Mr. Wang：Let’s go see the main attraction, the Icehouse.
Ska: The Icehouse!
Mr. Wang：Yes, the Icehouse.
Ska: The royal Icehouse?
Mr. Wang: Yes.
Ska: Mr. Wang, please take us to have a look.
Mr. Wang: Sure, let’s go.
Mr. Wang: As we walk downstairs,we’re entering the Icehouse. First, let’s have a look at this side. We can see the wall here is very thick, about 1.4 meters.
Ska: The thickness is 1.4 meters, right?
Mr. Wang: Yes.
Ska: Why is the wall so thick?
Mr. Wang: Mainly, the thickness of the wall helps to isolate the air in the Icehouse from the air outside.
Now, let’s take a look at this.It seems very old. In the past when there was no electricity, people needed to use this kerosene lamp to help guide them down the stairs. This was used for keeping the door closed. Chinese people used big battens as a bolt.
Mr. Wang: Yes, to keep the door closed. Just like the gate locks we use today.
Ska: Where’s the bolt?
Mr. Wang: It’s unfortunately been lost. Let’s go downstairs.
Now the stairs are suitable for use, but they used to be very steep.
Ska: Was the basement as cold in the past as it is now ?
Mr. Wang: Actually, as I said, the first layer of the wall is made of brick and you can see the cement surface. If we removed the brick, we’d see the granite underneath.
Ska: Granite can help maintain the cool temperature?
Mr. Wang: It’s that kind of stone that’s helpful, yes. If we remove the granite, we would see large cedar stakes.
Mr. Wang: They are underneath the granite.
Ska: They are wooden stakes, right?
Mr. Wang: Yes, cedar stakes. In China, during the past thousand years, cedar was used to make water conservation facilities.
Mr. Wang: It’s a special kind of wood.
Ska: Well, how old is it?
Mr. Wang: It’s at least...in my calculation,around 600 years old. Here, touch it.
Ska:It doesn't erode when exposed to wind or rain?
Mr. Wang: Here, underneath the granite, there are more than ten thousand cedar stakes. More than ten thousand.
Ska:The wooden stakes?
Mr. Wang: They were all hammered into the ground.
Ska: Standing vertically?
Mr. Wang: Yes, vertically. Obviously, every year has four seasons. Commonly, basements are warm in winter and cool during the summer.
Think about it, though. If the Icehouse is warm in winter, it can’t store ice. How is the basement insulated? People use this.
Ska: How does it absorb heat?
Mr. Wang: It doesn't. You’re familiar with the torch?
Mr. Wang: After you light the torch, you can carry it with you for a long time. It won’t burn your hand. Why? Because wood is a poor conductor of heat.
Ska: How to insulate basement from the heat?
Mr. Wang: As I mentioned, the wall here is very thick.
Ska: We have thick walls all around us. People in the past.
Mr. Wang: Yes.
Ska: It was made by hand, one brick after another.
Mr. Wang: Yes!
Ska: How old is the Icehouse?
Mr. Wang: To understate, one or two hundred years.
Ska: One to two centuries. From Qing Dynasty?
Mr. Wang: The late Qing Dynasty, yes. Just after the middle of the Qing Dynasty.
Ska: Why is the roof arched like this?
Mr. Wang: It’s a very special structure in China. The mechanical structure is totally dependent on the strength of the concrete.
Mr. Wang: As I mentioned, there were many wooden stakes underground. Ice was stored here during the winter months. The temperature of the ice was 0 degrees centigrade. The air in the Icehouse might be around four, five or even ten degrees centigrade. It didn't matter. As the temperature of the ice rose it gradually melted. At the same time, the temperature in the Icehouse would begin to lower. When the temperature in the Icehouse dropped to 0 degrees centigrade, the ice would stop melting. The heat outside couldn't reach the
ice because of the thick, insular walls while ground heat was kept out by the wooden stakes. As a result, the ice was stored easily and well.
Mr. Wang: All Icehouses have two doors. The one we just used was used as the exit during ice transportation. During the hot summer, when people needed the ice, it was removed using this door.
Mr. Wang: That small door, up there, it’s the door used to bring ice into the basement.
Ska: It’s so high above the floor. How was it used?
Mr. Wang: I’ll tell you. It was used as the entrance. The first piece of ice was stored there. During the summer when people used ice, this piece of ice went out first. The first one to come in was the first one to go out. It was very scientific.
Mr. Wang: Look at this. It’s an old remnant left in the Icehouse.
Ska: A ladder, right?
Mr. Wang: Actually, it’s not a ladder, it’s a board. We call it an ice sliding board. When it’s put there at an angle, the ice can easily slide down. This board is also around 200 years old. It’s around six meters long, and it’s in two separate pieces.
Ska: How many tons of ice could be stored in this Icehouse?
Mr. Wang: It wasn't counted by tons. It was counted in cubes. Theoretically, 2100 cubes.
Mr. Wang: The process of collecting ice involved harvesting it from the river. There were more than 20 workers.
Ska: The ice lasts the whole summer, right?
Mr. Wang: No. This Icehouse is one of the many royal Icehouses. There were another 17 Icehouses.
Ska: But there are only two left, right?
Mr. Wang: Oh, only this one has been preserved.
Ska: This is the only one?
Mr. Wang: Yes, it’s the only one. There are two more that remain, but they are not open to the general public.