Engineering Sphere

Back when I was a (delusional) engineering student, I had to take my fair share of physics classes.  Some might say slightly more than my fair share.  One of my professors had an odd and somewhat alarming propensity to set us problems that involved livestock.  Cows on ice skates.  Sheep in catapults.  Horses on pogo sticks.  The imagery was actually quite disturbing and rather makes me wonder about his misspent youth.  Each of these problems would end with the line, ‘for ease of calculation, assume the animal is a sphere.’

Now the distinction between a mathematical sphere and an engineering sphere is a fine one to make.  They aren’t the same thing, and knowing which one you’re dealing with can have all sorts of real-world ramifications.  But the habit of assuming livestock are all spheres tends to lead to fits of giggles whenever I drive past a field full of critters.  The Boy was in this class too, and ‘engineering sphere’ is still part of our household lexicon.

All of which is my rather rambling and indirect way of bringing me to the topic of your thumbs.  Bear with me, there is a connection.  Take a second and lay your hands flat on a table or desk or wall.  See how your thumbs stick straight out from the side of your hand, it’s in a plane with your other fingers?  Ok, now pick your hands up and hold them relaxed in front of you.  See how your thumbs are no longer sticking straight out of the side of your hands but are instead a bit closer in toward your palms?  Yeah.  That’s where your thumbs spend most of their days.

This thumb placement thing becomes important when you’re thinking about knitted hand coverings.  It comes up for me in fingerless mitts, but it would be important in gloves or mittens too.  You know how some pairs of mitts seem to constantly be twisting around your arm?  How the back part isn’t ever centered right when you’re wearing them?  And if it is then the underside of your arm is all twisty?  Yeah.  A lot of that goes away if you remember to put your thumb stitches a tiny bit in towards your palm, instead of straight out to the side.  Take a look at these.

That guy in the front, he’s got his thumb sticking straight out to the side.  Exactly like your thumb doesn’t usually do.  And see how the fabric looks a bit bunched up and shoved over and uneven (hard to convey in a picture, but I had to fight to get it as smooth as it is, and even then it’s wanting to twist).  Now look at the dude in the back, he’s got his thumb set a bit forward of his fingers.  That’s where your thumb usually hangs out.  See how the fabric on the back of the hand looks smoother and straighter?  These mitts have their thumbs tucked under, just the littlest bit.  That means they look awkaward when they’re on a glove form with his thumb sticking straight out, but look very good on a glove form with his thumb in a more natural position (or, say, on a human hand, which is likely more important).

Pretending your thumbs stick straight out the side of your hands may make the calculations easier, but it’s about as accurate as pretending that cow is a sphere.  Move your thumb stitches in towards your palm, just a tiny bit (really, it can be as little as a stitch or two), and you’ll find your mitts don’t twist around and fit much better.

The Mysteries of Gauge

On a lot of my recent patterns, I’ve included a wee little chart like this.  The shaded column on the left is gauge (in stitches per inch).  The shaded row on the top lists the various sizes the pattern is written in.  The cells in the middle tell you what size finished object you’ll get if you make a given size at a given gauge.  So with this chart, if you were working at a gauge of 4.5 stitches per inch, and you make the size medium, you’ll get a hat with a finished size of 20 inches.

This demonstrates one of the most basic things about knitting, and one of the things I think a surprisingly large number of knitters haven’t quite internalized.  You can really fine tune your sizing through yarn choice and gauge. Now this isn’t magic (it’s math) and it doesn’t work for everything.  But it is an awfully handy tool to have in your box of tricks when you want to nudge the size of something just a bit.

The socks I’m working on now are a perfect illustration of this.   Let’s look.

The gray socks on the top have a 64 stitch foot.  The blue socks on the bottom have 54 stitch foot.  Yet as you can see, the blue socks are quite a bit bigger than the gray socks.  This is because the gray socks are worked at a gauge of 8 stitches to the inch, and the blue socks are worked at a gauge of 6 stitches to the inch.

This only works because the socks use radcially different yarns.  The gray socks are a traditional sock weight, and the blue socks are a heavy dk. So both socks are knit up at an appropriate density (nice firm fabric suitable for socks) for the given yarn.  You can’t just use the gray yarn at 6 stitches per inch (it would feel like walking on little wires, and it would wear through in a few hours) or the blue yarn at 8 stitches per inch (you’d break your needles and the fabric would be stiff like cardboard).

But, with a bit of planning, this approach can let you use a wider range of patterns and yarns than you might think.  Let’s say you’ve fallen madly in love with a  pattern that comes in a 64 stitch size and calls for a gauge of 8 stitches per inch.  That gives about an 8 inch sock.  What if your feet aren’t 8 inches?  If you’ve got bigger feet, pick a thicker yarn and work at a gauge of closer to 7.5 or 7 stitches per inch.  If you’ve got smaller feet, pick a thinner yarn and work at a gauge of closer to 8.5 or 9 stitches per inch. This trick lets you fine tune the final size without having to adjust the pattern itself.  Especially for something like a sock where a half inch one way or the other can make all the difference, it works beautifully.

Now I can’t speak to the skinny yarns (I’ve got big feet and I’m a lazy knitter), but I have a nice little list of excellent thick sock yarns.  I’ll come back and post them later if people are interested (and I’d love to hear from you folks with tiny feet or more patience about which skinny sock yarns are your favorite).

Unreasonably Helpful

I went ahead and added the elastic, and it made a huge difference.  I used Dritz Thin Beading Cord Elastic which I found at my local Joann store for all of $1.59.  I ran four strands of it through the knit stitches on the inside of the hat’s ribbing at the brim, one each at the first, third, fifth, and seventh round of stitches.  It took all of five minutes and it has totally improved the hat beyond all reason.  It is now just the right kind of snug…not tight enough to leave marks on my forehead, but not loose enough to slip off my (unreasonably straight and slippery) hair.

If you’re considering doing something similar to one of your hats, I have a few small suggestions.  First, cut the elastic several inches longer than your actual head circumference.  In this case, the cord came in three yard lengths, so I cut it into four pieces of twenty seven inches each.  Run the elastic through the ribbing.  Line up all the ends on one side and tie them in a loose overhand knot, leaving a bit of a tail.  Tug and stretch the hat till you think the elastic is the length you’re going to want, tie the other ends in another loose overhand knot, and do not cut off the extra length.  Wear the hat for a while.  There’s a good  chance you’ll decide the first length wasn’t quite right and you’ll want to adjust things a bit.  I ended up loosening mine twice before I found the perfect size, and I was glad of the extra length.

If you look closely you can also see one of my dirty little knitting secrets.  When I knit in the round, all my purls are twisted.  Please do not explain to me why this is wrong and bad and terrible and how it is likely to cause the world to end.  I understand why it happens.  I know how to do them so they don’t come out twisted if I want to.  I just like them this way.  I find it easier and faster to do, and I knit so loosely that the extra bit of snugging up that the twists provides is helpful.