Contact juggling is one of the purest forms of technical juggling1. It is enormously satisfying, insanely difficult, pleasantly minimalist, and depressingly unimpressive to an audience who are unaware of just how hard it is to learn. A good contact juggling performance looks just like magic, where simple impossibilities are performed openly, but there is actually no trickery involved.
If practising in the privacy of your own home, all that's needed is a single ball-like object. A normal juggling beanbag would be ideal, or perhaps an orange which you don't mind bruising, but a tennis ball is too light. Contact juggling is prone more than other types not just to drops but to uncontrollable throws across the room. For this reason, the usual juggler's trick of practising in front of a bed in a room with no fragile objects is recommended, as the bed will catch the dropped balls and save you bending down.
For performance, most serious contact jugglers prefer 'crystals' - perfectly spherical, hard, colourless transparent balls, usually two or three inches in diameter. They're usually made of acetate, as this is more robust and less prone to scratches than glass. Clear balls are preferred for a number of reasons. Manipulated properly, a crystal looks like a bubble that has somehow frozen and attached itself to the hand. The lack of any colour or pattern means the audience can't see it rolling, reinforcing the illusion of floating.
The Basic Pattern
The basic pattern or trick in contact juggling is known as the butterfly. This consists of simply holding the right hand out to the right side of the body (for left-handers it would be the opposite), palm up, as though doing half a shrug. The chosen ball rests on the palm. Now waft the hand nonchalantly to the left in front of the face as though swatting a fly. Incredibly, the ball seems to stick to the surface of the hand throughout, rolling smoothly along the fingers, up over the tips as the hand becomes vertical, before coming to rest on the back of the hand as it stops, palm down, in front of the face. Now waft back. At all times the ball remains in contact with the hand, hence 'contact' juggling. There is no trick involved, and the whole process can performed repeatedly, the smoother the better. Audiences invariably assume at first that there is some sort of trickery going on, and sometimes seem quite disappointed when it is revealed that the juggler is actually just doing precisely what they appear to be doing. Done well, it appears almost as though the ball is doing the moving and juggler's hand follows it, rather than the other way around.
Although this pattern may look simple, contact juggling is a great deal more difficult to perform than it first appears. Juggling three balls is a trick most people can pick up in a day or so, but even basic contact juggling can take several months to master.
There is, as might be expected, far more than just the single pattern. Gliding a ball smoothly from one hand to the other and back is a graceful trick, and there are many variations using two or three or more balls, exchanging from hand to hand. Many contact juggling routines incorporate elements of mime, in that the crystal can appear to have a mind of its own, attempt to escape and so on. Other variations include rolling two balls smoothly around the palm of the hand - a trick popularised recently by the ubiquitous 'Bao ding' balls which come with built in chimes. This can be extended to three, and for the crowning glory, placing a fourth ball on top of the three to form a whirling pyramid.
Going further, contact juggling is possible with other props, including beach balls, trays, hoops, knives and poles. Anything involving maintaining contact without maintaining a grip on an object could be considered contact juggling.
Contact Juggling in Films
David Bowie's character in the Jim Henson film Labyrinth does some impressive contact juggling, thanks to the world's foremost exponent of the art, Michael Moschen. A viewing of this film is strongly recommended to anyone interested in contact juggling.
Finding Out More
An excellent book, Contact Juggling by James Ernest, is available from good juggling shops.
Talk to a juggler. Jugglers are the opposite of magicians, they almost invariably actively want other people to know how they do their stuff. One of the reasons is that jugglers generally tend to be friendly, sharing types. Another reason is if you try to do what they just showed you, you appreciate even more just how hard it is!