An Inch is An Inch

It's been raining the last few days, and while normally I go crazy when my beloved sunshine leaves for a few days, it's been kinda nice. I even learned something from it today.
Watching the rain fall in the back yard earlier, I noticed that the little water bowl we'd used to clean our brushes when painting the other day was full again. Just before the rain started, my four year old complained to me that our cat had drank all of his blue water, and the bowl was empty. So seeing the 2-3 inch bowl full again, I wondered if that meant we'd gotten 2-3 inches of rain in two days. It doesn't seem like it rained that much, so I decided to see how a rain gauge works and check my query.

An inch of water means an inch of rain.

So, yes, it appears we've gotten at least 2 inches of rain. But wait. What if that bowl had been wider? Would it have been as full? So again, I went looking for an answer.

If the bowl were wider, it would collect more water and the level would be the same.

Then I remembered seeing a rain gauge at a neighbors house once, and it looked like the picture I have above. Wider at the top and tapering down. So what's the deal with that?

Measuring smaller amounts of rain would be difficult if you used the Donna method, shown below, and since most of the time it rains less than an inch, the tapered gauge was created. By having a wider opening at the top, more rain can be collected, and since the bottom is smaller, you can measure smaller quantities using some mathematical ratio calculations that I am not going to get into right now.

Make your own rain gauge with these dandy instructions. You don't really need a dumb little website to show you how, but I thought the "To Print This Page" instructions were pretty funny, so check it out.

Amazing. No. Boring. But this is what I learned today.