QUESTIONS AND More Questions... II
Moderator: Marilyn HS Light
10/12/2005

QUESTION #1

REUSE OF POTTING MIX - Jade asked about potting mix and if certain kinds like Aussie Gold TM can be safely reused. How can this be without chancing pathogen transfer? Are there any potting mediums except fired clay pellets that can be sterilized and reused???
According to the information given on the web site, Aussie Gold TM is made from "fresh water Diatomite imported from Australia, the finest coir fiber imported from Asia, horticultural charcoal and perlite, and some "secret" ingredients." button I have never used the product so cannot comment except on potential for reuse. As far as I am aware, only inorganic materials like clay pellets, perlite and diatomite can be sterilized at a high enough temperature to destroy the most persistent viruses. Organic materials can be especially challenging to sterilize adequately. I suggest recycling any used potting media into the garden compost.

DISCUSSION TIME FOR Question #!
Has anyone experience with the product? I have not seen it in Canada so far.

Jade_in_GR
I was given a bag of Aussie Gold TM to experiment with. I am using it against my usual medium using plant divisions. Best I can do for fair comparison. It would be easy to separate the diatomite out for reuse. If I sterilized the separated diatomite do you think there would be a problem? I would then remix it into similar mixture.

John in Arcadia CA
I have never used it. But I agree, Marilyn. Reusing anything not sterilized is too risky. The diatomite could be sterilized but is it really worth the effort to heat it high enough? I don't think so.

Ed_in_Sat
There is another risk to reuse: any sphagnum or peat content is going to hang on to a high load of mineral salts. Heating will just imbed the salts. I think one would spend the value of the mix leaching sufficiently to reuse.

MarilyninOttawa
Ditto for charcoal.

Ed_in_Sat
Absolutely! Charcoal is added for the express purpose of trapping the "bad guys". Once loaded through use, I know of no way to clean it. Brewers never reuse even their 'polishing' charcoal.

Jade_in_GR
I would be hesitant to heat the charcoal at high heat on the chance it might ignite. I also agree with Ed about why it is used in a mix in the first place.

Ed_in_Sat
Great growing rarely comes in a bag - any bag.

John in Arcadia CA
Wouldn't it be a lot of work to separate it Jade?

MarilyninOttawa
If the diatomite is similar in particle size to what I have seen, then it could be separated - I agree. It would have to be soaked with hot water and rinsed several times before heating further.

Jade_in_GR
I don't know how they can make the claim of reusable. I asked this question specifically to get all your expert ideas about it. Rather poor claim and nothing on bag says anything about resterilization.

Ed_in_Sat
If diatomaceous product could be regenerated I feel pretty sure the swimming pool people would have found a way to do so. Diatoms are of value for the spaces in their structure.

Jade_in_GR
John, diatomite would be pretty easy to sieve out of used mix. The pieces are significantly larger than rest of ingredients. In fact, hard to put in pot because of the discrepancy in both texture and size. It may be a good medium-I will give you feedback on that in a few months but --but definitely not the panacea that the advertisement claims.

MarilyninOttawa
We look forward to having feedback, Jade. I feel that it is best to use fresh ingredients for potting orchids. As I said, the used material works quite well in the garden. That being said, if you have any problems with serious plant diseases/pests, pour boiling water over the old stuff before garden use.

[Link to an OrchidSafari Archive discussion about diatomite: http://users.silcon.com/~orwell/01222003a.html - KB]

QUESTION #2

COIR - Jade asks another question about potting material. She asks: "What is the feedback on using loose coir ? I have used CHC (coconut husk chips) and have been happy with it for phrags especially but have never used loose coir."

Coconut husk contains both coarse fiber (coir) and granular material packed between the fibers (coir pith). CHC is available as loose or compressed in various sized chunks, and as compressed blocks of granular material often marketed as cocopeat. button The product is inexpensive and a good substitute for bark chips or peat moss. I use medium chips blended with sphagnum moss as a phrag mix with excellent results. I have found Oncidium alliance grow happily with various CHC products. I usually soak chips overnight or put a tray of chips out in the rain which hydrates them nicely. An excellent review of the subject can be found at button

DISCUSSION - COIR Are there any comments or suggestions about this now popular and readily available potting material?

