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health when a child, he was able to attend the public school at Greenock only irregularly and at intervals; so that much of his elementary instruction was received at home. His mother taught him reading, and his father writing and arithmetic; and in his confinement to the house, of which his almost constant indisposition was the cause, he acquired those habits of inquisitiveness and precocious reflection so often observed in feeble-bodied children. A gentleman one day calling upon his father, observed the child bending over a marble hearth with a piece of coloured chalk in his hand. Mr Watt," said he, "you ought to send that boy to school, and not allow him to trifle away his time at home." "Look how my child is employed before you condemn him," replied the father. The gentleman then observed that the child had drawn mathematical lines and circles on the hearth. He put various questions to the boy, and was astonished and gratified with the mixture of intelligence, quickness, and simplicity displayed in his answers: he was then trying to solve a problem in geometry.'* In this way, not by means of regular lessons, but by incessant employment on some subject of interest or other, Watt in early years acquired much of that general information for which he was in after-life remarkable. His father having, as a means of amusement, presented him with a number of tools such as are used in cabinet-work, he became exceedingly expert in handling them, and began to exhibit his mechanical taste in the fabrication of numerous toys, among which is mentioned a small electrical machine, with a bottle, probably for a cylinder.

An anecdote related of him when he was about fourteen years of age, indicates the extreme restlessness and activity of his mind as a boy. Once having accompanied his mother on a visit to a friend in Glasgow, he was left behind on her return. The next time, however, that Mrs Watt came to Glasgow, her friend said to her: "You must take your son James home; I cannot stand the degree of excitement he keeps me in; I am worn out for want of sleep. Every evening before ten o'clock, our usual hour of retiring to rest, he contrives to engage me in conversation, then begins some striking tale, and, whether humorous or pathetic, the interest is so overpowering, that the family all listen to him with breathless attention, and hour after hour strikes unheeded.' This wonderful faculty of story-telling, which robbed the Glasgow lady of her sleep, Watt preserved throughout his life to a degree unparalleled perhaps except in Sir Walter Scott.

As he advanced into youth, Watt began to occupy himself with the sciences. The whole range of physics had attractions for him. In excursions in all directions from Greenock, and especially to the banks of Loch Lomond, he studied botany, entered eagerly into the geological speculations then beginning to awaken interest, and

* Arago's Life of Watt.

collected traditions and ballads-all with equal enthusiasm. At home, during his hours of less robust health, he devoured books on chemistry and general science, among which was Gravesande's Elements of Natural Philosophy. Medicine, surgery, and anatomy obtained their share of his attention; the detailed descriptions of diseases given in medical works were familiar to him; and he was one day detected carrying into his room the head of a child recently dead, which he had managed somehow to procure, with the intention of dissecting it. In short, by incessant reading and mental activity, he had, before he entered on his nineteenth year, acquired and digested a vast mass of miscellaneous scientific information.

Whether from the prevailing bent of his genius towards mechanical contrivance, or from some other cause connected with the nature of his father's trade in Greenock, the profession which Watt chose was that of a mathematical and nautical instrument maker. To learn this art, or rather to perfect himself in it, he went to London in 1755, and placed himself under Mr John Morgan, an instrumentmaker in Finch Lane, Cornhill. Thus, says M. Arago, 'the man who was about to cover England with engines, in comparison with which the antique and colossal machine of Marly is but a pigmy, commenced his career by constructing with his own hands instruments which were fine, delicate, and fragile—those small but admirable reflecting sextants to which navigation is so much indebted for its progress.' After a residence of little more than a year in London, his continued feeble health obliged him to return to Scotland, where, in accordance with his own wishes and the advices of his friends, he commenced business as a mathematical instrument maker in Glasgow. The date of his settlement in this city, where he was afterwards to work out some of his greatest triumphs, was 1757, when he had just passed his twenty-first year. At first, he experienced considerable opposition, and a great deal of annoyance-one of the privileged corporations of the town regarding him as an intruder, and not entitled to practise the business which he professed, at that time a comparatively rare one in Scotland. Various means were tried to soothe down the offended parties, but without effect; they would not even allow the young tradesman to set up a workshop on the smallest scale. At length, apparently through the exertions of the friends of his family, he was rescued from the dilemma by the authorities of the university, who gave him a convenient room within their precincts, and conferred on him the designation of Mathematical Instrument Maker to the College of Glasgow, a proceeding which was sufficient to quash all corporation enmity. In the workshop thus afforded him, Watt continued for a number of years to pursue his trade of making sextants, compasses, &c. for which articles he found customers both within and without the walls of the university. 'There are still in existence,' says M. Arago, some small instruments which were at this time made entirely by Watt's own hand,

