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 had made something of it.

"On one occasion, the solution of a problem seemed to require the perusal of Leupold's "Theatrum Machinarum," and Watt forthwith learned German. At another time, and for a similar reason, he made himself master of Italian. When, to the superiority of knowledge which every man confesses in his own line, is added the naive 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 am obliged to say, that I never saw such another instance of general and cordial attachment to a person whom all acknowledged to be the superior. But the superiority was concealed under the most amiable candour, and liberal allowance of merit to every man. Mr. Watt was the first to ascribe to the ingenuity of a friend things. which were often nothing but his own surmises followed out and embodied by another. I am well entitled to say this, and have often experienced it in my own case."

No better proof of the energy and perseverance with which Mr. Watt pursued all his studies can be given than the success with which he constructed an organ. A natural infirmity denied him the appreciation of sounds -he could not, it is said, distinguish one note from another. That in the construction of the

instrument he should have made many mechanical improvements might be expected, but it is really astonishing that its harmonic qualities were improved, and that, by the phenomena of the beats of imperfect consonances, he found out the temperament assigned by a master of art.

CHAPTER IV.

WATT'S EARLY EXPERIMENTS UPON STEAM AND THE STEAM ENGINE.

WE have now arrived at the period when the attention of Watt was first directed to the serious study of steam and the steam engine. Among the apparatus in the university of Glasgow intended for the illustration of the lectures, there was a model of Newcomen's atmospheric engine. Many efforts had been made to work it, but without success; and it was at last sent by Dr. Anderson, professor of natural philosophy, and the founder of the Andersonian Institution, to Watt for repair. Upon what small and apparently insignificant causes do great events hinge! Little could the person who sent the machine in question have foreseen that in giving the order for its transmission to James Watt, he was making the first step towards the development of a series of events that were to revolutionize the commerce of the world.

The necessary alterations were made in the model, and when it was returned to its owner, it worked satisfactorily. But, in executing the

repairs, the young philosopher's attention was necessarily drawn to the structure of the engine, and the relative proportions of its parts. Many inquiries were suggested, and Watt was not the man to leave them unanswered. The hours of business he punctiliously employed in his avocations; his experiments were commenced when the workshop was closed. One subject followed another-the termination of one inquiry was but the commencement of a new one-and in each he provided himself with data upon which his inventive skill might be safely employed. He determined, as M. Arago states, the increased volume of water when it passes from the liquid state to that of vapour-the quantity of water which a given weight of coal can convert into steamthe quantity in weight of steam expended at each stroke by a Newcomen's engine of given dimensions-the quantity of cold water which must be injected into the cylinder in order to give the downward stroke of the piston a certain specified force-and lastly, the elasticity of steam at different temperatures. Although we cannot follow with minuteness the experiments he made, it is necessary that the results should be known, not only to appreciate his labours, but to understand the value of the invention to which they led him. In doing this, his own descriptions may sometimes be employed, which are the more valuable from the scantiness of his written contributions to science.

Mr. Watt wrote but little for the press, but

was happily induced by Dr. Brewster to revise a work on the steam engine, written by his deceased and much-loved friend, Dr. Robison. Of the notes he added to this work, we shall avail ourselves as far as possible, for not only are the details and results of experiments best described by those who made them, but the respect and honour universally entertained for the memory of this great man give a more than ordinary value to the few words he has left us. His thoughts, happily for mankind, were chiefly embodied in inflexible iron, which he, as it were, animated with a living force. The thoughts of Watt may be read wherever the steam engine is at work, and all that words can do is to record their history, and to teach the ignorant how they may be deciphered.

Several attempts had been made, before Mr. Watt came to the study of steam, to determine the increased volume of water when converted into vapour by heat. Sir Samuel Morland, it will be remembered, had approximated to the truth, and others had pursued the same inquiries; but with the results of the later experiments, which were probably those alone with which he was acquainted, Watt was dissatisfied. "It being evident," he says, "that there was a great error in Dr. Desagulier's calculation of Mr. Beighton's experiments on the bulk of steam, a Florence flask, capable of containing about a pound of water, had about one ounce of distilled water put into it; a glass tube was fitted into its mouth, and the joining