A page from an antique Japanese manual, which was peculiarly written 75% in classical Chinese language (even this particular page was written in 100% Chinese), this is a Sword Striking Post for you to practice downwards cuts.
The top-most barrel is free-turning, but made of firm solid wood. When your vertical downwards stroke lands on it, it will rotate and your sword will continue its journey down. In the middle is another barrel, but made of leather and padded inside with cotton. This is where your stroke will end and land, with this barrel giving you a cushioning effect. The most bottom rectangular piece is just plain wood to hold this post in place.
This manual is "Gekiken Jintsuu Roku", written in 1768. You can get the entire manual as a reprint at: http://www.lulu.com/commerce/index.php?fBuyContent=22796427
Hope you found this interesting!
Ancient Chinese Martial Arts Manuals