Astrology is a subject that bothers people. Even if they scoff at the whole idea, they may furtively scan their newspaper horoscope, haunted by a hunch that just maybe there is something in it after all.
Tonight a lawyer-turned-counsellor, a record producer, a New Zealand child-minder and a Rowan Atkinson lookalike are among the dozen men and women sitting round a table listening earnestly to tutor Kim Farley. She fits the bill as an astrologer - a tall, elegant woman with a cascade of curly hair, star-shaped earrings and an outfit in shades of burnt orange. Surely she must be a fire sign.
Kim is all warmth as her proteges step in from the cold, wet street. "Welcome back, my lovelies. Missed you all." It promises to be a somewhat stagey evening, but within minutes Kim has everyone's attention and is setting her students little tasks to help them to recap what they learnt in their last session.
As the evening progresses, she switches from a cosy and almost patronising approach to one of extraordinary fluency, rapidly dealing with a mass of seemingly complex theories and mathematical phenomena. She is indeed inspirational; it is not hard to see how some of the class's sceptics have been won over to the wonders of astrology.
Kim herself is not interested in persuading people to believe, but rather in expounding the theories and explaining interpretations.
"I started on a course just like this in 1989," she says. "I saw what it offered, and spent six years getting my diploma. Now I am a member of the Faculty of Astrological Studies. For me astrology is about what things mean - not predicting what is going to happen.
"I enjoy getting people to think about it. Yes, I do sometimes skim through newspaper horoscopes, but when you reduce a complex issue to a few lines it makes it all very banal. The skill of newspaper astrologers is in the writing, more than anything else; unfortunately, real astrologers don't make that sort of money."
The 20-week course, run by Kensington and Chelsea College for Adult Education, is open to complete beginners or those who have already dabbled in aspects of the planets and elements. The introduction deals with the astrological alphabet relating to planets, elements and what are called modes: cardinality, fixity and mutability.
Kim starts this evening's two-hour session by inviting everyone to imagine a circus, and then to relate different circus acts to each sign of the zodiac - based on knowledge gleaned about the signs from earlier sessions.
This is good fun, if a little basic. The untutored would guess that a fire-eater might correspond to the fire sign of Aries, or that Siamese twins could be represented by Gemini, but the more expert come up with intriguing options. The sign of Taurus was associated with elephants and other animal acts but also with meticulous financial business, and would therefore be most likely to represent the cashier or ticket collector, or even the financial backer of the circus. High-wire acts were associated with Libra, psychic mind-reading and snake-charming with Scorpio, sad clowns with Capricorn, and dog acts with Virgo. And so it went on.
The next exercise dealt with the 10 basic "planets": Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. This time Kim asked the class to imagine a brick wall and how the spirit of each planet might react to it. Well, that got them going. A random vox pop suggested that Venus would have a smooch under it, Mars might have a quick one up against it, and Pluto would be more into putting black-tinted mirrors on it.
Not that every reference was about sex. Saturn would build a scaffold around the wall, Neptune might dance to music beside it, and Mercury might play games against it.
When Kim switched the easy exercises to describing the 12 houses in astrology, the novice - such as me - was lost, but I could see how enraptured the rest of the class remained. They had all done their own chart and had studied the charts of some celebrities, including Judy Garland and Germaine Greer, to get a feeling of how to interpret a wide range of information offered by the circumstances, place and time of the subject's birth.
Dare Mason, a record producer, said that he had been sceptical, but was moved to give the course a go because he had met several astrologers and had been impressed with what they said. "I was just amazed at how accurate my chart was. What I am learning now is the complexity of interpretation."
Lindsay, an erstwhile lawyer from London who had changed her profession to counselling, said she used her knowledge of astrology to help assess her clients.
"I have consulted an astrologer more than once, and each time I was very impressed. This is the first course I've been on, and I've found it fascinating."
Kim Farley's 20-week course at the Kensington and Chelsea College costs between pounds 76 and pounds 92 (0171-573 5333). She also offers private consultations in London (0171-403 6215). Information on courses in other parts of the country can be obtained from the Faculty of Astrological Studies in Orpington, Kent (07000 790143).