## McMorran’s Math

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Last week I had two guest speakers in my Thinking Mathematically class.  They came to talk about how math is used in the fiber arts, particularly clothing design.  For example, shawls made in different places combine simple geometric shapes in different ways to come up with styles that serve different purposes, depending on the styles and needs of the people involved (only they said it without using the word “different” three times in a single sentence because they’re professionals). Or how to use proportions to design a sweater, or even how to use the relationship between the circumference of a circle and the radius to create a design for a circular shawl by doubling the number of stitches whenever the number of rows has been doubled.

At the end, they showed me a doohickey called a McMorran Yarn Balance. Both Mary Louise and Meg are spinners as well as knitters and dyers, and when you spin your own yarn, this McMorran Balance can tell you how many yards of yarn you’re getting per pound!

Godzilla is here to show you how it works.

First, you take the Yarn Balance out of the box and set it up. It’s a rectangular prism with grooves for the balance part. There’s a notch in the balance part itself, and that has to be face up because it’s where the yarn will go.

Then you take a piece of your yarn and drape it in the slot.  Get out your scissors, because you’ll need those next!

Now carefully trim the yarn until the balance part is completely balanced.

Now you take that little piece of yarn that is perfectly balanced, and you measure it in Inches. Because this in an Imperial Yarn Balance (which sounds a bit like Imperial Storm Troopers, but there are none of those around. And if there were, Godzilla could totally take them.). They also sell Metric Yarn Balances.

This piece of yarn measures 4 inches. Multiply that by 100 {that’s the mathy part of this post} to get 400, and that’s how many yards of this yarn there are in one pound! Most yarns actually have a higher number of yards per pound, but you can see that this yarn is kind of thick so it’s a little heavier (meaning that it doesn’t take as much length until you have a pound).

I totally wish that I were the person who invented this balance and figured out exactly where the notch would have to be so that you only have to multiply by 100. Sadly, I can’t find anything about the history of this device online, so I don’t know who to thank for this little creation!

Thanks to Mary Louise and Meg for coming to my class again and sharing your talents!