the clergy, are become more staid; perhaps their characters are improved, for I hear of fewer stories to their discredit. The first time I was invited to the Borgheses' in 1836, was on a Sunday evening, and the first thing I saw when I entered was seven Cardinals, four at one table, three at another, with their red skull-caps and pieds de perdrix, playing at cards (whist). Similar exhibitions I witnessed all the season through, there and elsewhere. But this year I have not seen a single Cardinal at a card-table.'

The higher clergy of the Established Church of England have similarly abandoned whist. The last prelate who was in the habit of playing, and played the old game well, was the learned and eminently orthodox Bishop of Exeter, Dr. Phillpotts.

Paris, the Paris of the Second Empire, was no longer, in 1851, what monarchical Paris had appeared in 1838:—

'It was another atmosphere. Old times were forgotten; the old manners gone. And what is to come in their place? Paris is externally the most magnificent capital in Europe, and is becoming daily more brilliant and attractive. But where are the old salons, — their grace, their charming and peculiar wit, their conversation that impressed its character upon the language itself, and made it, in many respects, what it is?"

His Journal and Letters during his last visit to England abound, as usual, with proofs of his insight into character. He struck up a close intimacy with Sir Edmund Head, and it is to him that he is most communicative of his impressions of their common friends, which are almost uniformly just. Thus, what struck him at once in Sir George Lewis was his instinctive fairness:

'He was singularly able and willing to change his opinion when new facts came to unsettle his old one. He seemed to do it too without regret. . . . I remember I used to think he had the greatest respect for facts of any man I ever saw, and an extraordinary power of determining from internal evidence what were such.

'How striking it is that two such scholars as he (Lewis) and Gladstone should have made such capital Chancellors of the Exchequer.'

To a letter of his after his return home, describing the excellent effects of the Prince's visit to the United States in 1860, Sir E. Head replies :—

'The views which you express with reference to the effect of the Prince's visit are, I believe, quite correct. I have taken measures for letting the Queen see such portions of your letter as bear directly on the benefits likely to accrue to both countries, and I hope you will not think me indiscreet in doing so.'

He

He is as plain-spoken as could be wished about his own country:

Our politics are in a state of great confusion. As the elder Adams said to me, when he was eighty-nine years old, about the politics of the State of New York for seventy years previous," they are the Devil's incomprehensibles."'

This was in 1858, before the commencement of the civil war, which he declared at once must be fought out. In April 1863, he writes:

'Whatever awaits us in the dark future depends, I believe, neither on elections nor speeches nor wise discussions, but on fighting. I have thought so ever since the affair of Fort Sumter, and fire cannot burn it out of me.'

The death of Prescott, January 27, 1858, although neither sudden nor unexpected, was a severe shock. Two months after the event he writes to his wife's niece, Mrs. Twisleton: I do not get accustomed to the loss. Indeed, something or other seems to make it fall afresh and heavier almost every day.' At the request of the family he immediately set about the Life of Prescott, the publication of which, from circumstances connected with public affairs, was delayed till 1863. He was then seventy-two, an age at which he thought it prudent to give up authorship; but his mental powers were unimpaired, and till within a few days of his death, at seventy-nine, his principal enjoyments were derived from literary conversation or from books. His favourite reading in the decline of life was biography. He died on the 26th of January, 1871. On the preceding New Year's Day he was found reading the Life of Scott' for (as he said) the fourth time; and on being asked to recommend a subject for reading, Take Boswell,' he said, then Southey's "Cowper," the Lives of Mackintosh, Scott, Southey, and so on; the memoirs are so rich.' If the same request were made to us, we should say: Take Ticknor; the memoir is so rich, the tone and spirit are so good. No matter what your peculiar taste in this style of composition: no matter what your range of acquirement: rest assured that you will rise from the careful perusal of his journals and correspondence with a lively sense of self-satisfaction--amused, instructed and (we will venture to add) improved.

ART.

ART. VI.-1. Lectures on some Recent Advances in Physical Science. By Professor P. G. Tait, Professor of Natural Philosophy in the University of Edinburgh. 1876.

2. On Geological Dynamics. By Sir William Thomson, LL.D., F.R.S. Transactions of the Geological Society of Glasgow,' 1869.

3. On Geological Time. By Sir William Thomson, LL.D., Geological Society of Glasgow. 1868.

4. Sur le Ralentissement du mouvement de Rotation de la Terre.. Par M. Delaunay. Paris, 1866.

5. Climate and Time. By James Croll. Survey of Scotland.

London, 1875.

H.M. Geological

6. Principles of Geology. By Sir Charles Lyell. 14th Edition. London, 1875.

A

SHORT time ago Sir William Thomson took occasion, at a meeting of the Geological Society of Glasgow, to make a somewhat startling statement. He said that the tendency of British popular geology was, at the time he spoke, in direct opposition to the principles of natural philosophy.

So strong an opinion expressed by the man who is, perhaps, foremost in this country in applied mathematics and natural science, naturally attracted great attention, and it is not toomuch to say that in the six years which have since elapsed a very great change has taken place in the views of those best able to form an opinion on the subject of Sir William Thomson's animadversions.

