1010 TIN-PLATES 



tion dissolve 1 ounce of granulated tin of Cornwall, observing not to put in a fresh 

 piece till the preceding be dissolved. 



Mordant E, by Scheffer. Dissolve 1 part of tin in 4 of nitro-muriatic acid, pre- 

 pared with nitric acid diluted with its own weight of water, and one thirty-secondth 

 of sal-ammoniac. 



Mordant F, by Poerner. Mix 1 pound of nitric acid with 1 pound of water, and 

 dissolve it in an ounce and a half of sal-ammoniac. Stir it well, and add, by very 

 slow degrees, 2 ounces of tin turned into thin ribbons upon the lathe. . 



Mordant F, by Berthollet. Dissolve in nitric acid of 30 B., one-eighth of its 

 weight of sal-ammoniac, then add by degrees one-eighth of its weight of tin, and 

 dilute the solution with one-fourth of its weight of water. 



Mordant x, by Dambourney. In 1 dram (72 grs.) of muriatic acid at 17, one 

 of nitric acid at 30, and 18 grains of water, dissolve slowly, and with some heat, 18 

 grains of fine Malacca tin. 



Mordant L, is the birch-bark prescribed by Dambourney. This bark, dried, and 

 ground, is said to be a very valuable substance for fixing the otherwise fugitive colours 

 produced by woods, roots, archil, &c. 



TZHT-PXi ATX2S. The art of coating copper with tin seems to have been known at an 

 early period. Pliny refers to this, and from his description it is probable the vessels to 

 be covered were dipped into melted tin, and the ' vasa stannea ' of the Romans were 

 copper vessels covered with tin. The difficulty of coating iron with tin was, however, 

 much greater ; and the process of hammering the iron into sheets sufficiently thin, 

 and cleaning the surface, which latter work had of ten to be done by filing, were serious 

 hindrances to the extensive use of the invention. 



The art of tinning iron appears to have been first practised in Bohemia, and about 

 the year 1620 to have been introduced into Saxony. 



Beckminn states that, ' in the year 1670, a company sent to Saxony, at their ex- 

 pense, an ingenious man named Andrew Yarrenton, in order to learn the process of 

 tinning. Having acquired the necessary knowledge, he returned to England with 

 some German workmen, and manufactured tin-plate which met with general appro- 

 bation. Before the company could carry on business on an extensive scale, a man of 

 some distinction, having made himself acquainted with Yarrenton's process, obtained 

 a patent for his art, and the first undertakers were obliged to give up their enterprise, 

 which had cost them a great deal of money, and yet no use whatever was made of 

 the patent which had been obtained.' About the year 1720 works for the manufacture 

 of tin-plates were established at Pontypool, and these seem to be the earliest of such 

 works in England which were permanently successful. 



In 1728, John Payne invented a process for rolling iron. This seems to have at 

 once led to the use of the flat or sheet rolls for the manufacture of iron for tin-plates ; 

 but it is very remarkable that no further progress was made in this discovery of roll- 

 ing iron until 1783, when Henry Cort invented the grooved rolls. This discovery 

 was not appreciated for some years. Mr. Eeynolds, of Ketley, erected Cort's rolls 

 in 1785. In 1790 Henry Cort was engaged by Mr. Richard Crawshay to erect the 

 mills at Cyfarthfa, and, soon after, this important improvement in the iron manufac- 

 ture was generally adopted. The writer proposes to give in this paper a short resume, 

 first, of the process for cleaning and tinning the iron-plate, and after, of the methods 

 of preparing the iron for this purpose. 



The aifinity of iron for tin is much greater than is generally supposed. The point at 

 which the metals cohere is no doubt an actual alloy; and advantage is taken of this 

 by the manufacturers of articles for domestic use, made in iron as bridle-bits, com- 

 mon stirrups, small nails, &c. When the iron, whether wrought or cast, is perfectly 

 clean and free from rust, and brought in contact with melted tin, at a high tempera- 

 ture, an alloy seems to be at once formed, protecting the iron from oxidisation whilst 

 the tin lasts. Many plans are used for tinning iron articles, of small size, by the 

 manufacturers. One of the common methods of the manufacturers of bridle-bits and 

 small ware, in South Staffordshire, is to clean the surface of the articles to be tinned, 

 by steeping them for sufficient time in a mixture of sulphuric and hydrochloric acids, 

 diluted with water, then washing them well with water, but taking great care they do 

 not rust, at once placing them in a partially closed stoneware vessel (such as a com- 

 mon bottle), which contains a mixture of tin and sal-ammoniac. This vessel is 

 then placed on a smith's hearth, duly heated, and frequently agitated to secure the 

 complete distribution of tho tin over the iron. The articles, when thus tinned, are 

 thrown into water to wash away all remains of the sal-ammoniac ; and lastly, cleaned 

 in hot bran, or sawdust, to improve the appearance for sale. 



The plans of cleaning and preparing the iron for tinning have undergone many 

 changes in the past century. About 1720 the plan of cleaning was to scour tho 

 plates with sand and water, and file off the rough parts, then cover with resin, and 



