Of course the construction may be varied very much, and it may be more or less expensive, according to the wishes of the teacher. In the first apparatus of this kind which I used, the plate was simply a card of pasteboard, from which the machine took its name. This was cut out with a penknife, and after being covered with marble paper, a strip of white paper was pasted along the middle, with the inscription upon it. The wire c c and a similar one at the top of the plate, were passed through a perforation in the pasteboard, and then passed into the board. Instead of a pulley, the cord, which was a piece of twine, was passed through a little staple made of wire and driven into the board. The whole was made in one or two recesses in school, with such tools and materials as I could then command. The bell was a common table bell, with a wire passing through the handle. The whole was attached to such a piece of pine board as I could get on the occasion. This coarse contrivance was, for more than a year, the grand regulator of all the movements of the school.

      I afterwards had one made in a better manner. The plate is of tin, gilded, the border and the letters of the inscription being black. A parlor bell rope passes over a brass pulley, and then runs downward in a groove made in the mahogany board to which the card is attached.

      A little reflection will, however, show the teacher that the form and construction of the apparatus for marking the times of study and of rest, may be greatly varied. The chief point is simply to secure the principle, of whispering at definite and limited times, and at those alone. If such an arrangement is adopted, and carried faithfully into effect, it will be found to relieve the teacher of more than half of the confusion and perplexity, which would otherwise be his hourly lot. I have detailed thus particularly the method to be pursued in carrying this principle into effect, because I am convinced of its importance, and the incalculable assistance which such an arrangement will afford to the teacher in all his plans. Of course, I would not be understood to recommend its adoption, in those cases, where, teachers, from their own experience, have devised and adopted other plans, which accomplish as effectually the same purpose. All that I mean, is to insist upon the absolute necessity of some plan, to remove this very common source of interruption and confusion, and I recommend this mode where a better is not known.

      2. The second of the sources of interruption, as I have enumerated them, is mending pens. This business ought, if possible, to have a specific time assigned to it. Scholars are in general far too particular in regard to their pens. The teacher ought to explain to them that, in the transaction of the ordinary business of life, they cannot, always, have exactly such a pen as they would like. They must learn to write with various kinds of pens, and when furnished with one that the teacher himself would consider suitable to write a letter to a friend with, he must be content. They should understand that the form of the letters is what is important in learning to write, not the smoothness and clearness of the hair lines; and that though writing looks better, when executed with a perfect pen, a person may learn to write, nearly as well with one, which is not absolutely perfect. So certain is this, though often overlooked, that a person would perhaps learn faster with chalk upon a black board, than with the best goose-quill ever sharpened.

      I do not make these remarks to show that it is of no consequence, whether scholars have good or bad pens, but only that this subject deserves very much less of the time and attention of the teacher, than it usually receives. When the scholars are allowed, as they very generally are, to come, when they please, to present their pens, some four, five or six times in a day—breaking in upon any business—interrupting any classes—perplexing and embarrassing the teacher, however he may be employed,—there is a very serious obstruction to the progress of the scholars, which is by no means repaid by the improvement in this branch.

      There are several ways by which this evil may be remedied, or at least be very effectually curtailed. Some teachers take their pens with them, and mend them in the evening at home. For various reasons, this cannot always be practised. There may, however, be a time set apart in the school specially for this purpose. But the best plan is, for the teacher not to mend the pens himself.

      Let him choose from among the older and more intelligent of his scholars, four or five, whom he will teach. They will be very glad to learn, and to mend every day twenty-five or fifty pens each. Very little ingenuity will be necessary to devise some plan, by which the scholars may be apportioned among these, so that each shall supply a given number, and the teacher be relieved entirely.

      3. Answering questions about studies. A teacher who does not adopt some system in regard to this subject, will be always at the mercy of his scholars. One boy will want to know how to parse a word, another where the lesson is, another to have a sum explained, and a fourth will wish to show his work, to see if it is right. The teacher does not like to discourage such inquiries. Each one, as it comes up, seems necessary: each one too is answered in a moment; but the endless number, and the continual repetition of them consume his time and exhaust his patience.

      There is another view of the subject, which ought to be taken. Perhaps it would not be far from the truth, to estimate the average number of scholars in the schools in our country, at fifty. At any rate, this will be near enough for our present purpose. There are three hours in each session, making one hundred and eighty minutes, which, divided among fifty, give about three minutes and a half to each individual. If the reader has, in his own school, a greater or a less number, he can easily correct the above, so as to adapt it to his own case, and ascertain the portion, which may justly be appropriated to each pupil. It will probably vary from two to four minutes. Now a period of four minutes slips away very fast while a man is looking over perplexing problems, and if he exceeds that time at all, he is doing injustice to his other pupils. I do not mean that a man is to confine himself, rigidly, to the principle suggested by this calculation, of cautiously appropriating no more time to any one of his pupils, than such a calculation would assign to each; but simply that this is a point which should be kept in view, and have a very strong influence in deciding how far it is right to devote attention, exclusively, to individuals. It seems to me that it shows very clearly, that one ought to teach his pupils, as much as possible, in masses, and as little as possible, by private attention to individual cases.

      The following directions will help the teacher to carry these principles into effect. When you assign a lesson, glance over it yourself, and consider what difficulties are likely to arise. You know the progress which your pupils have made, and can easily anticipate their difficulties. Tell them all together, in the class,