@John1 - Thanks for the welcome! Unfortunately, I also don't have a decent set of calipers... although I do need to put in an order and may pick up a decent but not too expensive set. However, I am an engineer by heart & trade (computer software & hardware, specifically) so... lemme dig around the office...
@JimmyD - Thanks for the comment, although I did address the "oblong" nature of the pictures as due to using strong side light, and the bottom of the coin is a heavy shadow. I found it odd that the heavy shadow looked almost exactly the same color as the coin, it isn't. I included a non-lit picture of poor quality to try to show that the coin is in fact quite round. However... it's not a good picture, so... lemme dig around the office...
Mmmkay. Here's what I got. I have a well worn 1972 US George Washington quarter
(Good to Very Good, I'd guess, unimportant, tho.). I also have an adjustable wrench (spanner, for the Brits :-) ) with a gauge and something to prop it up against. So, my method is this: I compared the Large Cent to the US quarter, it's slightly smaller in diameter. As I doubt the quarter will be worth more than 25 cents US, I put it in the adjustable wrench and tightened it as much as possible, to use the quarter as a "backdrop" for the large cent, propped up the wrench as vertically as possible (but not perfect, this is all freehand), then very, very, *very* gently set the large cent in front of the quarter, and it "slid right in" with a small amount of leeway. Took a couple pictures as best as I could with a) natural light, and b) my cell phone camera. Slid 'em over to my desktop, picked the best I could see, and sparked up Gimp, to see how to get the best quality & size combined under the 300KB limit of the forum. With some judicious cropping and using a fairly high compression (which still kept the details I was interested in) I was able to scale the image down minimally.
You can see: 1) a little bit of the GW quarter peeking out from behind the large cent, 2) the base of the large cent is in fact quite round (albeit not quite perfect, I suspect not having enough metal to fill the die to the rim has a bit to do with that) and 3) in the upper left hand corner of the picture there is a (admittedly not as accurate as a digital caliper) scale on the wrench, presumably for measuring the size of the bolt/nut you're working with so you can grab the correct sized box-end wrench the next time. (could be handy if the head of the bolt is out of sight.) Took a 2nd picture of the ruler of the wrench. As 15/16" is 23.8mm and a Washington quarter
is 24.3mm (albeit the one I used the reeding was almost all worn off), this shows (without digging into the collection to find an actual Canadian quarter of the period) that 23.6mm is "really gosh darned close" to the size of my large cent.
Images [[ I hope the first isn't too big (resolution-wise) for the forum... ]]:
I'll update the post when I receive more/better equipment for a more detailed analysis.
I guess on that note: Any recommendations for a good coin scale? Would a single-serving tea scale work, or is that still not good enough? Not looking to spend a mint on it, tho -- $30ish?