The thick cloth was lifted, and below it was a wooden platform of length and width, surrounded by wooden planks, and in the middle was a mountain peak plain made of mud, sand, wood chips and other things! There are also intricately made castles, tents and other objects scattered on it, and what is even more surprising is that there is still water flowing through the valley!

"This is Chang'an! This is Weishui! Wei Qing beside Liu Che blurted out, pointing to the city and river on the edge of the wooden platform and said, then his finger moved to the west, "So these are the Hexi to the Western Regions?" ”

"Yes! This is a sand table from Hexi to the Western Regions made by us based on what we saw along the way and the oral accounts of Tangyi's father, Fumi camel, Huvishka and others! Li You nodded in response, this is what he asked Liu Che to come to build under the master craftsman, a sand table model that is extremely shocking for the current era.

The sand table first appeared in the Qin Dynasty, when Qin deployed to destroy the Six Kingdoms, Qin Shi Huang personally piled up and studied the geographical situation of each country, and with the assistance of Li Si, sent the general Wang Jian to carry out a unified war. Later, when Qin Shi Huang was building the mausoleum, he built a large topographic model in his own mausoleum. The model not only has mountains, hills, cities, etc., but also simulates rivers and seas with mercury, and uses mechanical devices to make mercury flow and circulate; It's a pity that this most luxurious sand table in history has not been presented to everyone until the later generations where Li You is located!

After that, the sand table was not used in the military, until the Guangwu Emperor Liu Xiu conquered Tianshui, Wudu and other places were strong and noisy, the general Ma Yuan "gathered rice for the valley, pointed to the situation", so that the Guangwu Emperor suddenly had the feeling of "captive in my eyes", which can be said to be the first application of the sand table in the history of human military affairs!

And in this world, Li You has advanced this time by two hundred years! Let Liu Xiu's ancestor Liu Che, Emperor Wu of the Han Dynasty, also have a chance to see the style of this military weapon.

"Your Majesty, please look!" Li You pointed to the mountains and rivers and ravines on the sand table, "This is Chang'an City, and the minister set off from here to reach the border pass last year, and the exit of the pass went west along the Qilian Mountain, crossed the river to reach the territory of King Hutu, and then crossed the territory of King Kun to reach the Loulan Kingdom in the Western Regions!" It is the country where the prince of Fumi camel is located, and then continue to the west, through the Yanqi country, the Qiuzi country, the Gumo country, and the Shule country to reach the territory of the Dayue clan, and then go south through the Shache country, the Khotanese country, the Jingjue country, and the end of the country back to Loulan! Follow the original westbound road to the east and return to the territory of Dahan and arrive in Chang'an! ”

Liu Che's gaze followed the movement of Li You's fingers and swept across the mountains, rivers, deserts and grasslands he passed, and his mood could not be calmed for a long time, until he saw this sand table, he had an intuitive understanding of the land of the Han Dynasty and the territory of the Xiongnu under his command, and after a long time, he exhaled a breath and praised sincerely, "Zhang Aiqing has worked too hard all the way!" ”

When he first heard the oral description, he only had a vague understanding of the difficulties of this trip, but it was not until he saw this sand table that his understanding gradually became clear; On the sand table, Chang'an City only occupies such a large position, so how long and difficult is the road traveled by the Han mission!

"Zhang Aiqing, why is this mountaintop white? It's like it's snowing in winter? Liu Che soon discovered the strangeness on the sand table, he had also been to Zhongnan Mountain near Chang'an and other places, but unless it was winter, these mountains were all green, look at the sand table near Chang'an The mountains are like this, why is the mountainside below the green mountainside, but it turns white at the top of the mountain? What is the reason?

Well, it seems a little early to talk to him about the relationship between altitude and temperature at this time, right? Do you want me to start with junior high school physics? After struggling for a moment, Li You still decided to ignore the real reason, "Your Majesty, this mountain is a big mountain that we climbed before crossing the river and entering the territory of King Hutu, and the snow on the top of this big mountain will not melt all year round!" Therefore, the minister painted the top of his mountain white! If our army wants to march west from here, we must prepare cotton clothes and other things to protect against the cold! ”

"The world is so big!" Hearing that there is still snow that does not melt in the middle of summer, Liu Che said with emotion, and then his finger pointed to the Taklamakan Desert between the Tianshan Mountains and the Kunlun Mountains, "Why is there all sand here?" Why didn't Zhang Aiqing pass through this directly when he returned from the Western Regions? But went south and went around in such a big circle? ”

"Your Majesty! Here is a sea of sand that stretches for thousands of miles, and there is no water, no grass and trees in the sea of sand, only a long stretch of yellow sand! Once a person breaks into it, he will die of thirst and hunger, and he will not be able to leave! Li You replied truthfully.

"I see!" Liu Che, who grew up in the Guanzhong Plain, couldn't imagine what the desert was like, he hid this matter in his heart and continued to ask, "This is the territory of King Hutu and King Kunxie?" ”

"Yes! The Xiongnu Da Dan Yu led all the departments, and there were twenty-four chiefs under him who led the soldiers and horses from all over the country, and the King of Xiu Tu and the King of Kun Evil were one of the twenty-four chiefs! Each of them has a population of tens of thousands, more than 10,000 soldiers and horses! It's just that right now, they are being hunted by the military minister Shan Yu who was sent to the Western Regions to assist the Wusun Kingdom, and it is difficult to return for a while! Now that the area around Hexi is empty, it is the time for our army to march westward! Speaking of this, Li You raised his voice, "This western expedition will definitely be able to defeat the Huns, sweep away the shame of Baideng in the past, and raise the prestige of my Han army!" ”

"With this thing, it is in my eyes!" Liu Che excitedly grasped the wooden board on the edge of the sand table with both hands, and the force was so great that his knuckles began to turn white, "Immediately summon Dou Ying and Tian Wei here!" I want them to see this treasure of Zhang Aiqing! ”

Compared with Prime Minister Xu Chang, Taiwei Zhuang Qingzhai and others who ascended to the throne because of Empress Dowager Dou, Liu Che trusted old courtiers like Dou Ying and Tian Wei more, and when he thought clearly about the usefulness of the sand table, he immediately thought of them.

"Where is the Xiongnu royal court?" The eunuch who delivered the decree left in a hurry, and Liu Che looked at the sand table again.

Li You's fingers followed Chang'an northward to the vicinity of Ulaanbaatar, the capital of later Mongolia, "Your Majesty, the Xiongnu royal court is here!" It is three or four thousand miles away from Chang'an! The straight-line distance from Xi'an to Ulaanbaatar is 1531 kilometers, Li You pointed to the large blank space between Chang'an and the Xiongnu royal court and said regretfully, "It's a pity that Tangyi's father has left the Xiongnu for more than ten years, and the memory is inevitably blurred, so this part is not very clear!" In the future, the only way to do this is to let the messengers and merchants probe more and then slowly refine the filling! ”

"Nowadays, there are only mountains and rivers from Hexi to the Western Regions and the Han Dynasty on the sand table, which is still accurate! Other areas need to be constantly replenished! Li You reminded that he didn't want Liu Che to start planning the Battle of Mobei based on this sand table.

"Sand table? But what does it mean to gather sand into a plate? That's a good name! Liu Che nodded in praise.