, moved for twenty-four hours, would raise 862,800,000 tons one metre high, and consequently 647,100,000 tons in eighteen hours, which surpasses the produce of labour spent in raising the materials of the great pyramid.