First, the cellar temperature is not much higher than the ground temperature. We know that for every 100 meters of elevation gain on the ground, the temperature difference is about 0.6 degrees Celsius. The cellar is less affected by the wind, plus closer to the center of the earth, so the temperature is higher than the ground, but not much higher, the temperature difference is about 5-10 degrees, the reason why I feel warm inside, a big reason is that the cellar is not subject to cold wind.
Second, the cellar space is generally very small, so as to ensure that the temperature inside the space is higher than outside. This leads to the cellar can only accommodate a few people, such a small space, to stay a long time breathing problems, is not suitable for people to live in the cold. If you expand the volume of the cellar, the temperature inside the cellar will be reduced, and can not play the role of insulation.
Thirdly, it is accurate to say that the ancients did not die because of freezing. Although the temperature in winter was very low in ancient times, the ancients had many ways to spend the winter. The ancients would hunt all kinds of animal furs to make clothes, and the warmth of such furs was unquestionable. There is also the production of various kinds of fireplace. The average family can be equipped with such tools. Those who couldn't be equipped with these tools were mostly very poor families, so poor that eating was a problem, and as they didn't have enough to eat in winter, their resistance was naturally poor, so they would freeze to death outdoors. Therefore, cellars are used by people for storage and are not suitable for people to live in to avoid the cold.
And the poor people referred to by the owner here should be beggars, because in ancient times those who could be called poor generally had their own houses and even a little bit of thin land. It is only that their life is more difficult, and not to the point of sleeping on the streets.?
And the beggar is different, they have no house and no land, there is just a ragged clothes and a broken bowl, the conditions of a little better may also have a dog fighting stick. Usually they eat? Hundreds of rice? and sleep on the streets at night. Warmer weather is good to live wherever you can, to the cold winter they can be unlucky, the cold wind blowing on the thin clothes, freezing them shivering, can not carry over the beggars may freeze to death on the street.
But if so why don't they dig a cellar? Digging a cellar, like building a house, requires sufficient productivity, production tools, production materials, production time? How can they produce this big project when they are old, weak, sick and disabled with no muscles and no feet? If you can complete this project that will not be beggars.
And this is a bit like why not eat meat loaf? In our country suitable for digging cellar place is few and far between. Primitive man may cave that is also the use of natural caves, the population of a large number of cases of reproduction to find caves to live in the possibility of very small. China is suitable for digging a cellar for long-term living place is also estimated to be the Loess Plateau, Northeast China North China Plain digging a cellar, it is easy to live not long on the collapse, because the soil climate is not the same. When I was a kid, my family's sweet potato cellar was cleaned and re-hooped every year before storage. Some sweet potato cellar collapsed in a year. The south is humid and rainy more unsuitable for cellar.?
The wisdom of the ancient working people is not bad, on the contrary, in that era most of them rely on the sale of energy and skills to solve the problem, they are more powerful than us do not know how much.