occupations, and "those who are unscientific will have much less employment, and will be left behind in the race of life." England also will be compelled, by the necessities of human progress and the advance of foreign intellect, to determine and recognize the proper value of science as a branch of education.

The philosophy of matter is the foundation of all manufacturing arts and artistic processes; technical education, or the relations of science to manufactures, &c., can only be properly imparted upon the basis of a sufficient knowledge of theoretical science. An attempt to impart technical education without such a basis would be but a very imperfect improvement upon the present system of learning by the "rule of thumb" alone. It is true that our artisans can work and do work without scientific knowledge, but they cannot work to the greatest advantage; and it is precisely such knowledge they now so badly require. It would be difficult to state exactly how much of such knowledge should be imparted to intended workmen; but it should certainly include all the chief laws and principles of the sciences involved in their prospective employments. persons in general, who are not intending to become teachers of science, require to learn, is rather the general principles and leading facts of science, and their relations to manufactures, than a large extent of science; the entire subject is altogether too great for them.

What

It is both unnecessary and undesirable that lessons in science should be entirely of an abstruse character, abounding in scientific terms difficult to understand. All such lessons should be freely illustrated by experiments, apparatus, models, processes, diagrams, drawings, and the use of the black-board; and the difficult terms necessarily employed in them should be fully explained. By selecting many of the illustrations from the applications of science in the phenomena of the material universe, of manufactures, and of everyday life, all the fundamental laws and principles of physical and chemical science may be readily made intelligible to the meanest intellect. By this method also, the theory of science and its practical applications may be simultaneously taught in the most natural and effective manner. In all scientific lessons to practical persons, suitable technical illustrations should be freely employed. Artisans have to deal, not so much with the laws and principles of substances and forces, as with the substances and forces themselves; and men who have to deal with matter and forces require not only the forms but the tangible realities of scientific knowledge. If an attempt is made to teach pure science alone without such illustrations, workingmen and practical persons will not accept it, because they cannot perceive its application to their wants. What they specially require to be taught is, how such knowledge is applied and operates in their several occupations.

Each special manufacture usually involves the principles of

several sciences, including physics and chemistry; and therefore the employments connected with it, and the technical education relating to it, also necessarily include a knowledge and an explanation of the chief laws and principles of those sciences: for example, the manufacture and working in metals requires a knowledge of the sciences of mechanics, heat, and chemistry; the occupation of electro-plating necessitates a knowledge of electricity and chemistry; the numerous employments involving the construction or use of tools and machinery require a knowledge of the science of mechanics, and in some cases also of heat and chemistry.

The fundamental laws and principles of any particular science operate in a similar manner in all trades, and are substantially the same for all learners: for example, the same chemical and electric principles operate in the galvanic batteries of telegraphists and electro-platers, as in those of the scientific investigator; the laws of combustion are the same in a puddler's furnace as in a domestic fireplace; water boils at the same temperature, whether it be in a chemist's flask, a brewer's copper, or in a servant's saucepan; the laws and principles of science, therefore, cannot be readily subdivided to suit particular trades. With the practical illustrations, however, the case is different; they may be selected from particular occupations, manufactures, arts, processes, and substances, so as to make the lessons suitable for different classes of persons, and thus by varying the kind of illustrations the lessons may be adapted to persons of different occupations, to agriculturists, metallurgists, and others. In courses of lessons or lectures on technology, the teacher should be very careful to select as many of the illustrations as possible from the actual working experience involved in the particular trades or occupations of his audience, and in this way the highest science may be united to the meanest art. A difficulty connected with the carrying out of this plan is, technical processes are rarely well understood by professional teachers, because those processes depend so much upon practical details.

The technological teacher must know both the science of the manufacture and the details of the manufacture itself to which that science is applied; he must be able to combine theory and practice, and continually to show the relation of abstract laws and principles to technical results. He must not only know how difficult things are done, but he must also to some extent be able to do them, and thus to teach by example as well as by precept. His teaching must be full of practical applications and familiar illustrations. Such teachers are as yet almost unknown, and Faraday, in his evidence already referred to, stated that the class of men suitable for teaching science remained to be created.

This statement made by Faraday still remains true. Our Universities have not yet supplied many schools with teachers eminent

in physics or chemistry. The sudden public demand for some indefinitely understood scientific education has produced a supply of comparatively unqualified teachers, and those appointed in some of our schools have had only a book-knowledge of the subject, but little experience in making experiments, much less acquaintance with the relations of science to manufactures, and entirely without experience in original experimental research. The ignorance of some of the simplest practical scientific matters, shown by some of these otherwise educated gentlemen, has been quite astonishing, and the most charitable supposition is that they are unaware of their ignorance.