and they are of very exquisite workmanship. I may add that his son has lately shewn me some of his first designs, and that they are truly remarkable for the delicacy and precision of the drawing. It was not without reason that Watt used to speak with complacency of his manual dexterity.' This, as we have seen, was a gift which seemed to be hereditary in the family.

At the time when Mr Watt took up his residence in Glasgow, there was a cluster of eminent men gathered together within the university such as is rarely to be found. Adam Smith was Professor of Moral Philosophy; Robert Simson of Mathematics; the illustrious Black filled the chair of Chemistry; and Mr Dick, who, though less known to fame, is said to have been a man of great powers, held the professorship of Natural Philosophy. Robison, afterwards so celebrated for his attainments in physical science, which he displayed as a professor both in Edinburgh and Glasgow, was then a student. Watt's position within the college brought him into contact with all these able men; and the shop of the young mathematical instrument maker soon became a lounging-place for both professors and students—the former of whom found in him a man equal to themselves in acquirements, and of a remarkable originality of mind; the latter, a good-natured and willing assistant in their speculations and researches in physics. 'I had always,' says Professor Robison, referring to those days when he first became acquainted with Watt, 'a great relish for the natural sciences, and particularly for mathematical and mechanical philosophy. When I was introduced by Drs Simson, Dick, and Moor to Mr Watt, I saw a workman, and expected no more; but was surprised to find a philosopher, as young as myself, and always ready to instruct me. I had the vanity to think myself a pretty good proficient in my favourite study, and was rather mortified at finding Watt so much my superior. Whenever any puzzle came in the way of us students, we went to Mr Watt. He needed only to be prompted; for everything became to him the beginning of a new and serious study, and we knew that he would not quit it till he had either discovered its insignificancy or made something of it. He learned the German language in order to peruse Leopold's Theatrum Machinarum. So did I, to know what he was about. Similar reasons made us both learn the Italian language. When to his superiority of knowledge is added the naïve simplicity and candour of Mr Watt's character, it is no wonder that the attachment of his acquaintances was strong. I have seen something of the world, and I am obliged to say I never saw such another instance of general and cordial attachment to a person whom all acknowledged to be their superior. But that superiority was concealed under the most amiable candour, and a liberal allowance of merit to every man. Mr Watt was the first to ascribe to the ingenuity of a friend things which were nothing but his own surmises, followed out and embodied by another. I am the

more entitled to say this, as I have often experienced it in my own

'case.'

This and similar accounts enable us to figure Mr Watt during his early residence in Glasgow-a young, amiable, and ingenious man, a great favourite with professors and students, occupied during the greater part of the day in his workshop, but constantly engaged in the evening in some profound or curious question in mathematics or physical science; quite aware of all that was going on in the scientific world, and taking an interest in all new discoveries, particularly those of his friend Dr Black in chemistry. As a remarkable instance of the extent of his theoretical research, and of his perseverance in whatever undertaking struck his fancy, it is mentioned that although he had no ear for music, and could never, all his life, distinguish one note from another, or derive pleasure from any musical performance, he astonished all his friends by constructing an organ, which, besides exhibiting numerous ingenious mechanical improvements, was particularly admired by musicians for its greatly superior powers of harmony. His only guide in this difficult achievement must have been the Harmonies of Dr Smith of Cambridge, a work treating of some of the extreme problems of acoustics, but so profound and obscure, that few persons in the kingdom could have understood a page of it.