Ed_in_Sat
Lets be sure we are all talking about the same thing. What is called 'coir' in a commercial operation is milled coconut product that is compressed under great pressure. It comes in blocks of about 1 cubic foot and expands hugely when covered with water. The expansion is on the order of 5X to 7X. The material looks rather like coffee grounds and is about that color. For us, it grows seedlings well in very small containers called blow mold 38's: 38 cells to a standard tray. It dries out very quickly. As an additive in larger pots, it tends to go out the drain holes or make sludge in the pot bottoms.

John in Arcadia CA
I am using CHC in a mix of CHC, diatomite and perlite. I have potted Anguolas, Paphs, and a Phal it it. No result yet but looks promising.

MarilyninOttawa
Has anyone not tried coconut husk potting material?

Ed_in_Sat
Please note: CHC and coir are totally different products.

Jade_in_GR
My question was specific to the loose coir. I am as happy with chips exactly as you are but suddenly am finding it hard to find a supplier in area. :-(((

John in Arcadia CA
I recently found a brick of compressed "stuff" that looks like very small CHC with some coir in it. I have mixed it with a terrestrial mix that I bought and diatomite to make a mix for some seedling Paphs. They seem to like it a great deal - so far!!!

Ed_in_Sat
Coir would make a good amendment to many potting soils. It is friendly to production Paphs and a good seed starter. Again: commercial coir is a granular material that resembles coffee grounds. The largest source is in St. Louis. I can get specifics if anyone needs them.

MarilyninOttawa
I agree Ed. At the earlier web site mentioned button , they clearly differentiate between coir fiber and the granular material. For clarity's sake, lets talk coir granules (which I buy in compressed bricks) and chopped husk (which can be purchased in compressed bales/bricks of various size pieces or loose).

Ed_in_Sat
Sounds like a good plan.

Jade_in_GR
Yes Ed you are correct. I am asking about the loose long fibers that when separated can be used to weave mats etc. I have seen it sold. It would be a bit similar to osmunda in what it looks like but lighter brown. As noted in the website it is often sprayed with latex and used for mattresses. Also, I have some that has be made for the hydroponic market. That comes in assorted sizes of cubes. I am presently give it a try as a mount. Local hydroponic dealer was throwing out a bunch (new) and I releived him of the burden. I think they might be good for mounting .

John in Arcadia CA
Does this stuff need to be soaked and rinsed and soaked again like the CHC does?

Steve_in_the_Adirondacks
I bet it can be rinsed in minutes since it doesn't have the spaces that trap salts and salty rinse water.

MarilyninOttawa
I find that Oncidium alliance like it (the granular material) particularly. To avoid losing material out the bottom of the pot, I place a sheet of shade cloth. This does not interfere with drainage but keeps the material in place. I now prefer the granules and the chips in place of bark. We have no problem with supply as yet. There are several distributers locally and it can be found in many garden centers.

Jade_in_GR
OK folks we are talking about 3 different products and I know 2 work well for orchids. Heck, in Sri Lanka folks take half a coconut husk and stick a Vanda in it and tie it to a tree and voila it grows.

Ed_in_Sat
It is confusing, Jade. I, too, know the coir mats and sandal soles. Before ordering from a horticultural supply house, either understand the examples I emphasize or ask for a sample of the material you will receive. Coconut product is, generally, expensive to ship and rather worthless if you have a big box full of the wrong stuff.

John in Arcadia CA
Around here we are told to soak CHC for 24 hours then drain and do it again and maybe a third time - all to get rid of salt in the product. What a chore!!!!

Ed_in_Sat
Let's put it this way, John: coconuts form within sight of the sea. They are commonly moved to market in rafts over salt or brackish water. I rinse the heck out of what we use, adding just a little detergent to insure full wetting.

Rickwo_Melbourne_Aust
Cocopeat is becoming very popular with Aussie growers. A compressed bloc is $5.00A (expands to 60-70 litres) against a bag of good quality bark $25.00. Ausssie natives seem to like it as it retains more moisture than bark. It also seems a good substitute for sphagnum for Masdevallias.

MarilyninOttawa
I always wet potting material before use and coconut products are no exception. The fiber does not absorb water but the chunks, which are many fibers with spongy material (coir pith) between, does hold more water. We can buy fiber mats to line hanging baskets and this would work for orchids also.

Jade_in_GR
To get back to my question, does anyone have experience using the long fiber stuff? Would one use it like osmunda?

