The measure of things

I started piano lessons when I was in the 2nd grade... ...but what does that have to do with woodworking? It was the first time I can recall that I was interested in the reach of my hand, tip of pinkie to end of thumb. The piano keys made a simple ruler for measuring hand size. After I got my full growth as a teen, my reach ended up at just a smidgen over 9 inches. Funny, I got this image from a Girl Scout site - the PDF is actually pretty useful, and exactly what I wanted to write about today.
It often happens that I need a rough measurement and don't have a rule in my pocket, or a tape measure at my belt. I often use my hand to get a rough measurement, often walking my hand along 9 inches at a time to measure something up to around 45 inches or so. But, hands come in all different sizes. Finding the reach of your hand, finding a 1 inch knuckle joint, walking heel to toe to pace off the dimensions of rooms based on the length of your shod foot - all great, all handy. But what if you need a more precise measurement, or one you can have someone at the other end of the phone use? What common objects are handy (snork) for everyday measurement?

For starters, paper money is good as almost everyone has a dollar near to hand. A piece of US paper currency is 6.14 inches long - close enough to 6 inches for most purposes. Folded in half it is 3 inches, in quarters it is an inch and a half. It is also 2.61 inches tall, but I never remember that.

Coins are pretty good too. A US quarter is 0.955 inches across, and 0.069 inches thick. Not so useful if you have a good eye for such things, or are already trained to instinctively use a finger joint to measure an inch, but really handy when relaying size information remotely. A dime is 0.7 inches across and 0.053 inches thick, but I don't find that as generally useful as remembering the size of a quarter and a dollar bill.  (added Sept 29, 09) I recently read that I neglected the cent!  A Penny is 3/4 of an inch across - well worth noting.

The last one pictured is simply the reach of your outstretched arms. Pictured is Leonardo da Vinci's "Vitruvian man" which was named after Vitruvius who was a Roman writer in the 1st century BC who set down ratios for human proportions. Bet you always wanted to know that, huh? (grin) So, however tall you are, that is generally the reach of your outstretched hands. The other measurements I like to be aware of is typical (Ok, favorite) chair seat, desk/ table, and kitchen counter heights - I measure those against my body. Perhaps not as handy as the above, but very handy when shopping for furniture. I really can't talk any more about it now, as it leads more deeply into the Golden Proportion / Golden Ratio!