After a day's trek, Xu Xiake insisted on recording his findings no matter how tired he was or where he lived. His travels have more than 2.4 million words, but most of them are scattered. What was left was the famous Travels of Xu Xiake, which was compiled into a book by later generations. With more than 400,000 words, this book is a great "good book" integrating science and literature.
Xu Xiake's visit is not only to discover new things, but more importantly, to explore the mysteries of nature and discover its laws. For example, his river flow surveys in Jiangxi and Ningyang, Fujian are examples. Liling and Maling are the cradles of Jiangxi and Ningyang respectively. The heights of the two ridges are roughly equal, but the flow of the two streams into the sea is quite different. Jiangxi is long and Ningyang is short in the west. After investigation, Xu Xiake found that the current of Ningyang River is faster than that of Jiangxi. "The harder the journey, the more urgent the flow of people", that is, the shorter the distance, the more urgent the flow of people. This famous geographical conclusion was drawn by Xu Xiake through on-the-spot investigation. His investigation and study of mountains, water, geology and landforms has made achievements beyond those of his predecessors.
He explored the sources of many rivers, such as the left and right rivers, small rivers and banks in Guangxi, tributaries of Xiangjiang River, Yunnan River and Yangtze River, among which the Yangtze River is the deepest. The mighty Yangtze River flows through most of China, and its birthplace has always been a mystery. Gong Yu, a geography book in the Warring States Period, said that "Minjiang River is the source of rivers", which was used in later books. Xu Xiake expressed doubts about this. With the question of "Sanqin in the north, Wuling in the south, and Shimen Jinsha in the west", he found that Jinsha River originated at the southern foot of Kunlun Mountain and was more than 0/000 Li longer than Minjiang River, so he concluded that Jinsha River was the source of the upper reaches of the Yangtze River. Due to the limitation of the conditions at that time, Xu Xiake failed to find the real source of the Yangtze River. However, he took an extremely important step and found the source of the Yangtze River. No one found out for a long time after him. It was not until 1978 that China sent an expedition to confirm this.
Xu Xiake is also a pioneer in the scientific research of limestone landforms in the world. Limestone is widely distributed in southwest China. Xu Xiake made a detailed investigation in Hunan, Guangxi, Guizhou, Yunnan and other places, and described, recorded and studied the limestone landforms in various places in detail. He also inspected more than 100 limestone caves. In Jiuyi Mountain in southern Hunan, he heard that there was a flying Longyan, so he asked the local monk Mingzong to take a torch to investigate. Longfei Mountain is a huge cave with twists and turns. There is a hole in the cave, which is full of pits and water. It is difficult to walk. Xu Xiake doesn't care about these, but goes deep into them. He doesn't care if his shoes will run away. Mingzong advised him to go back several times, but he wouldn't listen. It was not until the torch was almost burned out that he reluctantly went back. He doesn't have any instruments, but only by visual inspection, but most of his investigations are very scientific. For example, the records of Seven-Star Rock 15 caves in Guilin are generally consistent with the results of field visits by geographical researchers today. More than a hundred years after Xu Xiake's death, Europeans began to investigate limestone landforms. Xu Xiake is the earliest limestone geomorphologist in the world.
Xu Xiake has made many contributions to geographical science. In addition, he also studied geothermal phenomena such as volcanoes and hot springs, and described and studied natural phenomena such as climate change and plant changes due to different topography. In addition, he vividly described and recorded the situation of agriculture, handicrafts and transportation, the evolution of scenic spots and historical sites and the customs of ethnic minorities. His books are wonderful and of high literary value, which can be said to be beautiful prose.
Xu Xiake's last trip was in 1636, when he was 5 1 year old. This time, I mainly went to the southwest of China, arrived at Tengyue on the border between China and Myanmar, and 1640 went back to my hometown. He fell ill soon after he got home. During his illness, he also looked at the rock samples he collected. Before he died, he still had two stones in his hand.
Xu Xiake's spirit of loving the motherland, science and daring to climb the peak of scientific career is worth learning forever.