fact that the pupil's choice is more real, and his interest is therefore greater. This year, I expect to use both plans. The class has completed a set of projects in connection with chlorine, such as gas masks and gas warfare, bleaching powder, commercial preparation of chlorine, the preparation of other halogen elements, and another set dealing with sodium compounds. This has given them a chance to become more familiar with the use of equations, and to acquire more confidence in their ability to work independently. Their next assignment will be from the longer unrelated list of projects.

Most of the recitation time is used for the pupils' reports. The rest of the class takes notes on the reports as given, and answers a list of questions which the pupil conducting the class has made to cover the subject as he has presented it. From time to time, however, the teacher should take charge of a recitation for the purpose of relating the individual projects, and of bringing out the principles which have been illustrated by the work. For example, after the projects dealing with chlorine, bromine, and iodine, a recitation reviewing the chief characteristics of these elements and introducing the idea of the periodic arrangement is valuable in unifying the individual projects. The ideas of ionization and reversibility can be brought out by a recitation reviewing the preparation of the different sodium compounds. The theory of ionization has been used and explained by the pupil who studied the electrolytic preparation of chlorine. It should be pointed out to the pupils who are studying the Solvay Process, the reaction of baking powder, the making of caustic soda, that they are working with acids, bases and salts in solution, therefore with ions. With the completion of the calcium work, a comparison of formulae, as Na CO, CaCO3, NaOH, Ca(OH)2, introduces the idea of valence. This can be connected with the number of charges that an ion carries. The class can then be asked to learn the valence of the common elements and groups, and some drill can be given in writing formulae and balancing equations.

The grouping of projects, the review recitation, and the recitation presenting general principles growing out of the projects, are then ways in which we may unify the work, and in this manner make the reports of individuals valuable to the whole class. The other question that we need to consider is the amount and kind of guidance that should be given the pupil in his own project, in order that he may not waste time in ineffec

tual work, and that he may develop initiative in solving his own problems in his own way.

In the small class, where the teacher can know what project each pupil is engaged in, and just how far he has progressed in it, the pupil can be left largely to his own initiative, with suggestions given by the teacher as the need arises. But in larger classes some guidance is necessary, as the teacher can not be everywhere, and answer every one's question at the psychological moment. A set of cards can be prepared for each project, giving a list of references and experiments. With this card as a starting point, the pupil can go ahead, but he should understand that the references given are simply a starting point, from which he is to develop his project according to his own ideas, adding other references and experiments as he works.

At present I am trying another plan, that of giving a set of leading questions, which indicate in general outline what the pupil needs to find out but leaving him to find information for himself wherever he can. The following set of questions is the one used on the project "nitric acid and explosives."

What is the general method of preparing an acid? Recall the method by which you prepared hydrogen chloride.

How could nitric acid be prepared in a similar way?

What property of hydrogen chloride enabled you to separate it from the sulphuric acid used?

Would it be possible to separate nitric and sulphuric acids in the same way?

What salt is used in preparing nitric acid? Is the quantity of this salt unlimited?

Prepare some nitric acid, and study its properties.

Make some gun cotton.

What is the theory of explosives?

Why is gun cotton a better explosive than Chinese gunpowder?

Why is sulphuric acid used in making guncotton?

What is dynamite? T. N. T.? What is celluloid? How does it re

semble guncotton?

Could nitric acid be made starting with nitrogen?

What are the difficulties?

What is the Haber process?

Why did the government spend millions of dollars on the Mussels Shoals nitrate plant during the war?

Is this too much guidance? It may be. If the outline suggested in the questions is too slavishly followed, it may not leave any room for initiative on the part of the pupil. As the class which is using these outlines has not yet reported on the projects studied in this way, I am not prepared to say whether the outline is a help or hindrance. In working with large classes, we must be on our guard not to over-organize the method, and so lose its characteristic advantages. Before a pupil reports, it is well to have a short conference with him, in which he may outline the

way in which he is planning to present his material to the class. This gives the teacher a chance to suggest any changes in the order of presentation, which may make the work clearer to the other students, to correct any wrong ideas, and point out any gaps in the pupil's information. I think that an outline like the above on nitric acid, might serve better as a conclusion than as a starting point. After a student has worked out his project according to his own plan, such a list of questions would allow him to test his knowledge before he makes his final report but would not limit his project for him at the start. There is still much experimental work to be done before we find out how to give the right amount of guidance in the right way.

