BigCy ~ Nothing yet on the vaccination theory.
IronSpike ~ I thought the poultry (sucking them out of the barn and depositing them into a transport truck with a huge vacuum invention - Patent # 3,706,300) was crazy. But your chicken "glasses" are downright Twilight Zone!
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If I can explain the following properly, it may be of some help.
Dad pointed out that it was unheard of to have only one chicken per cage,(at least during the 1930s when the chickens ran around loose in large barns/houses), and later when cages were introduced, this number was at least ten or more per cage. Thus, the complication of being able to determine and keep track of which chicken laid which egg and how many. Of course, a couple of the inventions we've seen are counting devices that attached directly to the wing, but I for one still don't quite understand how those devices worked, other than to say they are probably not the item we are looking for.
I will confirm this next part with my dad later, but I believe he said the ranch he grew up on averaged about 5 thousand chickens. Which would be considered small by today's standards, but certainly adequate enough to support a family of five throughout the depression without hardship. He said their method of keeping track of an individual chicken's egg laying production involved removing it from the cage and isolating it in a seperate cage by itself. He can't recall how often they did this, nor exactly how long the chicken was isolated, but he does recall that in their particular case everything was recorded on paper, and not by means of any kind of counting device. But he admits the possibility that they were behind the times, or else these counting devices hadn't been invented yet.
In any event, he still believes the item in question is related to a "day/week" count, and not an "egg" count. And that it possibly may be the vaccination tracker he mentioned earlier, or an isolation tracker as just discussed. As for myself, I'm more confused than ever! I like both the egg counting idea, as well as the day counting idea. But, unfortunately, I cannot prove either one.
I hope this helps, and thank everyone on behalf of my dad who, I'm pleased to say, has taken a real interest in this topic. As soon as someone said "chicken," his ears perked up. Remember, he's 88 years old, not in the best of health, and spends about the same amount of time stuck in his reclining chair as I do in my office chair. I'm glad to see him get involved with something other than television.
Thanks again to all ~
Bob