Simple practice of children's manual compasses

Preparation tools/materials: embroidery needle, water, bowl or cup, magnet, pen.

Step 1: Prepare the materials and tools needed to make a simple compass. See the figure below:

Step 2, rub the magnet back and forth on the embroidery needle several times. See the figure below:

Step 3: After rubbing, insert the needle into the cut paper. See the figure below:

Step 4: Write down the north-south direction on the paper. See the figure below:

Step five, put the paper into a bowl filled with water, and the compass is made here. See the figure below:

Second, the introduction of the compass:

Compass, called Sina in ancient times, is mainly composed of magnetic needles installed on the shaft. Under the action of natural geomagnetic field, the magnetic needle can rotate freely and keep in the tangential direction of magnetic meridian. The south pole of the magnetic needle points to the geographical south pole (magnetic north pole), and the direction can be distinguished by using this property.

It is often used in navigation, geodesy, tourism and military affairs. The invention of the compass with physical direction indication has three parts, namely Sina, compass and magnetic needle, all of which belong to the invention of China. According to ancient mine records, it first appeared in the Cishan area during the Warring States Period.

Compass is the result of China ancient working people's understanding of magnet magnetism in long-term practice. As one of four great inventions of ancient china, its invention has played an inestimable role in the development of human science, technology and civilization. In ancient China, the compass was first used for rituals, etiquette, military affairs and divination, and to determine the orientation when looking at Feng Shui.