In spite of these objections my proposal is as follows:(1) To make use of the College Entrance Examinations as Standards in Science Teaching.

(2) To economize time by concentration of effort on fundamentals so that two to three months of each year may be spent in a many-sided review.

(3) To require answers to questions on the fundamentals repeatedly written in clear, concise, accurate English.

(4) To make the introductory lessons, in physics especially, very easy. To cultivate power by gradually increasing their difficulty. This amounts to a sliding standard, low but thorough at the beginning of the year and severe and high at the endthe ability to give satisfactory answers to such questions as are asked at the college examinations.

A COURSE IN ELECTRICAL ENGINEERING FOR TEACHERS OF PHYSICS IN SECONDARY SCHOOLS.

BY GEORGE A. COWEN,

West Roxbury High School, Boston.

There has been in progress during the current year at the Massachusetts Institute of Technology a course in Electrical Engineering and Testing provided by the trustees of the Lowell Institute in connection with its Teachers' School of Science.

The desire and plans for the course originated in the Eastern Association of Physics Teachers. It was designed to meet the needs of the members of that association although it was thrown. open to all other teachers qualified to do the work. Until this time there had been almost no opportunity for teachers in secondary schools to do any advanced work in physics under expert supervision. Courses were open with the regular students at some of the near by educational institutions, but the lectures came on other days than Saturday so that the work be undertaken only by a favored few living within a short radius.

There were fifteen lectures, five upon the construction, use and calibration of electrical measuring instruments and ten devoted to a discussion of dynamo electric machnery. The lectures were followed by fifteen laboratory exercises, five in the standardizing and ten in the engineering department. The laboratory was open for three hours on each Saturday afternoon.

Five out of the following list were done by each in the standardizing laboratory: Wheatstone bridge, conductivity, Poggendorf method, voltmeter calibration, ammeter calibration, potentio meter, direct current wattmeter, insulation resistance, capacity, cable test.

In the engineering department the list of exercises was as follows:

Shunt motor, its efficiency and the ordinary motor curves; series motor, efficiency and curves; differential motor; Stray power method; characteristics of a series generator; shunt and compound motor; methods of speed variations of a shunt motor; shunt generators in parallel; incandescent light photometry; dy

namotor.

Prof. H. E. Clifford, the head of the engineering department, was in charge of the course and delivered two of the lectures. The remainder of the work was done by assistant Professors T. A. Laws, H. W. Smith, and R. R. Lawrence.

Forty-nine registered in the course. Of these seven attended the lectures only. The average attendance at the lectures was about forty. In the laboratory section there were six who dropped out before the work was completed. Seven of those completing the work were young women. A fair idea of the interest taken in the course may be obtained by noticing the distances many of the teachers traveled in order to be present. Seventeen lived in Boston; nineteen came from a distance of about ten miles; six came twenty-five miles, and seven came forty miles.

The course was absolutely free, the expense having been provided by the trustees of the Lowell Institute. Had it not been free the cost per member would have been not far from $25.00. Teachers in this part of the country are not overpaid, so it is possible that a fee of $25.00 even would have prevented those living at a distance from taking the course.

Forty-four have already signified their desire to supplement this work by a course on alternating currents next year. The demand shows the success of the present undertaking.

This bringing together weekly the most progressive teachers of Physics in Eastern Massachusetts must of necessity unify, enrich, and raise the standard of the work in this department of science.

It seems to be a plan capable of being followed in any center having a college or technical school.

TWO INTERESTING PHYSICS EXPERIMENTS.

BY FRANK M. GREENLAW,

Rogers High School, Newport, R. I.

The following experiment has been used by the writer for several years to make visible to classes the reduction of temperature of a gas through expansion, as well as the lowering of the boiling point under diminished pressure.

A flask partly full of water is closed with a two hole rubber stopper, through one opening a chemical thermometer is passed, through the other a short piece of bent tubing over which is slipped a short length of rubber tubing and a Mahr Pinchcock. The flask is heated to boiling and when the air has been displaced the flask is removed and the pinchcock closed. Now instead of cooling the flask by dropping water on it, as is usually done, it is connected to a second flask from which the air has been exhausted as thoroughly as possible, and communication between the two is established by releasing the pinchcock. The reduction of pressure not only produces rapid ebullition in the flask containing water but cools the expanding water vapor to such an extent that the exhausted flask becomes filled with a dense fog. The writer has also prepared magnetic field slides, for lantern use as follows:

An ordinary lantern slide cover glass is coated with a thin film of paraffine and the field mapped with iron filings upon this film in the usual way. The plate is then passed through a bunsen flame to soften the paraffine and "fix" the filings-and in a moment or two the plate has cooled sufficiently to use in the lantern. If bound with a fairly thick mat a very permanent and effective slide results.

