Since the fifteenth century, the Chinese have produced salt by solar evaporation of salt water, according to a simple but satisfactory process. Pits are dug on the sea-shore and bamboos are laid crosswise over them. The whole is covered with double mats, and sand is strewn over the top. Every morning and evening the covering of sand is soaked with sea-water by the tide, and the salt liquor finds its way into the pits. As soon as the water has receded, the salt workers appear with flaming bundles of straw, to test the saline character of the moisture, which is not regarded as fully impregnated unless the salt vapour arising from the pits extinguishes the fire. The brine thus produced is drawn off and run into secondary or crystallizing ponds, the level of which is set a foot or so below the first series of pits. The secondary ponds, which are smaller and of less depth, are provided with carefully-rolled, hard clay bottoms. When a sufficiently thick crystalline deposit has been formed at the bottom of the secondary ponds, workmen, starting at the centre, scrape the bottoms, working outward spirally and finishing at the corner of the pond, where the coarse crystalline product is collected and allowed to drain. When drained and dried, the salt is ready for transfer to the market. In Japan, where the manufacture of sea-salt by boiling or by spontaneous evaporation was introduced more than two thousand years ago, the process is similar to that employed in China, but in some parts of the kingdom the evaporation basin generally employed in solar evaporation is dispensed with. In the latter method, a level field is formed close to the sea and sprinkled over with fine sand. Sea-water is then poured into the field, and, after evaporation of the water, the salt crystallizes and adheres to the sand. The mixture of salt and sand is next thrown into a kind of extracting apparatus and sea-water is poured upon it, whereupon the salt is dissolved and filtered in the form of a thick salt liquid. In other Japanese salt fields the concentrated liquor is poured into a crystallization basin prepared for the purpose, and, upon evaporation of the water by the sun’s heat, the salt crystallizes. [Illustration: ANCIENT SALT WORKS _A._ Wooden Ladle. _B._ Cask. _C._ Tub. _D._ The Master. _E._Assistant. _F._ The Master’s Wife. _G._ Wooden Spade. _H._ Boards. _I._ Salt-baskets. _K._ Hoe. _L._ Rake. _M._ Straw. _N._ Bowls. _O._ Bucket for Blood. _P._ Beer Tankard. _From an Old Print_ _Published in 1556_· ]