I'm not a physics whiz, but if I were left to my own devices I would knot each rope above the wood beam and run a big screw through the knot to keep it in. If I were actually using this in my home I would sacrifice a little style to knot under the wood beam. Good luck!

If it were me, I would use several lenghts of piano wire, secured at the top, running parallel with the lamp cords and secured to eye hooks to take the weight of the beam.

If I wanted to DIY this, I'd use two beams. Current would flow from one of the cables and be split to each fixture in the space between the beams. The wiring would be anchored below the top beam. Then I'd use veneer to make it look like one beam.

There's a number of ways you could do this
- make the holes that the cords run throw a bit larger than the cords themselves, put knots in the cords and pull them through the holes, unless the beam was really heavy or the holes were too big this would hold it up
- same as above, but instead of a knot glue a stopper of some sort in the right spot on each cord and jam it inside the hole
- don't use a solid beam, use two long pieces and there are many ways to handle this

I don't know how they did it, but after you drill the holes and run the cords through, maybe squirt in some gorilla glue? That stuff can hold ANYTHING in place. Seriously.

Those are candleholders, not lightbulbs. It's probably just rope knotted at the top and bottom of the beam since there's no need to worry about current traveling through it.

Yeah, these are candle holders, but the wiring ideas fuel another whole wave of richer ideas (at least for me).

The holes could be counter sunk so you don't see the knot under the beam.

make sure the beam isn't too heavy, but you would really only need to secure on the two ends and let the center wires flow freely... "knotting" each would lead to unevenness.

you'd never knot lamp cords, but a simple collar or stopper would suffice -- even a hefty cable-tie cinched around the cord. as mentioned above, counter-sinking the two holes would be a nice touch.

alternately, you could position on a horizontal surface just-right and fill the two end holes (with wires inserted and positioned) with epoxy, but in this application, a physical stopper would be better than an adhesive one.

if i'm not mistaken, ikea might still have these "bulb on a wire" style lights. these, a drill press (or drill and a super-steady hand) and a piece of wood and you're good to go.

you could also use thin aircraft cable (braided metal cable) on the two ends to run alongside the lamp cords for super-stability/strength (safer than relying on the cords to carry the weight).

If it were me, I wouldn't use a solid beam, but one that was hollowed out in the middle, like a bowl, and then would only have to drill holes through a narrower depth. I'd then have a smaller beam of wood that fits inside the hollowed-out bit, with holes also drilled through, to feed the rope through and rope knot under. Then the ropes go through the larger, hollowed-out beam, and you can secure the small bit inside the large bit in whatever is your preferred, messy, nobody-will-see-the-top manner.

... and up top, I'd use a massive silver hoop (or a very narrow bar), and each rope would be twice as long as hoop-to-candle, and I'd double it over & feed it through itself, so there would be no knots visible anywhere. :) It also looks like most of those ropes aren't bearing the load, so you may only need a few knots (or supports) to make it work.

I don't know what they used for cable to suspend the candle holders, but you can buy rubber O-rings at hardware stores and box stores (Home Depot) which could be snugged around the cords (and secured with glue if necessary) instead of knots. If the drilled holes were tight to the cord, and possibly counter-sunk a bit, these would be very tidy and near invisible.

I can't see committing to candlelight over the dining table with no possibility of electric light. But if you're going to do this, you should attach it to the ceiling at multiple points. If you hang it all from one central point, the whole thing is going to be rotating out of sync with the table, and your guests will have to crouch and slink to get away.

Also, I know that photo is for display in a catalog that doesn't want a lot of dead space in its images, but that thing is hung too low. The taller diners would be staring directly into the flames. The usual suggestion is that the bottom of a chandelier should be 36 inches from the top of the table.

Like Snowlet said - the knots are held in place, counter-sunk inside the beam.

Drill through the beam with a smaller drill bit all the way through to string the rope through.
Then use a slightly bigger bit and drill about 1/3 of the way through on the bottom. Knot the rope and it will hide inside the beam.

I suspect that they will post the directions on how to DIY it eventually - like their previous whirly chandelier here: http://blog.cb2.com/home/2010/7/1/whirly-chandelier-how-to.html/ ; maybe just keep checking their site to see when they do?

The Orbs are candle holders.
http://www.amazon.com/Plant-Terrarium-Hanging-Candle-Holder/dp/B005TM0SZQ/ref=sr_1_2?s=home-garden&ie=UTF8&qid=1337207966&sr=1-2

As for the beam if you drilled a hole through the wood put glue in the hole and fed the wire through it would probably hold after it hardened but I'm no contractor so don't take my word for it.

Guess who asked CB2 on their facebook page for the tutorial, and they're "looking into it"!!

Hope we get an answer soon! I'd love to put this over my kitchen island (but with rooster bulbs instead of tea lights.)