In the year 1763, Mr Watt married his cousin, Miss Miller, who is described as a person of much wit and accomplishment, with great sweetness of temper. At the same time he removed from his apartments in the college to a house in town, in which he continued his profession, enlarging it, however, so as to include engineering. He accordingly began to be consulted in the construction of canals, bridges, and other works of large dimensions requiring science and skill. In the midst of these engineering avocations, a circumstance occurred which exercised a more important influence upon his career than any of them. In the winter of 1763-4, Mr Anderson, who had succeeded Dr Dick as Professor of Natural Philosophy, and who is still remembered as the founder of the Andersonian University, Glasgow, finding that a small model of Newcomen's steam-engine, which he had among his apparatus, would not work, sent it to Mr Watt for repair. The subject of steam-machinery had several times before come under Mr Watt's notice. His friend Mr Robison had, in 1759, broached to him the idea of applying steampower to wheel-carriages; and in 1761-2, he had occupied himself with various experiments on a Papin's Digester, with a view to measure the force of steam. These discussions and experiments, however, terminated in no particular result; and it was Professor Anderson's model of Newcomen's engine that begot in Watt's mind the germ of those ideas respecting the use of steam-power which have led to such gigantic consequences. As Newcomen's engine represents the point of progress to which steam-machinery had been

brought before Watt applied himself to the subject, this seems the proper place for introducing a sketch of the history of steam-power up to that period. The little black model on the instrumentmaker's table was the condensed epitome, as it were, of all that the world knew of steam-power before that time; in the brain of the young newly-married instrument-maker, bending by candlelight over the model, lay, as yet undeveloped, all that the steam-engine has since become.

HISTORY OF THE STEAM-ENGINE BEFORE THE TIME OF WATT.

Steam, or, as they called it, 'water transformed into air by the action of fire,' was of course known to the ancients, and was used for various ordinary purposes in the arts. The first description, however, of the application of steam as a mechanical power occurs in the writings of Hero, a Greek of Alexandria, who lived in the third century before Christ. This writer, whose attainments in science were very great for his age, describes a toy called the Eolipile, the purpose of which is to produce a rotatory motion by the action of steam. The best familiar illustration of the appearance of such an apparatus in one of its simplest forms, would be one of those turnstiles, with four horizontal spokes, which are sometimes placed in by-paths. Were one of these revolving stiles made of iron, and hollow throughout, with a hole in the corresponding side of each of the spokes, and were the upright shaft to be fixed into a socket beneath, entering a boiler, then the steam rushing up the shaft and along the four spokes, would hiss out in four jets at the side openings, and the whole would, owing to the force of reaction, whirl round in the opposite direction. Here, therefore, nearly two thousand years ago, we find steam applied to produce a rotatory motion. By connecting the simple rotatory apparatus above described with additional machinery, mills could be driven, and other important mechanical effects produced. Indeed, the construction of rotatory steam-engines has, in recent times, occupied much attention; and, under the name of Barker's Mill, the principle of the Eolipile has been turned to account-the reaction caused by the escape of steam having been made in some instances to do the work of six or eight, or even fifteen horses. The principle of the Eolipile, however, and of the rotatory engines which are modifications of it, is evidently different from that of steamengines usually so called, in which the power consists not in the mere reaction caused by steam violently escaping into the atmosphere, but in the prodigious expansive force of steam itself. Water, when converted into steam by the application of heat under the ordinary pressure of the atmosphere, occupies, it is well known, 1728 times its original bulk; in other words, a cubic inch of water is, on its conversion into steam, expanded so as to fill a space of a cubic foot. This is nearly eight times as great as the expansive force of