Ed_in_Sat
I hope not!!!!!

MarilyninOttawa
Why, Ed?

Steve_in_the_Adirondacks
I would think you would pack it no where near as tight as Osmunda should be packed.

Jade_in_GR
The mats are made out of the coir long fibers. Guess no one here has seen it used or tried it. I will keep searching and give you all feedback when I get the answer. Re: soaking and rinsing. I use quite a bit of the ch chunks. I soak them for an hour, pour off the water, and mix with sponge rock and charcoal and pot away. Phrags grow like day lilies. No salt damage. I have a good nose and chc don't smell like the sea.

Ed_in_Sat
Sorry - I should explain. Years ago, before bark, osmunda was the potting material of choice - often the only choice. We all had 'potting sticks' which were about the diameter of a broom stick, 18" long, with a chisel end. Most people slipped a motorcycle hand grip over the other end when they got over their first set of blisters. The plant was positioned in the pot, then osmunda was pounded tightly around it. Tight as in I have seen lots of clay pots split. For whatever reason, it grew great orchids and crippled all of us who practiced the art. It was almost never fertilized. It had modest nutrients in it and they sufficed.

Jade_in_GR
I have one of those potting stick but no motorcycle hand grip. I used the top of a hickory handle

MarilyninOttawa
I have a memory of using coconut husks (pieces of entire husk that we had pried off garden coconuts before using the nut). I planted all sorts of orchids on these husk pieces but they never grew orchids quite as well as broken 'crock'/fired clay pieces. I feel that husk can sometimes hold too much water and this is not an ideal for some orchids.

John in Arcadia CA
That is probably why the perlite was added to the mixes I have seen written about. Diatomite also draws some water out of the CHC.

[Link to a previous discusion about coir (coco granules) from the OrchidSafari Archives http://www.geocities.com/brassia.geo/8162000.html - KB]

QUESTION #3

MEDIA FOR HOME FLASKING - Kathy requested some information on media selection advice for home flaskers. If we want to try raising orchids from seeds, which medium formulation is best? Whereas in times past, it was challenging to obtain small quantities of good prepared media, today there are many proven formulations available for purchase on-line and in small quantities, at an amazingly low price. For the home flasker, it is simply not worth investing in components except for such items as bananas, coconuts or pineapple juice. Even then, standardized powdered banana, coconut water and pineapple juice are now part of many formulations or can be purchased separately. Some suppliers list media for both tropical and terrestrial orchids whereas others deal only with tropicals or with a particular orchid type like Phalaenopsis. For example, at the PhytoTechnology Labs site, button we can find everything from orchid media suited to a range of taxa, to equipment, kits and useful books.

John in Arcadia CA
I am going to ask my seed germinator if I can buy a flask from him. That way I won't have to mix up anything nor sterilize it!!

Ed_in_Sat
Fruits, fruit juices and such bought at the grocery store frequently have an elevated sodium content, preservatives, etc. It would be risky, though not totally defeating, to put these into flasking media. Be especially cautious of tomato juice.

Jade_in_GR
Is that canned pineapple juice? I have always been mystified about using pineapple since it seems to be rather like a tenderizer when raw.

MarilyninOttawa
I have often wondered about so-called defined media being mixed with undefined fresh banana pulp, fresh filtered juice such as coconut water. All the effort to prepare an exact recipe seems to fly out the window. Fresh fruits contain a wide range and quite variable levels of 'growth factors' including some vitamins. Why a certain fruit additive works is still much of a mystery although progress is being made. Jade, once pineapple juice is cooked/sterilized, the enzymes are inactivated.

Jade_in_GR
Exactly my conclusion regarding the pineapple juice. Sounds like it is used more for its fructose content.

Ed_in_Sat
There are some excellent cold sterilization packs available. We use one that has the upper and lower units prepacked with a filter between. Just hook up a vacuum hose and away we go. This is also great for sterilizing weak fertilizer solutions for addition to a flask that is just that bit short of coming out.

MarilyninOttawa
Good point Ed. If it were not for heat being needed to melt the agar, then the rest could be filter sterilized. I agree.

Ed_in_Sat
Pour the medium in a blender after half the cooking time. It will work better and you never get that rubber film on top.

MarilyninOttawa
Rubber film?

