From 2004 to 2007, he traveled around Sichuan, Shaanxi, Guizhou, Jiangxi and Zhejiang provinces and Chongqing, collecting information about 200 ancient devices, making sketches of them to catalog traditional folk craftsmanship.

Using his mechanical drawing skills, he has spent 400,000 yuan ($62,760) of his pension to restore or reproduce 20 full-scale devices since 2016.

Most of the agricultural devices he has restored or reproduced can be found in The Exploitation of the Works of Nature (Tiangong Kaiwu), a technical encyclopedia published during the Ming Dynasty (1368-1644).

Another of them－the Nine Water Mills－which is depicted in the Book of Agriculture by Yuan Dynasty (1271-1368) agronomist Wang Zhen (1271-1368), is 10 meters long, 5 meters wide and 6 meters high.

In addition to studying traditional Chinese science and technology, Tang has come up with designs for about 1,000 souvenirs and handicrafts over the years, most of which are in commercial production. His hands are rough from years of manual labor.

"The Qin Dynasty (221-206 BC) lasted for only 15 years, while the Han Dynasty, which attached great importance to science and technology, lasted for over 400 years. That means science and technology might play an important role in the stability of society and economic development," he said.

Li Zuolin, a teacher at the High School Affiliated to the Renmin University of China and an expert on curriculum reform, said: "This elderly gentleman (Tang Jialu), who has had a genuine enthusiasm for keeping ancient science and technology alive his whole life, is admirable."

Nearly two years ago, Li met Tang in Beijing and was astonished by his work. He said that Tang has not only produced systematic written research into ancient science and technology, but has also come up with actual inventions that could serve as teaching resources for students and have far-reaching significance.

"The country is paying more attention to labor education, which is a good thing," Li said.

On March 20, 2020, the State Council, China's Cabinet, issued an initiative on strengthening labor education in colleges, secondary schools and primary schools. It calls for integrating labor education with training at school, at home and in society, to help students understand the unity of knowledge and practice, and form a correct worldview, outlook on life and values.

"Culture is the soul of a nation. We need to draw strength from traditional things," Tang said.

He said he hopes to build a museum large enough to display hundreds of replicas of ancient devices, including those used in agriculture, wind power and metallurgy, and in making textiles, earthenware, ancient vehicles and weapons. Currently, he is searching for a suitable place and investment.

"My hope is that this will give young people a better understanding of our long history, encourage them to contribute to Chinese civilization and strengthen their cultural confidence," Tang said.