The aggregate value of all the products obtained from the distillation of coal in gas works and retort ovens in 1905 was $56,684,972, as against $51,157,736 in 1904 and $47,830,600 in 1903.

The value of the natural gas produced in 1905 was $41,562,855, as compared with $38,496,760 in 1904, with $35,807.860 in 1903, with $30,867,863 in 1902, with $27,066,077 in 1901, and with $23,698,674 in 1900 -a gain of about 8 per cent in 1905 over 1904.

THE POINT OF VIEW IN CHEMISTRY.
BY ALEXANDER SMITH,

University of Chicago.

In an important sense it is not the particular selection of topics. that determines the real value of a course in chemistry, but the point of view of the teacher who presents them. Yet, although all-pervading and all-important, this point of view is of all things the most difficult to define or describe. It may be felt in every word uttered in the class room, but is itself almost impossible of capture and of crystallization in words. We may seize some of its characteristics best, perhaps, by dipping into the teacher's version of the science here and there, taking a few samples and considering the mode of their treatment. The choice of samples may be determined by noting the points on which authors differ and the points in regard to which one's own views have changed; consideration of the points where there is a diversity of views and where changes in view have occurred should give some indication of the deeper seated, fundamental ideas whose influence determines the choice or suggests the change.

Let us take, first, the question, What principle is most fundamental in all chemical work; what fact is the basis of our performance and interpretation of every chemical experiment? Is it the atomic hypothesis? Many chemists used to think so, and some chemists still think so. In a recent text-book the most of the first chapter is devoted to a discussion of the minute subdivisions of matter and of the conceptions arising from a consideration of this subdivision. The treatment is logical, and satisfactory from the point of view that this is the fundamental idea at the basis of chemical thought and work. But, after all, does the chemist in point of fact carry on his work by considerations of this kind? Are there not facts about masses of material which are more continually in his thought? Would not a man who had encountered animal matter only at meal times in a Chinese restaurant have a rather distorted idea of the nature and structure of fish, flesh, and fowl, and does not the reduction of the carcass to chop suey obliterate or obscure some facts of large significance in Zoology? And does not, in the same way, a premature consideration of an imaginary process of utter disintegration withdraw the attention from the common aspects of chemical behavior as it really appears? The answer, of course, depends on one's point of view.

What, then should demand our attention, before the pulverization begins? Is it the principle of definite proportions? Does not this presuppose the conception of compounds and is not therefore the idea of elements and compounds more fundamental? Is this then itself the fact of which we are in search, the fact which is at the basis of all chemical work? But how do we recognize a compound? Is it not by obtaining from the compound two or more substances, with properties which distinguish them from one another and from the parent substance? Is not the basis, then, of chemical work the fact that each substance has its own set of specific, physical properties by means of which the substance is recognized and by use of which the substance is separated from other substances when necessary? In the point of view with which at present I sympathize, it is. And this particular view must have a large influence on the way in which emphasis is placed in doing and discussing chemical experiments. It at once puts in the foreground, as the object of every experiment, the observation of physical phenomena and the discussion of the observations in terms of physical realities.

Let us now turn to another subject, the treatment of which may give indications of the point of view. The atomic hypothesis has already been mentioned. At what stage may this hypothesis most usefully be introduced? The answer is found by asking, what fact in chemistry was it primarily devised to explain? Was it not the fact that the proportions by weight in which a given element enters into all sorts of combinations may always be expressed by a fixed number, or by whole multiples of this fixed number? The sypothesis comes in, then, when combining proportions by weight are discussed. In other words, the hypothesis is used in explaining the quantitative laws of chemical combination. May it be used at an earlier stage, for example, to explain the fact of chemical combination and the qualitative features associated with it? Does it clear up the mystery of the properties peculiar to cupric sulphide to say that a little piece of copper, "which has all the properties of a large quantity of the substance," when stuck to a little piece of sulphur, will give a little aggregate whose properties will be absolutely unrelated to those of the constituent atoms? Would not even a child see that the properties of a mass composed of the aggregates ought to be the average of those of two masses composed, respectively, of the pieces of copper and the pieces of sulphur? And if the