Ed_in_Sat
Yep, the one that is impermeable to tiny root tips.

MarilyninOttawa
Some basic questions about flasking media:

1 - Does it contain a gelling agent and why? Some formulations do not contain agar but there is often an alternative listing of a similar formulation with added gelling agent. Gelled media provide a firm surface on which to place seeds. Liquid media are preferred for tissue culture and have proven useful for certain kinds of seeds. An inert physical support like glass wool can be used to hold tissue just at the liquid surface. Always check the description to be certain you are ordering the formulation you require.

2 - Does it contain charcoal and why? Powdered, activated charcoal has proven to be a useful ingredient in some formulations where it adsorbs substances detrimental to continued plant development. Depending upon the species sown, charcoal can positively or negatively impact protocorm and seedling growth but most common species germinate well on charcoal-containing media. When in doubt, try two similar media with and without added charcoal.

Ed_in_Sat
We find charcoal is essential in working with Phal alliance flasks. Phals tend to give off toxins through the roots. Frequent replating onto a charcoal-fortified medium will offset this to a very large extent. We often run a single Phal cross through 4 - 8 replates.

MarilyninOttawa
Phals, especially stem props, can produce a lot of polyphenolics, which darken an otherwise translucent medium. The charcoal is thought to adsorb such material and it works!

MarilyninOttawa
3 - Can I use the medium at half strength? Powdered media are designed to provide the desired final concentration of mineral salts, sugar, agar and other ingredients. When added to the recommended quantity of water and dissolved with heating, the mixture will arrive at a specified pH value. Adding more than the recommended quantity of water will not only dilute the ingredients further but may also affect the final pH.

If you look at various media formulations, you will find that often one contains half of the ingredients in the other, at least it appears that way until you compare all ingredients. Certain ones are kept at the same concentration in both formulations, eg, agar or sugar.

4 - I want to germinate seeds of an unusual species. Which medium should I choose? There are some 25,000 orchid species. Flasking experience is limited to a very few of them. There is far more experience with the popular genera so much can be learned by reading flasking manuals and from consulting with experienced individuals. There may be some knowledgeable people locally. Many tropical orchids will germinate well on the same flasking medium and only a very few require special formulations. I use both P658 and P723 (PhytoTechnology), both of which contain charcoal and agar. When in doubt, I try some of each.

Temperate terrestrial orchids are the more challenging because they not only require different formulations but they also have dormancy issues. You can read about Cypripedium flasking challenges and related issues at button

5 - I wish to raise hybrid orchids from seeds. What points should I keep in mind? Ideally, a beginner should learn techniques using easy-to-germinate species seed such as Epidendrum. Whereas tropical species orchids present relatively few challenges to raise from seeds, hybrids can be quite a different matter. For example, seeds may contain few to no embryos. When we hybridize, we may mix chromosomes such that only a few fertile embryos are formed. The fruit may be filled with 'seeds' but when we take a close look, most of the seed coats are mere empty husks. The problem then is not with choice of flasking medium but rather, how much 'seed' should be sown to get some seedlings.

Ed_in_Sat
I think when you find a medium that works for you, you will use it for everything. At least, we do. We do flasks 14 at a time and it would drive us nuts to keep track of ones and twos.

MarilyninOttawa
It really depends what is being done. I work with epiphytes and terrestrials, temperate and tropical, and am continually trying to germinate species about which there is little known. Therefore, my strategy is to use several different formulations.

Ed_in_Sat
Make as much of your equipment as you can. You get better stuff at far less cost. I have pix of some if you want them now or later.

MarilyninOttawa
Please show us what you have.

Ed_in_Sat
First of all, we use 500 ml French bottles with #8 1/2 rubber stoppers. Period. We use prepared media from Sigma and don't monkey with it. Our 'autoclave' looks like a chili cooker from a dorm room: picture

MarilyninOttawa
Looks like my mom's old canner! Works for me too.

Ed_in_Sat
Same one. The only change we made to a standard pressure canner is we put the wobble valve from a Presto cook pot in one threaded hole so we wouldn't have to pay much attention to keep 15 pounds of pressure. This one is ancient. Don't forget to keep a sliver of sealing wax at hand to rub the seal edges on lip and pot. Makes a good seal with much less pressure on the lugs. We use Potassium softened water in ours - less corrosive than distilled.

