trade is gradually falling off. The enamelling, known as cloisonné is performed as follows: The decoration, birds, flowers, &c., is traced on the surface of the object to be enamelled, very thin wire of any metal, but generally silver or copper, is then bent by hand to the various forms traced on the metal. This process requires the utmost care. The wire thus bent is then soldered down to the surface of the object, the different colours put in in the form of paste into the different divisions formed by the bent wire, and the whole is subjected to intense heat until the colours are completely fused. When cold the surface is rubbed down flat, and finally polished. In the champlevé process the spaces for the colours are cut out with a graver. The process of damascening largely carried on by Messrs. Elkington is described at (B. 545.) Soldering arrangements are much improved, the introduction of the patent blowpipe saves time, and the workman is able to solder, cleaner and produce a firmer jointing than with the old process. The sand blast is a new feature in the finishing department. =Refrigeration.=--[S. PUPLETT.]--Mechanical refrigeration owes its development to the enterprise of Birmingham men. The imports of ice into the United Kingdom were in 1884 nearly 300,000 tons. Refrigerating machinery is supplying ice in competition with these importations. In addition, refrigerating machinery is used in brewing for the purpose of cooling wort quickly, in bacon curing, in working of butter and butterine, cocoa, and candles, in oil refining and tar distilling, and in telegraphic works for securing a low temperature when testing cables. Freezing machines have too been used in sinking and tunnelling, the water being prevented from running into the shaft owing to the hardening of the earth by freezing. The cost of imported ice may be taken as 20/- per ton, while machine ice can be made for 5/- per ton. The first commercial machine, patented by James Harrison, of Geelong, in 1856, was an ether machine, and made in London. Afterwards machines of this kind were made by Mr. Philips, of the Atlas Works, in Oozells Street, Birmingham. In 1861 Carré showed the advantages of ammonia over ether as a refrigerant, and since then Mort and Dicholle, of Sydney, and Stanley, of London, have patented various modifications of the Carré system. Pictet has devoted many years to the subject, and has identified himself with sulphurous acid as a refrigerant, and recently claims to have discovered a fluid termed _liquide Pictet_, SCO₄; in addition to these refrigerants, air, water, chloride of methyl, bisulphide of carbon, carbonic acid, and nitrous oxide have been used. The machines made in Birmingham by the Birmingham Refrigerating Company are ammonia machines. This form of machine consists of (1) a multitubular vessel called the refrigerator, containing liquid (anhydrous) ammonia--in this vessel vaporization takes place; (2) a