Whether or not we are correct in saying that such a changehas actually taken place in educated public opinion it is the object of this paper to show; but we may at least affirm at the outset, without fear of contradiction, that a very smart conflict has been raging on the subject in the scientific world. The opposing forces are the geologists and the mathematicians. There has been hard hitting on both sides, and no quarter given. Of late the mathematicians have brought up their reserve, a contingent of natural philosophers, who have done good service. The latest intelligence from the seat of war speaks of a suspension of hostilities. The mathematicians will make no concessions, but the geologists appear likely to abate somewhat of their high demands. There is even some talk of an amalgamation of the opposing armies. In plain English, there has been a dispute as to the age of the world. Geologists. declared that the centuries of its duration could only be denoted by an array of figures so large as to paralyse the reasoning faculties and convey no definite impression to the mind. Other

branches

branches of science have shown cause for attributing to the solar system a limit of duration, vast indeed, but not absolutely inconceivable.

To those whose interest in such matters is literary rather than scientific, the progress of such a controversy is often very entertaining. It is true that the actual battles take place in places beyond our ken, generally at meetings of scientific societies, where the orators have it all their own way and confound their adversaries ;-till the opposition society meets. But though the philosophers retire for fighting purposes, and do battle in the clouds with weapons, phrases, and formulæ, that we cannot understand, they always come down again to earth to proclaim their victories or palliate their defeats. Once they come down, and we catch them with pens in their hands, the outsiders have their turn.

It is not, however, in the great books of Darwin, Huxley, Lyell, Helmholtz, Tait, or Thomson, that we may seek food for amusement. In these works every thought is in full dress and every phrase decorous. But there is another sort of literature in which we see the great men, so to speak, with their coats off. The Proceedings' of the learned societies. where the real fighting goes on are full of entertainment. Students of human nature need no further proof that though every man may not be a philosopher, every philosopher is. certainly a man. With what frank enjoyment they fight! With what irony-what sarcasm they annihilate their foes! It must, however, be confessed that sarcasm is not, as a rule, the strong point of the learned. The editor of a Northern newspaper of our acquaintance was one day speaking in terms of praise of his sub-editor-The brilliancy of yon young man,' said he, is surprising; the facility with which he jokes amazes. me. I, myself, am in the habit of joking, but I joke with difficulty.' We have observed the same peculiarity among other learned persons. They joke, but not with ease.

Most of the books which we have prefixed to this paper contain their authors' thoughts polished ad unguem. It would not be fair to judge of the opinions of the scientific persons we quote by any other standard than that which they have themselves carefully prepared; but yet we cannot refrain from entertaining a preference for the rough-and-ready, hard-hitting pamphlets, lectures, 'proceedings,' inaugural addresses, and the like, from which almost, without exception, these works havebeen compiled. For example, Mr. Croll's work on Climate and Time is everything which a scientific work should be that requires deep research and laborious thought, combined with

the

the boldest generalisation; but it is a digest of some five or six and thirty papers contributed to scientific magazines and periodicals during several years. Mr. Croll gives a list of his papers at the end of his volume. But though it is most convenient to see the whole before us at a glance, and to have them all under our hand or on the library shelf, yet we acknowledge that while thinking over Mr. Croll's volume, for the purposes of this review, we found ourselves again and again going back to the pages of the 'Reader' and the Philosophical Magazine,' in which we first made acquaintance with them. It may be prejudice in favour of old acquaintances, but we liked them better before. Digressions, perhaps, are cut out; some little rash speculation quietly withdrawn; some hit at an opponent suppressed; but they do not always command the same ready assent, or appear so interesting as they did in their old form.

These remarks do not apply to Professor Tait. His lectures now before us, from their nature, belong to the class of composition for which we avow our predilection. They were delivered extempore to a scientific audience, and printed from shorthand notes. They lose nothing of their vigour, to use an expression of Lord Macaulay, by translation out of English into Johnsonese. We are allowed to seize the thought in the making, and if it loses anything in grace, the loss is more than counterbalanced by power.

Those who wish thoroughly to understand the subject of this paper should study Professor Tait's lectures on the sources of energy, and the transformation of one sort of energy into another. Matthew Arnold's phrase, 'let the mind play freely round' any set of facts of which you may become possessed, often recurs to the mind on reading these papers. There is a rugged strength about Professor Tait's extempore addresses, which taken together with their encyclopædic range, and the grim humour in which the professor delights, makes them very fascinating. They have another advantage. Men not professionally scientific find themselves constantly at a loss how to keep up with the rapid advance which has characterised recent years. One has hardly mastered a theory

when it becomes obsolete. But in Professor Tait we have a reporter of the very newest and freshest additions to scientific thought in England and on the Continent, with the additional advantage of annotations and explanations by one of the most trustworthy guides of our time.

We propose to discuss the books and papers whose titles are prefixed to this article, in so far as they throw fresh light on the

probable