It seems probable that the kiln was first used in Mesopotamia as long as 6500 years ago.
The kiln brings many advantages with it. Firstly it can be used to bake bread which, as well as being nourishing, is a way of storing grains in a readily digestible form for days on end. Some consideration will be given to the role that baking played in the rites of passage of a child into womanhood, but that will be to come.
With the kiln pottery becomes far more durable than simply being sun baked. Bricks can be made that will be much tougher and more stable than sun-dried ones.
It is necessary to control the heat and constancy of the fire. This is no mean task and leads to technologies of its own including bellows, chimneys, smoke stacks, air vents and various design features.
In the process it will have been noted that certain clays created a patterned effect that later came to be called ceramics. Strange glistening jewels of fragments of colour quite unlike anything else but precious for all that.
This too will lead to experiments with various ores and soon the art of smelting comes into being. How long this evolution of the art form took cannot be judged. One thing is certain once a new technology such as the kiln has been introduced it will be quickly adopted by others who will have explored similar technologies of ovens and bake holes to create their own breads and roasted meats.
As the technology crosses linguistic and cultural boundaries it will carry its lessons and language with it. Even if the words are not imported unchanged the concept they carry will be. For example wheat is a grain that produces a white flour. Indeed it is evident that the two words are directly related. However when the grain and its technology came into Welsh it became, not ‘wheat’ and ‘wheaten’ but ‘Gwenith’. The Welsh for white is gwyn, hence the idea was carried across if not the word itself. However in English the ‘wh-’ start to the question words is generally taken to represent an earlier theoretical form ‘kw-’ and ‘kw-’ is not very far from ‘gw-’. Nevertheless the principle stands that a technology will carry with it its ideas and often its language. We still use the word ‘aqueduct’ in English to mean ‘artificial water channel’.
Both of these technologies, the kiln and water control were developed in Mesopotamia to feed the cities that grew there as early as 5000 BC. This was the centre of grain production and irrigation prior to the development of those same features in Egypt.