Daomu Biji: Wu Xie’s Private Notes

What I was most interested in was how Wang Zanghai built this ice shell, because it was actually an architectural paradox. If the ice shell was built first, then this was equivalent to a castle in the sky. If there wasn’t any support, then I really couldn't think of a way to complete the arc of this ice dome without it collapsing.

If the wooden piles were put in place first, then that meant that the piles were only supported by ice at both ends. But it was impossible to support such huge wooden piles with ice alone.

After thinking long and hard about it, there was actually only one possibility—it was originally a large glacier. Wang Zanghai first had craftsmen dig tunnels in the glacier, insert piles into the tunnel, pour water into it, freeze it, and then cut the dome out bit by bit.

It seemed that this required not only precise calculations, but also very careful engineering planning. But when I thought about it, I found that this engineering technique was the most time and labor efficient method, and could even be said to not be very difficult. Compared to building the palace with ice bricks, this method ensured that the workers didn’t need to have a lot of experience like craftsmen did.