The kind of teachers required for communicating scientific instruction are not men possessed only of a book-knowledge of science, and the power of communicating it, nor even of men who have also repeated the experiments of others as described in books, but men who, in addition to all this, are familiar with the details of manufacturing operations, and have also had considerable experience in original experimental research, and thereby acquired the power of distinguishing truth from error in matters of science,-a quality of the highest value in teaching, and which cannot be acquired in any other way.

VIII. ATMOSPHERIC ELECTRICITY AND RECENT
PHENOMENA OF REFRACTION.
By SAMUEL BARBER.

WHATEVER connection may exist between earthquakes and electrical disturbance of the atmosphere-a connection remarkably substantiated during the past year-there seems little reason to doubt that there exists between the electric waves or currents and the condition of atmospheric vapour a close relation. The more we examine the various changes of cloud and mist, their multiform shapes and ever-varying tints, their changes in density, altitude, and attractive or repulsive power, the more are we convinced that a force of incalculable power and undefined extent, more subtle and scarcely less potent than that of gravitation is in constant operation upon them.

The operation to which I allude, that of electricity, both atmospheric and terrestrial, seems rather to have been studied in its exceptional manifestations, than as a force subject to law, and of vast and constant, though unobtrusive, influence. The difficulty of rendering this science deductive, in its relation to meteorology, is apparent; the collection of data and the progress of experimental research form our present basis.

VOL. VII.

R

Till something more is known, however, and known more definitely, as to the nature of cloud and fog constituents, we can scarcely expect much progress in this department; and I would commend the subject to aëronauts and microscopists. Mr. Proctor, in an interesting paper on the subject of rain,* quotes De Saussure, Kamptz, &c., against Sir J. Herschel and Tyndall, appearing to incline to the views of the latter writers. He does not, however, allude to electrical action in enumerating the causes of rain. Yet it seems to me there is no reason to believe that the aggregation or dissociation of clouds and the condensation of their particles is greatly due to the influence of this force. That the movements of cloud and mist are accompanied by strong electrical action has been shown by the experiments of Mr. Crosse, of Bromfield, and Mr. Ronalds;† and it is but reasonable to think that this action may have great influence on contiguous vapour, though unaccompanied by a disruptive discharge, or any luminous appearance. My observations induce me to think that electricity is also indirectly the cause of those peculiarities of refraction which depend upon the molecular condition of the vapour media through which the light passes, viz.-Halos, Parhelia, Paraselenæ, &c.; and I may here remark that these phenomena appear to have been unusually abundant during the past year, which has also afforded such exceptional displays of aurora, &c.

On the 21st September, a halo, of large diameter, say 60°, corresponded in position with the cirrhus clouds which formed the refracting medium. This halo followed the irregularities of the cloud to a considerable extent. Its disappearance was almost instantaneous, being caused apparently by the approach of a large mass of cumulus in the lower region of the sky. Almost as soon as the latter touched the lower part of the circle, the halo vanished. The irregularities in the circle of light at one time took the form of a series of separate arcs, which bent inwards, and appeared to be composed of half-dissolved cirrhus. These irregularities of form were also very conspicuous in a remarkable halo which was seen on Friday evening, December 19th. This assumed a spheroidal form, and was intersected by streaks of cirrhus, which changed their form rapidly, and showed a prismatic refraction like that of the halo itself. The vanishing of the first-mentioned halo was perhaps caused by an alteration in the constitution of its crystals or vesicles resulting from the electric action of the cloud below.

The next appearance I have to describe was of a singularly beautiful form and perfect definition. It appeared imbedded in a mass of homogeneous vapour, and consisted of two distinct rings, the inner one of a deep cobalt blue. This ring was distant from

* Intellectual Observer,' December, 1867.
† Vide Sir S. Harris's Electricity.'

the moon's disc about three diameters. Its outline was clearly defined, especially towards the inner part of the circle, and the colour was exquisite in tone. Farther from the moon, by about two apparent diameters, there was another ring, less defined and wider than the first, and of a beautiful crimson colour. Altogether this was the most beautiful appearance of the kind that I ever witnessed. It occurred about 11 P.M. on the evening following that on which the first-described halo appeared. All three were followed by drenching rain, lasting about a week in the first case. A gale came shortly after the second (December 19th). The cirrhus clouds which almost filled the sky resembled in form an appearance of aurora on this occasion, and had a peculiar motion, vanishing and reappearing in fresh forms, though there was no wind at the time.