levers by which the valves were opened and closed to the beam with strings, in such a way that the beam itself performed his work without detriment to the motion of the engine, and greatly to the convenience of the ingenious boy. As soon as the contrivance was observed, the strings were removed, and a bar called a plug-frame was introduced in its place.

Surtzer, the author of a work on Hydraulics, published in 1729, speaks in terms of high praise of Newcomen's atmospheric engine. "It is," he says, "the beautifullest and most useful engine that any age or country ever yet produced." And this praise was at the time well deserved. Desagulier, however, attributes the success of the contrivance more to chance than to knowledge and skill. "After many laborious attempts," he says, "they succeeded in making their engine work; but not being either philosophers to understand the reason, or mathematicians enough to calculate the power and proportions of the parts, they very luckily, by accident, found what they sought for." This is, at the best, an ill-natured judgment, and its truth may also be doubted. Newcomen had been in communication with Dr. Hook on the subject, and the advice he received from him is an indirect proof that he was not altogether ignorant of science. This correspondence must have been before 1703, in which year the Doctor died, so that the inventor is chargeable with both idleness and incapacity, if he had not made himself a philosopher equal to the requirements of the age in which he lived, by the time

he completed his work and obtained his patent. That he was an indifferent mathematician is probable, for the improvements subsequently made in its construction prove that the proportions of the several parts had not been calculated. With the exception of some important alterations made by Mr. Beighton in 1718, the engine remained for fifty years in nearly the same state as it came from the hand of the inventor. If this fact does not add to the reputation of Newcomen, it is at least a bar to the reproaches of his contemporaries. Nor must it be forgotten that we are indebted to him for the practice of condensing steam by an injection of cold water, and for the expulsion of the condensing water and air by the injection of steam-which processes are still adopted by the engineer and for the introduction of the beam, as well as the general form of the engine.

Some improvements, both in arrangement and construction, were made in 1759, by James Brindley, the engineer who designed and constructed the Duke of Bridgewater's canal. In 1772, Smeaton directed his attention to the engine, and with great care calculated the proportions of its parts; and, by his skill, perseverance, and genius, it remained in use long after Watt had made his first brilliant discoveries, and established his reputation as the Archimedes of the Christian era.

Thus, by slow degrees, was this wondrous agent gradually prepared, ripening from a mere philosophical toy into a useful and important instrument of industry. Although we are still upon the very borders of the subject-the chief im

provements in the steam-engine having been effected by the individual whose career forms the subject of our next chapter-it is interesting to cast our eye back to the days of Hero, and to contemplate the successive struggles and achievements of the inventors who followed in his track. In such a retrospect, the wondrous powers of the human mind are effectually displayed. The instinct of the bird that builds its nest-of the bee that constructs its cell-is wonderful indeed; it is, however, stationary and stereotyped while man's intellectual powers are ever varying, and advancing from one triumph of skill to another. Is it likely, we may ask, with an eloquent writer, that a being so endowed is to sink into annihilation in a few short years-that the immaterial agent which works within, and employs eyes and fingers only as instruments for doing its incalculably various tasks, should cease to exist when it leaves its present dwelling and lays aside its present tools? No, it must live when all the material triumph, which science has achieved— when every object that now delights the senseswhen all the productions of art throughout the world, and all its mountains, rivers, and seas, shall have passed away. The thought of such an endless existence is, indeed, an overpowering one. the reader ever pondered it aright? Well might the great Teacher ask the question, "What shall a man give in exchange for his soul?" There is nothing that he can give.

Has

CHAPTER III.

THE EARLY LIFE AND PURSUITS OF JAMES WATT.

THE slow and halting steps of scientific discovery and mechanical invention, from the time of Hero, the Alexandrian, to the commencement of the eighteenth century, are strongly contrasted with the bold and majestic strides which have since distinguished their progress. With difficulty the painfully elaborated thought gave birth to an isolated fact, which neither the discoverer nor his compeers had invention, skill, or knowledge enough to apply to any effective practical purpose. As a twilight, however short, is always the transition between night and day-for darkness and light cannot come into contact so indistinct perceptions and feeble efforts are the conditions which must intervene between ignorance and knowledge, indolence and enterprise, whether in individuals or societies. We are not, then, surprised that the sixteenth and seventeenth centuries should have been spent by the most intelligent and observing scientific minds of Europe in the discovery of the pressure of the atmosphere and the elasticity of steam; nor that the inventive faculty of the mechanist should have been ex

hausted in awkward, ineffective attempts to apply them as motive forces in mechanical arrangements. Far more strange and anomalous would it have been, if, after such a lengthened period of mental inaction and blindness, dependence on authority, and attachment to sensual pleasures, as distinguished the despotic rule of the Roman Church in England before the Reformation, one or more great minds had made the discoveries and effected the revolution which distinguished the eighteenth century. If Watt had lived in the days of Worcester, the same benefit would not have been received by society from his vast intellectual power and indomitable perseverance. God, in the course of his providence, usually effects his designs by slow, often by imperceptible means, and always introduces his agents at the times most suited to the development and application of their powers. In no secular event is this more remarkably exhibited than in the state of science and the mcchanical arts, as well as the growing wants of society, when Watt made his appearance as a philosophical investigator and inventive mechanician. The result of his labors established not only a new scientific era, but also an improved commercial and social condition, destined by God to accomplish important designs in the arrangements of his providence.

Speaking of Mr. Watt, Lord Jeffrey says: "This name, fortunately, needs no commemoration of ours; for he that bore it survived to see it crowned with undisputed and unenvied honors, and many generations will probably pass away