MarilyninOttawa
Good tip! I use tap water and have not had problems with corrosion even after some 60 years. Had to replace the gasket however.

Ed_in_Sat
We store prepared flasks in a cool dark place. They keep for a long time. When ready for use, we run them through the wash tub: picture

MarilyninOttawa
I upend stored bottles in bleach solution for a few minutes before opening which reduces chance of contamination.

Ed_in_Sat
The French bottle in the corner will hold our flasking tools: 2 pr of tweezers sold to get stuff out of a garbage disposer and a couple of probes we make out of 1/4" stainless welding rods. The bucket you see is for used rags and other trash. We use lots of rags soaked in a 12.5% Clorox solution. Very scientifically cut from old bed sheets and folded twice.

MarilyninOttawa
Didn't know they sold tweezers for that purpose! makes sense.

Ed_in_Sat
Get 'em at the hardware store (not Lowe's or Home Depot). I'll get some more pix and we'll have a separate session on home made flasking gear.

MarilyninOttawa
Thank you Ed for sharing your experience and ingenuity. I agree that this deserves a whole session and look forward to it.

-end

Prechat Handout

QUESTIONS AND More Questions... II

Marilyn HS Light

1 - REUSE OF POTTING MIX
Jade asked about potting mix and if certain kinds like Aussie Gold TM can be safely reused. How can this be without chancing pathogen transfer? Are there any potting mediums except fired clay pellets that can be sterilized and reused???

According to the information given on the web site, Aussie Gold TM is made from "fresh water Diatomite imported from Australia, the finest coir fiber imported from Asia, horticultural charcoal and perlite, and some "secret" ingredients." http://www.aussie-gold.com/

I have never used the product so cannot comment except on potential for reuse. As far as I am aware, only inorganic materials like clay pellets, perlite and diatomite can be sterilized at a high enough temperature to destroy the most persistent viruses. Organic materials can be especially challenging to sterilize adequately. I suggest recycling any used potting media into the garden compost.

2 - COIR
Jade asks another question about potting stuff. What is the feedback on using loose coir ? I have used CHC (coconut husk chips) and have been happy with it for phrags especially but have never used loose coir.

Coconut husk contains both coarse fiber (coir) and granular material packed between the fibers (coir pith). CHC is available as loose or compressed in various sized chunks, and as compressed blocks of granular material often marketed as cocopeat. http://en.wikipedia.org/wiki/Coir
The product is inexpensive and a good substitute for bark chips or peat moss. I use medium chips blended with sphagnum moss as a phrag mix with excellent results. I have found Oncidium alliance grow happily with various CHC products. I usually soak chips overnight or put a tray of chips out in the rain which hydrates them nicely.

An excellent review of the subject can be found at http://www.ladyslipper.com/cocofaq.htm

3 - MEDIA FOR HOME FLASKING
Kathy requested some information on media selection advice for home flaskers. If we want to try raising orchids from seeds, which medium formulation is best?

Whereas in times past, it was challenging to obtain small quantities of good prepared media, today there are many proven formulations available for purchase on-line and in small quantities, at an amazingly low price. For the home flasker, it is simply not worth investing in components except for such items as bananas, coconuts or pineapple juice. Even then, standardized powdered banana, coconut water and pineapple juice are now part of many formulations or can be purchased separately. Some suppliers list media for both tropical and terrestrial orchids whereas others deal only with tropicals or with a particular orchid type like Phalaenopsis. For example, at the PhytoTechnology Labs site, http://www.phytotechlab.com we can find everything from orchid media suited to a range of taxa, to equipment, kits and useful books.

SOME BASIC QUESTIONS ABOUT FLASKING MEDIA:

1 - Does it contain a gelling agent and why?

Some formulations do not contain agar but there is often an alternative listing of a similar formulation with added gelling agent. Gelled media provide a firm surface on which to place seeds. Liquid media are preferred for tissue culture and have proven useful for certain kinds of seeds. An inert physical support like glass wool can be used to hold tissue just at the liquid surface. Always check the description to be certain you are ordering the formulation you require.

2 - Does it contain charcoal and why?

Powdered, activated charcoal has proven to be a useful ingredient in some formulations where it adsorbs substances detrimental to continued plant development. Depending upon the species sown, charcoal can positively or negatively impact protocorm and seedling growth but most common species germinate well on charcoal-containing media. When in doubt, try two similar media with and without added charcoal.

