long chapter of economic history. I think the statement on this point in the body of my article is essentially true. Nor can I agree with my critic that we do not need to stimulate the tendency in this country in favor of state interference. I think that we are prevented to-day from undertaking certain great reforms by the general feeling in the community at large that individual instead of state effort should be relied upon in all cases to secure economic advance. To present the conclusion of the matter in a word, it is perfectly possible, of course, for the state to interfere in such a way as to discourage and destroy industry. All of us agree to that. It is, on the other hand, we claim, perfectly possible for the state to interfere in such a way as to promote and create industrynay, more: it must be continually interfering to do this, otherwise progress would stop and retrogression set in. Such action is economic in character, and the systematic investigation and discussion of it find their proper place in the science of economics. E. J. JAMES.

CLIMATE AND COSMOLOGY.

No one should take up Mr. Croll's essays for light reading; not because his writing is not sufficiently clear and concise, but because the interaction of the many direct and indirect causes concerned in his physical theory of terrestrial climate requires so involved a conception that the reader must go slowly to possess himself of it fully. This is shown by Mr. Croll's frequent and just complaint that his critics fail to apprehend his points.

The essence of his argument is, that, during a time of great eccentricity of the earth's orbit, the hemisphere, having its winter in aphelion, will be subjected to glacial conditions as a result of the various physical processes then brought into play. Prominent among these is the diversion of the warm equatorial ocean-currents into the nonglaciated hemisphere by means of the increased velocity of the trade-winds in the glaciated hemisphere, and their extension well across the equator, on account of the then great difference between polar and equatorial temperatures on which they depend. For example: if our hemisphere be the cold one, it is supposed that the north-east trade would gain in strength, and extend south of the equator, so far as to carry all the equatorial currents into the southern hemisphere.

66 The warm water being thus wholly withdrawn from the northern hemisphere, its temperature sinks enormously, and snow begins to accumulate in temperate regions."

Discussions on climate and cosmology. By A. CROLL. New York, Appleton, 1886. 12°.

If this fundamental point be conceded, we may as well grant all that follows it; but it cannot be conceded for a moment. Our north-east trade will doubtless be strengthened, in winter at least ; but so will the prevailing westerly winds of our temperate latitudes. Moreover, the heat equator, along which the trade-winds meet, will not migrate far south from the geographic equator, on a planet with as short a year, as moderately inclined an axis, and as large an equatorial water-surface, as ours especially when the southern summer is moderated by coming in aphelion, and again, especially in the Atlantic, as long as the coast-line of Africa allows so much ccol South Atlantic water to reach the central torrid zone, and as long as Cape San Roque stands in the way and turns so much of the equatorial current northward.

No sufficient reason, therefore, appears for granting the north-east trade strength and area enough at such a time to keep warm water out of the North Atlantic, summer and winter; and in this ocean, at least, the general eddy-circulation would be continued much in its present form, all the more because whatever aid is given by gravity to the wind-made currents is then intensified. The broad drift of waters that crosses the North Atlantic from our shores to Europe would then be accelerated by the stronger winter winds; it would then, as now, divide opposite Spain; and the northern branch on which the moderate temperature of north-western Europe so largely depends would then, as now, be supplied largely with water that had been warmed while crossing the equator. As long as this source of warmth prevails, a winter's snows in far aphelion cannot overreach the succeeding summer's melting in close perihelion, without the assistance of geographic or other changes which Mr. Croll deems unessential.

In view of such objections as this, it seems to me that Mr. Croll decidedly overstates the security of his position in saying that his theory contains no hypothetical elements.' The quantitative estimation of his causes is certainly often hypothetical.

Until more is known, not only about winds and currents, but also about the behavior of the atmosphere towards radiant energy, and the part played by dust over the land (of which Mr. Croll takes practically no account) as well as by vapor over the ocean, there must naturally be much of hypothesis in the discussion of terrestrial temperatures.

Readers of Dr. Croll's work should examine also a critique by Woeikof in a recent number of the American journal of science.

W. M. DAVIS.

MANUAL TRAINING.

IN the wave of enthusiasm for manual training which is now passing over this land, it is very difficult to get together the results of experience, and still more difficult to determine whether the plans which work well in one place are adapted to another. Therefore every honest record of a working organization is to be welcomed. Even when the opinions of a writer are not accepted, his statement of facts should receive attention.

These remarks apply to the volume on manual training, which has lately been published from the pen of Charles H. Ham. The work has its practical, its historical, and its philosophical aspect. In the first hundred pages there is an elaborate account of the Chicago manual training school, which was founded in 1883 by the Commercial club, an association of merchants, who, after a discussion of How to increase the supply of skilled labor,' pledged the sum of one hundred thousand dollars for the support of an industrial school. A large building has been constructed, and instruction is given in carpentry, wood-turning, founding, forging, and in the making of machinery. The various laboratories devoted to these purposes are described, but the experience of two years is, of course, too limited to be very significant. The general principles of the establishment seem to be in close accordance with the well-known views of Professor Runkle of Boston, and of Professor Woodward of St. Louis.

In reading this volume we have been impressed with this danger, - that, in giving emphasis to the value of manual training, the worth of mental training will be overlooked. James Russell Lowell, in a recent speech, wittily said that not only are those studies of value which make bread-winning easier, but also those which will make every morsel of bread taste the sweeter.

The author of the book before us declares at the

beginning that it is a theory of the Chicago school, that "in the processes of education the idea should never be isolated from the object it represents." Indeed! Can this be so? Are abstractions' to have no rights which the school is bound to respect? How about the idea of number, of form, of quantity, of force? Probably the author did not see the bearing of his remark; but he repeats it in these words: " Separated from its object, the idea is unreal, a phantom." This is very different from the saying of Sir Humphry Davy, that there is nothing so prolific in abilities as abstractions. Believing as we do in the great importance of manual training, believing

Manual training, the solution of social and industrial problems. By CHARLES H. HAM. New York, Harper, 1886. 12°.

that every living being will be happier if he can skilfully use his fingers in some useful art, we regret to see the advocates of dexterity defend their views by wrong arguments and defective logic.

