History of the school board
It is not forbidden to write and draw on the walls of houses in ancient Rome. And the residents willingly did it. And since there were enough literate people, there were so many inscriptions that one witty citizen even scribbled such verses:
I'm surprised at you, wall, how could you not collapse, And you continue to carry so many crappy inscriptions!
Who taught the Romans to read and write? Strange as it may seem at first glance - slaves. Ancient Rome was famous for its rich culture, and its creators in the first place were not noble and rich slaveholders, but people who occupied a much more modest position. Prose writers, poets, philosophers, scientists, lawyers, doctors, artists, sculptors, architects, builders, artisans, in the vast majority of the world did not have any relation to the world. Among them there were many representatives of conquered peoples, freedmen and slaves. Almost all city slaves owned a literacy, moreover, teachers and doctors were mostly slaves.
School. Paris, 1815 School class. Fig. G. Doré.
And the first cool board was invented, as they say, by an unknown slave-teacher in Ancient Rome. What prompted him this invention? Maybe the wall is covered? Now no one will answer this question, but since that long time the powerful and yet unsurpassed means of transmitting information have been widely spread all over the world.
Board has changed little over the past hundreds of years. But it is necessary to improve it. Firstly, the size of the board is not always enough, at the same time, two students can answer the lesson, the strength of the three students. Secondly, children of small stature, no matter how long, can not reach the top edge. Thirdly, much time is spent on erasing what was written. Fourthly, even the most accurate ones leave the place most often at the board with soiled chalk hands and clothes. In short, the fact that the board should be improved, no doubt. But how?
A desk with a board. Late XIX - early XX century.
In some Japanese schools, the traditional black chalkboard was replaced with a white plastic board. They write on it with a pen with a thick brush, impregnated with easily erasable ink of six colors.
- You can make a board in the form of a loop wrapped in a ring that would be scrolled by hand or using a small electric motor. The upper drum is drive, and the lower one is immersed in a bath of water, where a special device ishes the chalk. Another option - the board is made in the form of a book. Due to this, its area is significantly increased.
And what if we compose a board from moving sections? So did the pupils of one of the schools in the Kursk region under the guidance of their mathematics teacher. You can answer at least half a class without interfering with each other, and in the course of the lesson you do not have to erase anything: its useful area is 17 square meters. This is three times more than a regular board. A student can turn his section from any angle, raise it, lower it, - in a word, adjust it to himself. Probably, for school such board is most convenient, because it is simple and does not require special maintenance.
But boards are needed not only in classrooms, in large halls, too - for lectures, conferences, seminars. For such cases, more complex devices are used. For example, instead of a wooden or plastic surface, a lighted glass panel is used, behind which there are a lot of small magnets in the niches. On the glass chalk can not write, but you can use an electromagnet. It is worth touching them to the panel, small magnets will pop out of their niches and stick to the back. If you touch quickly and immediately withdraw your hand, you get a point, and if you start writing, the magnets will exactly repeat your movements. Get the word, the drawing, the formula. For "erasures" images include another electromagnet, and all the magnets are hiding back into the niches.
In large auditoriums, when speaking, screens with an image projected on them are increasingly used. For such screens and the pointer should be special. It is light, and as a light source it uses a portable laser with battery power. A pointer highlights a bright red spot in the right place of the screen, which is clearly visible even in daylight.
Take note of
Look closely at the board in your class - it is possible that you will have interesting ideas. For example, make a board for music lessons. What will it be like?
Perhaps, "singing".As soon as the tip of the special pointer touches the drawn note, it begins to sound. Recorded on the blackboard with a pointer can be lost.