CANNING INDUSTRY. Today one may enjoy at his own table practically every kind of fruit, vege table, meat, and fish obtainable for food in any part of the world. This can be done in summer or in winter—in the midst of tropical abundance, on the desert, in the bleak lands of the north, or on the long sea-voyages of sailing vessels.
Aside from the improved means of transportation, the tin can is the most important factor in this wide distribution of foods. Indeed the great variety of canned goods now on the market makes it possible to live almost entirely on " tinned" food. Every expedi tion of discovery and every army in the field in recent years has used canned foods as an important part of its rations. The traveler's way through the ness and across the desert is marked by empty tin cans, and a pile of tin cans grows by the side of each shack on the distant ranch or mining property. The empty tin cans of the country constitute a vast amount of waste. Fortunately the action of rust upon the iron in the tin causes it to break down and crumble before many years, so that the tin and iron are returned to the earth whence they came.
Tin Cans and Canned Goods in the World War Immense purchases of canned goods were made for the army of the United States in the World War.
Over a quarter of a billion cans of tomatoes alone were purchased—enough cans if placed end for end to reach more than around the earth at the Equator.
Nearly 40 million cans of evaporated milk and more than 118 million cans of meat were shipped for the army overseas.
In the trenches early in the war the humble tin can rendered a special service to the Allied soldiers.
When the hand grenades, which the Germans had manufactured in quantities for the purpose, began to rain upon their trenches, the Allied soldiers took empty jam cans, filled them with explosives and bits of metal, and so made a rough-and-ready grenade which served until supplies of regular grenades could be manufactured and shipped to them.
Our grandmothers did not have these convenient canned foods, for the preserving of foods in hermetic ally sealed containers is an industry of recent growth.
In earlier times the drying of foods was one of the chief methods of preserving it. Meats were dried and
smoked, and fruits and vegetables also were dried for winter use. Our grandmothers made quantities of thick jams, jellies, and sugar preserves and pickles of various kinds; but delicious as these were, they were too rich for ordinary food.
Growth of the Canning Industry In canning, the food is first sterilized by heat ing—that is, the bacteria which cause fermentation and decay are killed in this manner ; and the cans or jars are hermetically sealed to prevent fresh bacteria from entering.
The process of canning was introduced in the United States from Eng land and France early in the 19th century, but it did not become a general household practice until after the middle of the century. The first cans were very crude and it required an expert tin smith to turn out as many as 60 a day. The sheet tin was measured, marked for each can, and cut with a hand shears. Wher ever the tin was joined it was thought necessary to pile on a thick ridge of solder, and enough solder to seal a dozen cans as it is done today was used on one can. The cans are now stamped out in quantities by machinery and soldered automatic ally; and the inside of the can is acid-cleaned and coated with pure tin, so that it can be used for practically all kinds of canning. There was little demand for the canned foods until 1849 when the rush to the gold fields of California began. This was followed by the Civil War and the opening up of the West. These events caused a continuous and increasing demand for canned foods, because they could be transported easily, prepared without delay, and could be stored in quantities for future use without spoiling.
The Cans on the Pantry Shelf No sooner was a supply of cans available, more over, than the thrifty housewife back home began to take advantage of the new method, and the coming of winter found rows of canned fruit and vegetables, in addition to preserves and pickles, upon the pantry shelves. Now glass jars sealed with rubber rings are almost universally used in place of the old tin cans which our grandmothers sealed with sealing wax.