HISTORICAL NOTE. 9 



The first improvement in the tin can, adapting it especially to 

 canning purposes, was made in 1823 by Pierre Antoine Angilbert, a 

 Frenchman. His improvement consisted in first putting the fruit and 

 water in the can and covering it with a lid having a hole in it. The 

 cans were set in a water bath and boiled for some time, after which 

 the hole was closed with a drop of solder. The first patent on a tin 

 can to be issued in this country was in favor of Mr. Thomas Kensett 

 in 1825. 



All the early tin cans were made by what was known as the plumb 

 joint; that is, the edges along the sides were butted together and 

 soldered, as were also the two ends. The entire work was done with a 

 pair of scissors and a soldering iron. Only a few cans could be made 

 in a day, 100 being considered a very large number for one workman. 

 It was not until 1847 that Mr. Allen Taylor invented the stamped 

 can with the extension edges. In 1849 the pressed top was added as 

 an improvement. 



From the beginning, bottles were too costly and broke too easily to 

 be used for the cheaper articles of food. The earthenware jars were 

 heavy and not sufficiently well glazed. The tin can lent itself to com- 

 mercial purposes best, but it was expensive and the evolution of its 

 manufacture was slow. At present it is manufactured by automatic 

 machinery at low cost and in enormous quantities. 



At first the temperature employed in canning was from 190 to 

 212 F., but this was found to be insufficient for many products. A 

 higher temperature was secured by adding salt to the water in the 

 bath, and later this was gradually supplanted by calcium chlorid. 

 With the latter it was possible to secure a temperature of 240 F., 

 thus shortening the period of cooking and also making it possible 

 to process some products which could not be sterilized by boiling 

 alone. It was not until 1874 that Mr. A. R. Shriver, of Baltimore, 

 invented the closed-process kettle for cooking with superheated 

 water. About the same time, Mr. John Fisher, of the same city, 

 patented a kettle in which live steam could be used. These same 

 methods, boiling in water in the open, in a bath of calcium chlorid 

 (now being superseded by oil), in superheated water, and with steam 

 in closed kettles, are still in common use, the only difference being in 

 certain modifications for doing the work easily. The most recent 

 addition to the equipment for heating is an agitator, which has the 

 effect of stirring the contents inside the cans so that all parts are 

 heated uniformly and rapidly, and is advantageous for certain 

 products. 



Shortly after Appert's method had been published and the tin 

 can found to be suitable as a container, small canneries were estab- 

 lished in Aberdeen, Scotland, in Sligo, Ireland, and in European 



