Biomass-burning camp stove, pt. 1

For some time, I’ve been thinking about making a lightweight portable stove that burns biomass instead of fossil fuels. Search the Web, and you’ll turn up lots of plans for such stoves — tin can rocket stoves, Canadian candle stoves, etc. But most of the plans I looked at seemed overly complicated and not particularly elegant. Then I stumbled on a video titled “How To Make a Wood Gasifier Stove”: it showed how to make a stove that was simple, even elegant. So tonight I made one.

The basic principle for the “wood gasifier stove” is the same as for a rocket stove: the solid biomass fuel (wood) burns at the bottom of the stove, with another combustion area higher up where rising gases are enabled to burn further. This is supposed to extract more heat from the fuel, and additionally the more complete combustion should result in less crud going into the air and into your lungs. However, where the rocket stove has been tested for greater efficiency by scientists, I know of no such studies for this design; we’ll just take it on faith that this design is probably more efficient than an open fire.

The biomass-burning stove
The biomass-burning stove with a fire in it

The stove requires two “tin” cans, one larger than the other: I got a 15 oz. can of pears, and a 29 oz. can of peaches. The smaller can, nested inside the larger can, is where you build the fire. Ventilation holes at the bottom of the larger, outer, can line up with ventilation holes at the bottom of the smaller, inner, can. The smaller can also has a row of ventilation holes near the top; this is where additional air is injected so to make rising gases can burn. If you look carefully at this photo of the stove I made, you can see the upper ventilation holes, with jets of flame coming out where the injected air is igniting rising gases.

Upper ventilation holes in the stove
Upper ventilation holes in the lit stove

I completed the basic stove in about an hour (including the time it took to eat the pears). The stove is reasonably practical, particularly for car campers or ordinary backpackers (i.e., not those crazy ultralight backpackers). And the stove is environmentally responsible: it’s made with recyclable materials, and it burns biomass instead of fossil fuels like white gas, butane, or propane. Plus, since it’s homemade, it doesn’t feed consumer consumption; and consumerism is a major contributing cause to the pending global environmental disaster.

I still have to make a potholder, to keep the cooking pot a couple of inches above the flames, where the greatest heat should be — but I have to wait until I eat another can of pears. Once I get the potholder made, I’ll post a photo showing something cooking on the stove (and I’ll add a sketch showing how to make one).

Goat finale

Today, the owner of the goats came to pick them up. He and his helper backed the goat trailer up to where the goats were penned in. While the humans were dismantling the electric fence, they let the goats munch on a few last weeds. The herd dog stayed in the goat trailer, waiting until he might be needed.

Goats getting ready to go home. Photo courtesy Carol Steinfeld.

But the goats, being goats, wanted more to eat. The electricity had been turned off in the fence, and the goats found a small opening they could sneak out of. Carol looked up from her laptop and suddenly saw a couple of goats in the small cemetery parking lot. We went out to see what we could do, but the goats paid no attention to us. Then more goats came out. Pretty soon, all the goats were out. Carol called the cemetery superintendent so the superintendent could call the goatherds on their cell phones. By now, the goats were moving in a bunch across the cemetery, cropping grass as they went.

Soon one of their humans showed up, and he got the herd dog. Between the two of them, the human and the dog got the goats moving back towards the trailer. The goats would try to break away — all that lovely grass, just waiting for them! — but the dog would run quick as lightning and head them off, with his human partner cutting off any chance of retreat. At last the goats broke into a trot and ran towards the trailer.

Goats on the loose
Goats in retreat. Photo courtesy Carol Steinfeld.
Goats in retreat
Goats breaking into a trot. Photo courtesy Carol Steinfeld.
Goats heading back to trailer
Goats heading back to the trailer. Photo courtesy Carol Steinfeld.

Carol watched the action from inside the cemetery, while I and one of the cemetery gardeners stood in the parking lot, both to try to keep the goats from escaping into the streets of San Mateo, and to make sure any visitors who drove in didn’t run over a goat. We weren’t really needed, though; the herd dog and his human quickly had the goats under control.

Soon enough, all the goats were back in a fenced-in area, ready to be loaded in their trailer. Carol and I went back inside, and opened up our laptops. It didn’t last long, but the goats’ breakout provided a dramatic finale to their stay at the cemetery.

Wasp

This evening, I went out to look at the paper wasp nest that is well-hidden in the native plants garden at the church. I’ve learned that in the hour before sunset, the founder wasp rests herself on the nest, between the nest and its supporting twig, just below the petiole. And that’s exactly where she was when I got out there.