THE Johns Hopkins university circular for May states that Professor Rodolfo Lanciani of Rome will give a course of lectures on Roman archeology during the next academic year. He has been for some years professor of archeology at the Roman university, and inspector of excavations for the city, and is also one of the leading members of the archeological commission of Rome, and of the Pontifical archeological society. Though still quite young, he is one of the first authorities on Roman archeology, and has followed with greater care than any other archeologist the important excavations that have laid bare, from 1871 to 1886, so considerable a part of the ancient city. In 1880 he published "I comentarii di Frontino intorno le acque e gli aquedotti. Sylloge epigrafica aquaria," a learned work crowned by the Academy of the Lincei. This is but a small part of a great work to which he has been devoting years of research, a complete topography of the ancient city of Rome, critical and historical. Professor Lanciani has contributed important papers to the Bull. della comm. archeologica, to the Notizie degli Scavi, and other archeological periodicals, besides separate works, such as 'Iscrizioni dell'Anfiteatro Flavio' (1880).

The recent invention by Dr. J. O'Dwyer of New York, of a new method of treatment to take the place of the dreaded recourse to tracheotomy in diphtheria and membranous croup, bids fair to be of the greatest importance. His method does away with cutting-instruments entirely, and consists simply in the insertion of a tube of peculiar shape between the vocal cords, thus permitting the ingress of air into the trachea. The results already reached by this intubation treatment compare very favorably with those from tracheotomy, as regards the saving of life; and if, on extended trial, they are borne out, the invention will be ranked with the more important ones of the century, in medicine.

Mr. S. Hertzenstein of the Zoölogical museum of the Academy of sciences, St. Petersburg, Russia, is endeavoring to prepare schemes for public museums in Russia, to be promoted by the authorities. He would be grateful for any reports of American museums, especially such as relate to their organization rules or plan of operations. Any such may be mailed to him direct, or may be addressed to him, under cover, to the Smithsonian institution, Washington.

FRIDAY, JUNE 4, 1886.

COMMENT AND CRITICISM.

IN A RECENT NUMBER of the Revue internationale de l'enseignement, M. Breal, who has written before on educational topics, has an essay on the methods of acquiring foreign languages. Among some old considerations of value, he adds the less well-known remark, that, when a person goes to a foreign country to learn the language,' he rarely succeeds. But if he goes to pursue some definite profession or business, M. Breal suggests banking at Frankfort, the book-trade at Leipzig, and brewing at Munich, among others,

:

then he acquires the language very rapidly as well as very thoroughly. The reason for this is plain enough it is the substitution of natural for scholastic methods. And nature, being the better teacher, comes out ahead. In the former case, dictionaries and grammars figure largely; while, in following M. Breal's suggestions, the phrases of ordinary conversation, as well as the terminology of some particular calling, become part of the student's daily experience from the first. The hint is a valuable one, and it might save time and money, to say nothing of a discouraged spirit, to the numerous young men and women who go to Germany, France, and Italy each year to learn the language.'

IN THE DEATH, on May 16, of the aged German historian, the world has lost a scholar who has done as much as, if not more than, any one else for the extension of scientific method, and for the application to history of those rules and tests which mark the nineteenth century as pre-eminently the era of science. Born in 1795, when the reign of terror was hardly passed, and when the metaphysical notions as to the theory of the state and the rights of man which had been formulated by Bodin, Grotius, Montesquieu, Voltaire, and Rousseau, were finding their logical outcome in anarchy, Ranke grew up in a period of transition. The wave of constitutionalism was gathering a force to which even the reaction from the revolutionary excesses of the commune, aided by the holy alliance, could be but a temporary check. No. 174.-1886.

With a genius that detected the chain of causation amid a complicated mass of detail, with an exactness and an accuracy that made even the smallest event of importance, and with a power of lucid, graphic statement which attracted and interested while it instructed, Ranke was born a scientific historian. He appreciated to the full the meaning of the contemporary development, but with true historical instinct he turned to the elucidation of that previous period of transition from feudalism to absolutism which is the key to the history of western Europe in the fifteenth, sixteenth, and seventeenth centuries. In this field he was the acknowledged master. In addition to his own magnificent labors, we owe to Von Ranke the seminarium, that peculiarly scientific department of university work. And it is from him that Waitz, Giesebrecht, Von Sybel, George Bancroft, and a host of lesser historians have drawn their inspirations.

FABRY'S AND BARNARD'S COMETS, the two that have been with us since last December, have now disappeared from view in the northern hemisphere. Very few astronomers appear to have seen these comets under the most favorable circumstances. Mr. T. W. Backhouse, however, reports that on April 26 he followed the tail of Fabry's comet to a distance of thirty-eight degrees; and Barnard's comet he found on May 1 had two tails, the principal one four and a half degrees in length. To replace these comets we have three new ones discovered by Mr. Brooks, on April 27 and 30, and May 22, respectively. They are all fairly bright for what are called 'telescopic' comets. The calculated elements show that the first reaches its nearest point to the sun on June 6, and is increasing slightly in brightness: the second comet is decreasing in brightness, having passed its perihelion on May 4.

HEALTH OF NEW YORK DURING APRIL.

THE total population of New York on April 1 was estimated at 1,428,898, and is believed to be increasing at the weekly rate of 799.

The total number of deaths from all causes was 2,965, or about 99 each day. Comparing this with