At last, a major novel has appeared in which the hero is a juggler. The book is Lord Valentine's Castle, by Robert Silverberg (Bantam Books, paper­back, 447 pages, $2.95), a well-written fantasy with elements of science fiction skillfully blended in. It also contains some surprisingly accurate descriptions of both the physical and mental processes involved in juggling.

In a preface, Silverberg acknowledges the technical assistance of jugglers Catherine Crowell and the Flying Karamazov Brothers, and in my opinion, he made good use of their expertise.

The story is set on the distant planet of Majipoor, far removed in both time and space from present-day Earth. It is populated by at least a dozen non-human races plus a minority of humans. The main character, suffering from amnesia at the beginning of the story, meets a wandering troupe of jugglers who offer to teach him their art. He learns quickly and hires on for a tour of the countryside.

The tour, however, soon turns into a quest which carries the small band of performers across the length and breadth of Majipoor. As the true nature of the quest is not made clear until midway through the book, I shall not reveal it here. Suffice it to say they have plenty of exciting adventures along the way.

Besides our hero, the juggling troupe includes two other humans and six Skandars, huge shaggy creatures with four arms apiece. And they are the least unusual of the beings that the reader will encounter in this book. Silverberg has a great imagination, and a real gift for describing fantastic flora and fauna in such a way that they seem quite plausible.

As mentioned earlier, the descriptions of juggling in this book are what makes it stand out. The chapter in which the hero is being taught to juggle is particularly well done. I think a person could almost learn the basic cascade from reading that section.

And the instruction is not dull reading either, for Silverberg translates the familiar "Carlo method" into the language of fantasy.

For example, the student is told to hold his arms just so and imagine that a tray of precious gems is resting on them. Later in the book, there is mention of half-juggling, take-aways, blind-folded juggling, and various passing patterns, including feeds and back-to-back passing. Although this is a fantasy, with sorcery and dream manipulation, the juggling is all quite down-to-Earth (if you'll forgive an inappropriate metaphor). Perhaps most importantly, Silverberg gives the reader a feel for the satisfaction and inner peace one can obtain when juggling.

(Even if you don't read the book, you should go to a bookstore and look at its beautiful cover painting. You will be amazed to see an accurate portrayal of juggling, i.e., objects in the hands as well as in the air. The artist is not credited in the book, but he or she produced a marvelous work of art. Several jugglers are shown at an outdoor festival, surrounded by an audience of many races, both human and other­wise. The performers include a woman with three clubs, a man juggling balls and a trio of the four armed Skandars passing daggers.)