Where are the mistakes?

Every time I knit from a vintage or antique pattern, I prepare myself to run into lots of mistakes in the pattern itself. Of course, not every vintage pattern is riddled with errors, and there are plenty of contemporary patterns that are full of them. Personally, I think this cautious sentiment stems from looking though mid-19th century pattern books, which so often contain a disclaimer that, although great care has been taken to prevent mistakes in printing, there will necessarily be some errors and that it is the knitter's responsibility to find and correct them. The publisher basically takes no responsibility for the home knitter's bad results from error-filled patterns. That doesn't exactly fill one with confidence.

So, I've always just expected mistakes. I look at each measurement, stitch count, and decrease with great suspicion. I do all the math. I count all the stitches. I interrogate each instruction. And if I don't find mistakes in a particular pattern, I start to doubt myself, as if I've overlooked something obvious if I haven't spotted an error. So far, my Ladies' Outing Coat instructions have been error-free, which has inspired in me a fair amount of distrust. Where are the mistakes? Have I missed them?

Fortunately, I worry no more. I have found some mistakes and weird math in the sleeve instructions (wahoo)! I have the strange sensation of feeling both confident and trepidatious: I found the mistake (all is right with the knitting world again), but now I'm concerned about the outcome of my sleeve. The pattern calls for a cast-on of 50 stitches, followed by increases of 2 stitches on both ends of the needle every other row until there are 100 stitches total; this forms the top of the sleeve. This is impossible since 50 is not divisible by 4 (haha! mistake! I knew you'd turn up). It also seems doubtful that the pattern would be uneven in this way, so I decided to work until I had 102 stitches. I considered the possibility that the mistake was something more than a simple typo, but the sleeve cap seems to look right so far. So, on we go.

In thinking about this mistake, I did also check a couple other sources for solutions. Unfortunately, no one has posted projects from this pattern on Ravelry yet. I wondered if later editions of the Columbia Books of Yarns might have the same pattern with updated instructions, but my search didn't turn up any later versions.