December 17, 2017 Sunday
Bedtime Story
Understanding Weaving
One of his first inventions goes by the
name of treadle loom.
Now I am aware that most of us are not in
textile business and so I would not expect any of my story readers to know what
a loom is, least of all what a treadle loom is.
Yet, it is something that we need to know
since now it is a vital part of our story and without it you may not appreciate
one of the important principles that went in the theoretical construction of
analytical engine.
I shall presume that most of us have never
ever seen a loom in our lives and even if accidentally seen, never took any
interest to closely observe and study its workings.
What does a loom exactly do?
Well, to describe a loom and its workings I
will be using two technical terms “warp” and “weft”.
We all know that clothes are made
essentially from threads.
In textile industry, threads are technically
called yarn which is nothing but long continuous length of interlocked fibers
very commonly obtained from the plant fiber called cotton.
Weaving is the process that converts yarn
into fabric and the two basic components of weaving are warping and wefting,
sometimes also called woofing.
Warp are the vertical threads stretched
taught on a rectangular frame which is otherwise the loom and the second set of
threads are called weft that goes back and forth between the warp at right
angle to them.
Every time the weft goes through, the warp
moves in to trap it snugly and compact thereby creating a fabric.
So warp is the longitudinal set of yarn
that is stretched in place on a loom under high tension in a weaving process.
Weft is threaded transversely through the
longitudinal fibers alternating over and under them.
Obviously you see the problem here; that this
can be an extremely tedious process if done manually for each yarn that will
run transversely and even more so if the pattern desired on the fabric is
complicated and colorful.
In the most simple weaving process such as
a plain white cloth, this movement of the weft yarn going above and below the
warp yarn is achieved by raising simultaneously every other warp yarn.
The space that is created between these
raised and lowered warp yarn is called the “shed”.
Through this shed the weft yarn is passed
transversely.
Once it goes through, its path is revered
by a complete U-turn.
Following this, the set of raised warp yarn
is lowered and the alternate warp yarn set is raised and the returning needle
passes through the shed in reverse direction now.
After each horizontal movement of the weft
needle, the loom closes in thereby converting the long thin isolated yarns into
a velvety fabric.
This cycle, when it proceeds on for
thousands of times, results in the creation of complete large fabric that can
later be cut and tailored.
Stay tuned to the voice of an average story storytelling
chimpanzee or login at http://panarrans.blogspot.com
Good night mon ami and my fellow cousin ape.
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Another great educator and a teacher that I am aware of is
Professor Subhashish Chattopadhyay in Bangalore, India.
While I narrate stories, Professor Subhashish an electronic
engineer and a former professor at BARC, does and teaches real mathematics and
physics.
He started the participation of Indian students at the
International Physics Olympiad.
Do visit him here:
All his books can be downloaded for free through this link:
For edutainment and English education of your children, I
recommend this large collection of Halloween Songs for Kids:
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