"A short time before I left England, you published in the 'Gardener's Chronicle' a number of letters and plans for the construction of ice-houses, but, as far as I can remember, nothing at all resembling the Chinese one which I shall now describe to you. On the right bank of the Ning-po river, above the town and fort of Chinhae, and in various other parts of the north of China, I have met with these ice-houses. When I inspected them for the first time last winter (1843), their construction and situation differed so much from what I had been accustomed to see at home,—differing, too, in things which I used to consider as indispensable to an ice-house,—that I had great doubts regarding their efficiency; but at the present time, which is now the end of August, 1844, many of these houses are yet full of ice, and seem to answer the end most admirably. You are probably aware, from my former descriptions of the country, that the town of Ning-po stands in the midst of a level plain from twenty to thirty miles across. These ice-houses are built on the sides of the river in the centre of the plain, completely exposed to the sun—a sun, too, very different in its effects from what we experience in England,—clear, fierce, and burning, which would try the efficiency of our best English ice-houses as well as it does the constitution of an Englishman in China.
Ice-houses near Ning-Po.
"The bottom of these ice-houses is nearly on a level with the surrounding fields, and is generally about twenty yards long, by fourteen broad. The walls, which are built of mud and stone, are very thick, twelve feet in height, and are, in fact, a kind of embankment rather than walls, having a door on one side level with the floor, for the removal of the ice, and a kind of sloping terrace on the other, by which the ice can be thrown into the house. On the top of the walls or embankment a tall span roof is raised, constructed of bamboo, thickly thatched with straw, and in appearance exactly like an English haystack. And this is the simple structure which keeps ice so well during the summer months, and under the burning sun of China!
"The Chinaman, with his characteristic ingenuity, manages also to fill his ice-houses in a most simple way, and at a very trifling expense. Around the house he has a small flat level field connected with the river. This field he takes care to flood in winter before the cold weather comes on. The water then freezes and furnishes the necessary supply of ice at the very door. Again in spring these same fields are ploughed up and planted with rice, and the water which drains from the bottom of the ice-house helps to nourish the young crop. Of course here, as in England, when the house is filled the ice is carefully covered up with a thick coating of straw. Thus the Chinaman, with little expense in building his ice-house, and an economical mode of filling it, manages to secure an abundant supply for preserving his fish during the hot summer months.
"It now, I think, becomes a question whether we could not build ice-houses at less expense and more efficient, upon the Chinese plan, than upon the old under-ground system common in England. The accompanying sketch will enable you to form an idea of the appearance which these ice-houses present to the traveller, in going up the Ning-po river. Ning-po, August, 1844."
Since this letter was published I have had frequent opportunities of testing the qualities of the Chinese ice-house, both at Ning-po and also at Chusan and Shanghae, and I have found that it answers the purpose admirably. The winter of 1844–1845 was unusually mild in this part of China; little or no ice was formed on the ponds and canals, and of course the ice-houses could not be filled; but many of them contained large quantities which had been laid up the year before, and by this means the market was supplied with ice which had been in store at least a year and a half, and would probably have kept some time longer.