How did Deng Shiru practice calligraphy?

Deng Shiru devoted himself to learning calligraphy and worked extremely hard. He once lived in Jiangningmei's house for eight years. For eight years, he got up early every morning, before dawn, to grind a large plate of ink to prepare for the whole day. No matter how late it was, he would finish writing the ink before going to bed. Whether it is the scorching sun in midsummer or the cold days of winter, he never stops. He copied the pre-Qin "Shiguwen", "Taishan Carved Stone" and Li Yangbing's "Three Tombs" day and night, each of which amounted to hundreds of copies. He also collected inscriptions on bells and tripods, Qin and Han dynasty tiles, and tablet foreheads, and wrote 20 volumes of "Shuowen Jiezi". From here we can see how amazing Deng Shiru's energy was expended in studying calligraphy.