My camera is a good tool for getting a close look at her without getting too close; I have a healthy respect of wasps and have no desire to provoke her into stinging me. Looking at the photos I took of her, it looks like she has added some cells to the nest. The light began fading rapidly while I was taking photos, and it wasn’t long before the camera would no longer focus on the nest; as a result, I didn’t get any photos looking into the ends of the cells, so I’m not sure whether the cells contain any eggs or larvae.

Goats

St. John’s Cemetery, where we live, owns a strip of land between the actual cemetery and an adjacent residential neighborhood. This strip of land, while attractive, has gotten overgrown with undesirable plants like Russian thistle and poison oak. As an environmentally friendly way to control these undesirable plants, Kathy, the cemetery director, brought in Green Goat Landscapers.

The goats arrived this afternoon, and I went out to look at them this evening. They are safely installed behind a temporary electric fence — the fence not only keeps the goats in, it also keeps any roaming mountains lions out (and yes, mountain lions have been seen in the cemetery).

I found it very satisfying to stand and watch the goats. Perhaps I had distant ancestors from Eurasia who herded animals, and I still have some ancestral memory of that. More likely, it’s just that herd animals and humans spent a lot of time with each other, and while we humans domesticated goats, the goats for their part also domesticated us.

Eventually computers will domesticate us in different ways, but at the moment we humans are still closer to goats than to computers. I stood watching the goats eat the thistles. They didn’t seem to mind the prickles on the thistles; their facial expressions showed no signs of pain; only contentment.

I stood watching the goats for quite a while, and had a brief fantasy about being a goatherd. But goatherding is even less remunerative than being a children and youth minister, so I went indoors to check email.

Polistes

Nancy saw a paper wasp beginning to build a nest. We watched it for a few minutes. The nest is still small, with perhaps 16 cells. We saw one adult, who sat quite still on the nest for more than a minute at a time; then she (presumably it was a female) would fly off and return after a minute or so. I wondered if she were working on building the nest; but she was working on the underside of the nest, and the nest was located where we couldn’t see the underside without disturbing her, we could not confirm my conjecture. I did, however, manage to take two photos with Carol’s phone:

I feel fairly confident assigning this individual to genus Polistes, a genus which includes dozens of species of paper wasps. The online “Bug Guide” of the University of Iowa’s Department of Entomology says of genus Polistes: “Predatory on other insects (predominantly caterpillars) to feed larvae.” Nancy left the nest there so the wasps could serve as a biological control on voracious caterpillars and other herbivorous insects.

Odorous house ant

It’s that time of year: the Odorous House Ants (Tapinoma sessile) are sneaking indoors to get out of the rain. At least I think that’s what they are: they’re the right size and shape, and when you crush one it smells vaguely floral (some people describe the smell as being like cocnout sun tan oil). One of the ants paused on the edge of our sink long enough for me to take a photo that’s only slightly blurred:

More about Odorous House Ants from Dr. Eleanor’s Book of Common Ants, on the School of Ants Web site.

California Tortoiseshell

At about 5:30, while wandering around St. John’s Cemetery enjoying the first warm spring day, I saw a number of California Tortoiseshell butterflies flying under some live oaks. I tried to count them but they were moving too fast: at least half a dozen, probably more. They were very active, but some of them settled long enough for me to take their photo. I noticed that the edges of their wings were quite worn.

California Tortoiseshells are migratory butterflies. They hibernate in winter in the foothills of the Coast Range — St. John’s Cemetery could be considered in the foothills of the northern end of the Santa Cruz Mountains . According to Arthur M. Shapiro in Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions: “When they emerge from hibernation in late winter the males are late-afternoon territorial perchers in classic nymphaline style.” Indeed, the butterflies I saw appeared to be patrolling territories, perching in one spot and periodically circling around a small area, sometimes flying at other butterflies in nearby territories.

I went back to the house to get a camera with a better zoom, but by the time I had returned, the sun was almost below the horizon and the butterflies had gone away.

Risk Reduction Resource Kit

Alex, a friend who works at Health Initiatives for Youth (HI4Y) in San Francisco, told me about their Risk Reduction Resource Kits. These kits contain resources to help teens teens learn about sexuality and safer sex. Alex knows about the OWL comprehensive sexuality education program, and has heard me describe our youth programs, and based on that he encouraged me to put in an application for the last remaining Risk Resource Reduction Kit, and Carol and I went in to JI4Y’s offices to pick up the kit on Monday.

The whole point of the kit is that it’s supposed to be placed where teens can access it without adult supervision, to encourage them to explore the materials on their own. The kit was designed to accompany a sexuality education curriculum developed by HI4Y, but be accessible both to teens taking the curriculum and other teens. So for our congregation, it’s a prefect accompaniment to the OWL unit for gr. 10-12; for those taking OWL the kit will reinforce the curriculum; and it can also serve as an educational resource for those not taking OWL.

