Thursday, February 17, 2011

Measuring Up

There were three tools that we needed to complete our data from the past season, and all three were scales.
We already owned one, the triple-beam balance pictured in the potato post of a few months ago. It serves many purposes, not the least of which is the fact that it is in metric.
Now the subject of which system of measurement is best can certainly be argued, but there's no denying which one is easier.
As an extreme example, imagine that you have an intern from a country that uses the metric system (which is actually every country except Myanmar/Burma, Liberia, and the United States). Now picture explaining to them how to calculate how much alfalfa they need to spread on 60 ft2, when we're applying it at the rate of 2 lb 7 oz per 100 ft2.

Ok, how many ounces are there in a pound? No, that's how many ounces are in a gallon - we're talking about pounds. Right, 16. So start by multiplying out our rate to get it all in ounces. 2 x 16 is 32, plus 7 makes 39 ounces. That's for 100 ft2, and we want it for 60 ft2, which is .6 of 100 ft2, so multiply the 39 ounces by .6. Yes! Very good, that's 23.4 ounces. No, we're not done, now we have to convert it back to ounces and pounds. So divide 23 by 16, then you know how many pounds, then multiply the decimal by 16 to figure out how many ounces. Or subtract 16 from 23.4, and that's one pound, and the remaining numbers are ounces. Which makes 1 lb 7.4 ounces.
Now explain it 5 more times if the intern is mathematically inclined, or 100 more times if they're not. Or just use the metric system, which would be more like this:

Ok, we need to apply alfalfa to 60 ft
2 at the rate of 1.1 kg per 100 ft2. Since 60 is .6 of 100, we'll multiply 1.1 kg by .6. Yes, that would be .66 kg, or 660 g. Which I don't have to explain to you, because you are familiar with the metric system.
Doesn't that sound easy? Less steps, less to screw up. It's nice and simple. And that's why we're going to weigh with metric in our garden.
Ok, admittedly we will continue using ft2 instead of m2 for area, Fahrenheit instead of Celsius for temperature, and 5 gallon buckets instead of liters or m3 for volume, but you see how it's all convenient, right? People know what you're talking about, or at least you know what you're talking about.
Incidentally, our other two scales are in English units, but it will be a matter of quick conversion to fix that. I may even write the metric units on the face of our mid-range scale...
So as I was saying up at the top, all this is to announce that we now have our full complement of scales to weigh everything that goes in or comes out of the garden. With a couple of purchases last month we added to our previous 600 g /21 oz triple-beam-balance capacity, and now have a 25 lb/ 11 kg medium scale and a 600 lb / 270 kg BIG scale.
Since I think I've beaten the metric topic to death by now I'll say a little about our mid-range scale. Mostly good for all the stuff that isn't itty-bitty, like seeds, and isn't huge, like corn stalks, compost, and luggage. The mid-range scale, then, is actually very helpful in day-to-day harvesting, and we were really missing it last season, especially (as noted in the aforementioned potato post) when weighing potatoes out 1 lb 5 oz at a time. This one is bland, but high enough quality to be reliable. As you can see, the brand is Pelouze, which seems to be owned by Rubbermaid, for what that's worth. It was about $60 with shipping and all.

And for the grand finale, our new (very old) Fairbanks scale. At the Golden Rule garden I got hooked on huge platform scales that weigh a ton, both figuratively (because they're mostly cast-iron) and literally (since some of them have a 2000 lb capacity). Neat, huh? Apparently they are frequently found at farm auctions, where you can buy them for $5 and up. I wasn't in the know on that point till the past few weeks, and the $60 one posted on Craigslist was pretty enticing. Especially because all the other ones on Craigslist were $100-300. The greatest things about this kind of scale are that 1) they are virtually indestructible, 2) they have a large surface (~18"x 24") upon which to pile that which you wish to weigh, and 3) they can weigh incredibly heavy loads very accurately. You really can't beat that combo.

The scale is based on the design of Thadeus Fairbanks, who patented it waaaay back in 1830. They have a great history written up on the company's website. Ours dates back to the early 1900's. I'm sure it has seen a long, dull life, and we can't promise it much excitement, but we'll at least keep it indoors where it won't rust more than it already has.

My photos don't do it justice, but they give a good impression of the beast. At left is the full body shot, featuring cast-iron frame and wheels, wooden pillar and, gallows? I don't know what you'd call that thing. Below is a photo of the "user interface", which is brass. It goes up to 50 lb, then you can add extra weights (those disks off left) to the dangling fixture (on the right) to increase to capacity. We talked a little about going digital, but figured it was much better to steer clear of the electronics. They may be faster and easier not to botch up, but they also have shorter lives (I doubt any of the digital stuff I'm using now will still function in 20 years, let alone 100). So we've got it made! At least until we need to weight something under .05 grams or over 600 pounds...


  1. Hey, funny man. Just replied to your comment. Seb and I are moving to San Juan Island at the end of the week! (May this be the final move.) We're renting a small funky place on 3 acres shaded by trees. Crop ideas?

  2. Dan, that scale is everything you said and more. So it weighs stuff up to 600 lb? Can't wait to see it!