The refrigerator is one of the most brilliant inventions in the history of mankind. The refrigerator is a product of eventual inventive evolution. Since time immemorial, humans were in a quest to preserve food. The changing seasons and the extreme weather conditions made methods for food preservation of utmost importance. Over the years, food preservation techniques thrived among the various groups of people all over the world. Food preservation techniques were according to the respective weather and seasonal changes of the different regions and localities. These also varied according to the kind of food being preserved. Livestock, fruits, vegetables and all other edible things vary according to regions and so the technique employed to make these foodstuffs last is as varied as the kind of food which were to be preserved. Food preservation, perhaps, is one of the more important reasons why humanity managed to survive and thrive throughout the millennia.

The ancient Egyptians used salt to preserve food (and yes, corpses as well. But that's a different story entirely). Eventually, the method of making pickles as a preservation technique for fruits and vegetables, gained popularity among the western and the near eastern countries. These methods evolved from the simplest to the more complicated forms. There are other regions where they stored food in cellars where the air is cooler. Of course there are other techniques like smoking, or canning et cetera.

The downside of pickling and salting and smoking is that the taste of the food changed. Fish and red meat had to be salted to prevent it from spoiling over the long winter season. Salting, of course, makes the food salty. So unless, you eat the fish a little after catching it, you would have to contend with eating salted fish (which can be revolting after eating them for so long) until the next fishing season comes. Sad for your taste buds and sadder still for your health. So people had to think of a better way to preserve food without changing its taste drastically.

Enter the concept of the refrigerator.

Refrigeration uses the principle of lowering the temperature of the food to be preserved to prolong its life and prevent it from spoiling. Very low temperatures prevent bacteria from thriving along the surface of the food thereby making the food more edible longer than when left on a shelf at room temperature.

The earliest style of refrigerating came in the form of ice houses. Natural ice was harvested in the colder regions of a particular country and placed in a store house. The natural ice made the store house cold, obviously, and so people were able to store their foodstuff there. Meats, particularly. And then they thought of the miniature version of these store houses-- ice boxes. The same principle of harvesting natural ice were employed. Only, they were placed in boxes. But the ice had to be replenished and the melted ice emptied everyday. This made everything tedious.

Refrigerators slowly evolved into the refrigerator we know now by artificially manipulating the temperature and lowering it to preservation levels. They started off with using ammonia and other chemical fumes to make cooling possible. This however made the refrigerator toxic. It wasn't only until the second world war when refrigerators came to be safe and free of toxic chemicals while efficiently compressing air to cool the enclosed area.