The Curriculum Subcommittee of our congregation met the day after I picked up the kit, and we devoted the meeting to talking about the kit. The Curriculum Subcommittee has been exploring ways to be more intentional about our congregation’s implicit curriculum, asking ourselves: How can we structure intentional learning opportunities that are not part of the explicit curriculum, the formal educational programs? We agreed that the kit is a solid addition to our implicit curriculum: Not only does it educate teens about specific sexuality topics, it provides a larger lesson that information about sexuality should be easily accessible and shared without shame or guilt.

Beyond educational theory, we also talked about how best to implement this aspect of our implicit curriculum. Alex had warned us that sometimes the kits get forgotten, and stowed in some obscure corner. So we’re going to provide orientation to the kit for key adults (youth advisors, OWL leaders, ministers, and others) to increase the chance that adults will remember to make the kit accessible. In addition, we’re also going to provide a brief orientation to the kit to teens — both to youth group members, and participants in OWL gr. 10-12 — showing them what’s in the kit, and telling them where it will be located. (When we offer OWL for gr. 7-9 next year, we’ll do another orientation.)

But the real strength of the kit is what it contains. HI4Y came up with some excellent youth-friendly resources, including comics, zines, books, and samples — I’m putting a complete list of what’s in the kit below. The materials are housed in a wheeled nylon case, like airline luggage (actually, it’s a scrapbooking case HI4Y bought from Michael’s art supply). A highlight of the kit is contraceptives samples that youth can examine: condoms of course, but also dental dams, female condoms, and lubricant; HI4Y even has some grant money left to replenish samples when they get depleted. There’s both a penis model (made of wood, not plastic!) for trying condoms, and a vulva/vagina model for trying female condoms. We were able to add one very important thing to this kit: our congregation has a ten thousand dollar bequest that we can use to put books in the hands of children and teens, so we are able to provide copies of the book “S.E.X.” by Heather Corinna that youth can take for their own.

We would not have been able to afford to put this kit together ourselves, and we are grateful to HI4Y for writing the grant and assembling the kit, and to the federal government for providing the grant money. Just in case your UU congregation can find the funding, I’m going to provide a complete list of all the resources in the kit below; at the very least, this list of resources might spark ideas for you.

The Risk Reduction Resource Kit (we added the sign at top).

Here’s what’s in the kit:

Birth control samples and examples:
Dental dam samples
Female condom samples
Female Contraceptive Model (to practice inserting female condoms)
Lubricants samples
Male condom samples
Penis model (to practice with male condoms)
IUD model
The Ring model
The Pill model
The Implant info card
Plan B info card
Birth Control Patch info card
“How Well Does Birth Control Work” info card

Home test kits:
Pregnancy test kits
HIV Home Test Kit information (actual kit is stored separately, per instructions from Health Initiatives for Youth)

Handouts and Miscellaneous:
“Pre-Exposure Prophylaxis” handout
Individual Drug Fact Cards (handouts)
Drug Fact Cards set
Chlamydia Plush Toy
HIV Plush Toy
Youth Clinic Youth Guide to San Francisco and Silicon Valley (list of local clinics that serve youth; includes 1-page summary of California law on youth’s right to treatment)
(We also added handouts from the nearest Planned Parenthood Health Center)

Publications:
“Dr. Rad’s Queer Health Show: Self Exams & Check-Ups” zine by Rad Remedy and Isabella Rotman
“You’re So Sexy When You Aren’t Transmitting STIs” comic zine by Isabella Rotman
“Not on My Watch: Bystander’s Handbook for Prevention of Sexual Violence” comic zine by Isabella Rotman
“100 Questions You’d Never Ask Your Parents” book by Elisabeth Henderson and Nancy Armstrong
“S.E.X.” book by Heather Corinna
“LGBTQ: The Survival Guide” book by Kelly Huegel Madrone
“Birth Control Top Picks” magazine by Bedsider.org

Lichen

Lichen, Parmotrema species

Several of the live oak trees in the older part of St. John’s Cemetery in San Mateo have branches on which grow bluish-gray foliose lichens with ruffled edges lined with black cilia. The thallus appears to be attached to the substrate mostly in the middle, leaving the edges curling up. On some, small round soralia could be seen (a soralium is where a lichen produces soredia, which are small bits of fungal hyphae and phtyobiont that can be released to produce a new lichen).

Lichen, Parmotrema species

After consulting Stephen Sharnoff, A Field Guide to California Lichens (Yal Univ., 2014), I’d place these lichens in the genus Parmotrema; without doing any chemical tests, I’d guess P. arnoldii Powdered Ruffle Lichen, or P. perlatum Common Powder Ruffle.