3 - Can I use the medium at half strength?

Powdered media are designed to provide the desired final concentration of mineral salts, sugar, agar and other ingredients. When added to the recommended quantity of water and dissolved with heating, the mixture will arrive at a specified pH value. Adding more than the recommended quantity of water will not only dilute the ingredients but may also affect the final pH.

4 - I want to germinate seeds of an unusual species. Which medium should I choose?

There are some 25,000 orchid species. Flasking experience is limited to a very few of them. There is far more experience with the popular genera so much can be learned by reading flasking manuals and from consulting with experienced individuals. There may be some knowledgeable people locally. Many tropical orchids will germinate well on the same flasking medium and only a very few require special formulations. I use both P658 and P723 (PhytoTechnology), both of which contain charcoal and agar. When in doubt, I try some of each. Temperate terrestrial orchids are the more challenging because they not only require different formulations but they also have dormancy issues. You can read about Cypripedium flasking challenges and related issues at http://www.cypripedium.de/forum/

5 - I wish to raise hybrid orchids from seeds. What points should I keep in mind?

Ideally, a beginner should learn techniques using easy-to-germinate species seed such as Epidendrum. Whereas tropical species orchids present relatively few challenges to raise from seeds, hybrids can be quite a different matter. For example, seeds may contain few to no embryos. When we hybridize, we may mix chromosomes such that only a few fertile embryos are formed. The fruit may be filled with 'seeds' but when we take a close look, most of the seed coats are mere empty husks. The problem then is not with choice of flasking medium but rather, how much 'seed' should be sown to get some seedlings.

Additional references:

A detailed list of media and related material can be found at the Orchid Seedbank site http://members.cox.net/lmlauman/osp/html/mcsg_database.html

There are several manuals that outline flasking technique including: http://www.kaysgreisenspecialties.com/orchid_manual_info.htm

Additional sources of information, current as of 10/2/05. No attempt will be made to keep these links current. Please Google it for more information. -[k barrett]

1) http://www.orchidmall.com - 1st resource I go to for all things orchid. Orchid Wire (http://www.orchidwire.com) is a second source, but you can't beat the Mall.

2) http://www.phytotechlab.com - Phytotech labs, source for media and flasks and other stuff.

3) http://www.lulu.com/content/39163 - a link to a book called 'Orchids from Seed for Pennies' by CD Molton. I have no idea if its any good, I just found it in a search.

4) http://www.appliedsciencecenter.com/ - Applied Science Center has pod harvesting dates. I have no idea as to their accuracy, I just found it in a search.

5) http://www.kaysgreisenspecialties.com/orchid_manual_info.htm - link to another book called Commercial Propagation of Orchids in Tissue Culture: Seed Flasking Methods by Kay S. Greisen. Again I have no idea if its any good.

6) http://www.users.bigpond.com/gmcorbin/bos/Flasking.html - From the Brisbane Orchid Society, a 'how to' on flasking

7) http://www.tissuequickplantlabs.com/tqplpageonefinalnf.htm - For those in the UK here's Tissue Quick Labs webpage. Alan (I'm blanking on his last name) usually hangs out online and is very quick to answer my plant biology questions, especially when I'm wrong, LOL!!

8) http://www.orchidlady.com/orchidgarden/2001-07/ - Linda Fortner (The Orchid Lady!) discussion on to flask or not to flask, that is the question.

9) http://www.orchidspng.com/seed_flasking1.html - from Wolfgang H. Bandisch's Papua New Guinea webpage, again a great 'how to' page.

10) http://www.psfdev.com/los/flasking/ - From the Lincoln Orchid Society, another 'how-to' page

11) http://members.cox.net/ahicks51/osp/ - Aaron Hicks' Orchid Seedbank Project. Should have links to his 'Asymbiotic Technique' book, but I think its out of print (???)

And - at the risk of being accused of blatant self promotion: From the OrchidSafari archives:

12) http://www.geocities.com/~marylois/archiv18.html - The Trembling Toothpick: Basic Hybridizing by Ed Wright

13) http://www.geocities.com/~marylois/archiv23.html - Stem Props by Ed Wright

Which reminded me of one I missed from the OrchidSafari Archives: Boys in the Hood http://www.geocities.com/~marylois/arch207.html