Yuan Tiangang, also known as "Yuan Tiangang", was a native of Chengdu, Sichuan, a metaphysician and astronomer. In the last years of the Sui Dynasty, Yuan Tiangang built a house in front of Panlong Mountain in Langzhou.
Li Chunfeng, a native of Qishan County, Shaanxi Province, like Yuan Tiangang, was proficient in astronomy, almanac, yin and yang, and Taoism. Li Chunfeng was also the first in the world to grade the wind, and his famous book "Yi Wei Zhan" is the earliest monograph in the history of world meteorology.
The most widely circulated story of the two is that they collaborated to complete "Push Back Map". Interacting with Yuan Tiangang, Li Chunfeng respected him with the etiquette of treating his teacher. Because of a cow, Li Chunfeng admired Yuan Tiangang.
One day, the two of them took a green outing and saw a line of cattle walking on the grass. Yuan Tiangang then said: "According to the traces, this is a cow, and she is pregnant, and the cow's left eye must be blind, and it can give birth to a small bull smoothly." ”
I'm a good looker, and when I see the footprints of a cow, I can tell if it's male or female? Still say this cow is pregnant? Or is it said that it must be blind in the left eye? Also said it can give birth to a baby bull? A simple sign that he Yuan Tiangang can identify four unknown events? Note that this is "OK", not "speculative".
Bull's Eye Blind? Are you blind? Does this ignite and blow up? I Li Chunfeng is not an idle person, why can't I see anything? No, I have to be careful.
So Li Chunfeng secretly followed the footsteps of the cattle, climbed over the hills, walked into a small village, found the owner of the cattle, and inquired about the situation of the cattle with the owners. What the head of the household said was exactly the same as what Yuan Tiangang said, except that the cow had not yet given birth. Li Chunfeng personally observed the cow, as Yuan Tiangang said.
After a while, Li Chunfeng visited the head of the household again, and before he entered the house, he bumped into a blind cow under a tree outside the courtyard wall, which was tied to the trunk of the tree, and there was a small bull sucking milk under the abdomen. Seeing this scene, Li Chunfeng turned to leave, chanting "Strange! Amazing! ", obedience, capitalization, heart to take orally take out admiration.
Back at Yuan Tiangang's residence, Li Chunfeng humbly asked for advice, saying, "I have studied with the teacher for a long time, and I have never heard you teach such secret arts. ”
Yuan Tiangang said, "This is not a secret art. The cow is pregnant, and the one who walks with the left foot is heavy with the calf, and the right foot is heavy with the heifer. I saw that the footprints of the cow were left and right, and I concluded that it was a cow pregnant with a calf. Looking at the grass that had been chewed by the cow, only the right side was gnawed at a large piece, and it was concluded that it was blind on the left eye. ”
After hearing this, Li Chunfeng sighed, "Maybe I can learn your Daoist skills, but I can't catch up with your wisdom." ”