As to the results of this method, we have felt that there was more real interest and more genuine activity on the part of the class, when we were allowing them to work on their own projects. At the end of the year, I asked two classes to indicate their preference. I know that a class vote may be somewhat influenced by what the class thinks is the teacher's preference, so I tried to make it clear that I wanted their real opinion, that I did not care how the vote went. The vote stood 32-12 in favor of the project method. Pupils who have finished the course come back and tell us how much they enjoyed the work, and how well they remember and are able to apply the information gained in working on their projects. But you will say interest is not an accurate measure of accomplishment, and while the knowledge of the projects worked out may remain, do the pupils get enough out of the projects reported to them by other members of the class to have as wide range of information, as they would obtain from doing each experiment for themselves? Mr. S. R. Power's tests have given us some accurate information on this point. I

have the results of the three chemistry tests and the intelligence test for all of the Chemistry IIs (second semester classes) in the department last June.

Test 1 covered mainly the writing of formulae, the naming of formulae, the completion and balancing of equations, and the writing of equations for familiar laboratory reactions. On this test two project-taught classes averaged from 3-7 points above the non-project classes, and a third project class averaged slightly below. The average of the project-taught classes was 45.28 and that of the non-project classes was 40.82 on Test 1. Test two was the range of information test. Here the projecttaught classes averaged 30.5, the non-project classes 28.9. I consider this a more important test, as the ability to manipulate equations depends on the emphasis and practice given directly, and is not a by-product of any method. Range of information as accurate and as extensive as possible is a more important aim of high school chemistry, and the tests show that the project classes excelled somewhat in this. Test 3 was designed to test the pupil's ability to solve a problem question involving the use of facts which he has learned in other connections. Perhaps this is the most important aim of any school subject, to give the pupil power in solving problems, using the subject matter of chemistry or any other subject to develop this ability. Certainly this is the hardest aim to accomplish in teaching. On test three the project classes averaged 17.16 as against 16.52 for the others. The intelligence average for the project classes was 74.8; the non-project classes had an average of 81.7. The test results with the seven classes indicate that the accomplishment of the project classes, measured by standard tests, was slightly better than that of the non-project classes, although the intelligence rating of the latter was almost 7 points higher.

On test 2, we were able to check the performance of different sections on questions which had been reported to them by pupils, as the project lists had not been the same in each section. On test 2 question 14 deals with Plaster of Paris. In the section which had had a report on Plaster of Paris, 15 answered the question correctly; in the other section which had not had that project there were 9 correct answers. The question on cellulose was answered correctly by 16 in the section that had had it as a project, and only by five in the other section. The question on blue prints received 15 correct answers from the section that had had a report on photography, and by five in the other class.

These results indicate that the pupils in a project class do get and retain information on the material which is reported to them by other pupils.

From the point of view of the teacher the project method has its advantages. It is more flexible, more easily experimented with so there is less danger of getting into a rut. One may hesitate to try out new material on a whole class, but it is very easy to add new projects to the list, to be retained or dropped as experience indicates. In this way the teacher is not constantly going over the same material, but can add new material that is pertinent to different locations or suggested by current events. In the formally organized course the pupils have not the interest. that they have in these tasks of their own choosing. This interest, and the responsibility which they have for giving the result of their investigation to the rest of the class, furnish real motives, and result in purposeful activity that is very gratifying to the teacher. I am conducting my fourth class by the project method, and while I feel that there are still problems to be solved, and difficulties to be smoothed out, my experience has convinced me that the inherent advantages of the method are so great, that it will pay any teacher to incorporate some project work into his teaching,

SHOWING THE EARTH'S MOVEMENT.

It is commonly supposed that it is not possible to demonstrate the movement of the earth without elaborate apparatus. This is very far from being the case as a simple device will indicate the earth's motion.

In the first place select a room that is fairly free from vibration. Then obtain a good-sized bowl or tub a foot or more in diameter and rather deep and nearly fill it with water. Place this on the floor of the room in such a position that it need not be disturbed for some hours. Get some finely powdered resin and sprinkle a coating of this on the surface of the water. Any fine substance that would float and not be dissolved. for some hours would do as well. Next secure a little coal dust and sprinkle some on the top of the resin doing this in a straight line from the center to the circumference. Carry this line up over the rim of the bowl, and make it broad enough to be clearly seen-say about an inch in width. The bowl may now be left for several hours, at the end of which time it will be noticed that an interesting thing has happened. It will be seen that the line on the surface of the water has changed its position and that it no longer meets that which runs up over the rim of the bowl. As a matter of fact the black line on the surface of the water has swept around from east to west.

What has happened is this: The water in the bowl has stood still throughout the time which it has been left while the vessel itself has been carried around by the motion of the earth from west to east. Another way of putting it is that the earth has swung around through a considerable arc from west to east, leaving the water quite stationary.-[By S. Leonard Bastin, in Scientific American.