between them and the Jews.”
Master Shi laughed and said, “But there is now—between the Jews and the Han. Do not judge by my looks. It only happens that the Shi family never much intermarried here. Most others of the seven names did. So Kithai is full of Jews with ivory skins and squinty eyes. Only sometimes by their noses shall you know them. Or a man by his gid.” He laughed again, then said more seriously, “Or you may know a Jew because, wherever he wanders, he still observes the religion of his fathers. He still turns toward Jerusalem to pray. Also, wherever he wanders, he still keeps the memory of old Jewish legends—”
“Like the Lamed-vav,” I interrupted. “And the tzaddikim.”
“—and, wherever he wanders, he continues to share with other Jews what things he remembers of the old, and what worthwhile new things he learns along his way.”
He gave no sign of having heard a single word I had interposed, but went right on, “Happily, the Mongols do not discriminate among us lesser races. So I, albeit a Jew, am the Court Firemaster to the Khan Kubilai, who respects my artistry and cares not at all that I bear one of the seven surnames.”
“You must be very proud, Master Shi,” I said. “I should like to hear how you came to take up this extraordinary profession, and how you became so successful in it. I have always thought of Jews as being moneylenders and pawnbrokers, not as artists or seekers of success.”
He snorted again. “When did you ever hear of an inartistic moneylender? Or an unsuccessful pawnshop?”
I could give no answer to that, and he seemed to expect none, so I inquired, “How did you come to invent the fiery trees?”
“I did not. The secret of making them was discovered by a Han, and that was ages ago. My contribution has been to make that secret more easy of application.”
“And what is the secret, Master Shi?”
“It is called huo-yao, the flaming powder.” He motioned me to the work table and, from one of the many jars and phials thereon, he took a pinch of dark-gray powder. “Observe what happens when I place this very little bit of huo-yao on this porcelain plate, and touch it with fire—so.” He picked up a stick of already smoldering incense and applied its spark end to the powder.
I started as, with a quick, angry, fizzing noise, the huo-yao burned away in a brief, intense flash, leaving a puff of the blue smoke whose acrid smell I had come to recognize.
“Essentially,” said the Firemaster, “all that the powder does is to burn with the fiercest rapidity of any substance. But when it is confined in a fairly tight container, its burning bursts that confinement, making a loud noise and much light as it does so. Adding to the basic huo-yao other powders—metallic salts of one kind or another—makes it burn in different colors.”
“But what makes it fly?” I asked. “And sometimes explode in sequacious bursts of those different colors?”
“For such an effect, the huo-yao is packed into a paper tube like this one, with a small opening at one end.” He showed me such a tube, made of stiff paper. It looked like a large, hollow candle, with a hole where the wick would have been. “When touched with a spark at that hole, the powder burns and the intense flame spurting from that aperture at the nether end throws the whole tube forward—or upward, if it is pointed that way.”
“I have seen it do so,” I said. “But
“Come, come, Polo,” he chided me. “We have here one of the first principles of natural philosophy.
“Of course,” I said. “Of course.”
“This being the fiercest of fires, the container flinches away most energetically. So violently that it recoils to a great distance or a great altitude.”
“And,” I said, to show how well I understood, “having the fire in its own vitals, it perforce takes the fire with it.”
“Exactly so. And takes with it more than the fire, in fact, for I have previously attached other tubes around the one that flies. When the first has consumed itself—and I can predetermine how long that will take—it ignites the other tubes. Depending on what sorts I have used, they either explode at that instant, scattering fire of one color or another, or they go flinging off on their own, to explode at another distance. By combining in one engine a number of flying tubes and explosive tubes, I can contrive a fiery tree that sprouts upward to any height, and then bursts into one of various patterns of the sparkling flowers in many different colors. Peach blossoms, poppy flowers, tiger lilies, whatever I choose to make bloom in the sky.”
“Ingenious,” I said. “Fantastic. But the main ingredient—the huo-yao—of what magical elements is it compounded?”
“It was indeed an ingenious man who first compounded them,” the Firemaster concurred. “But the constituent elements are the simplest imaginable.” From each of three other jars he took a pinch of powder and dropped them on the table; one powder was black, one yellow, one white. “Tan-hua, liu and tung-bian. Taste them and you should know them.”
I licked a fingertip and picked up a few grains of the fine black powder and touched my tongue, then said, wondering, “Nothing but charcoal of wood.” Of the yellow powder, I said, “Only common sulphur.” Of the white powder, I said thoughtfully, “Hm. Salty, bitter, almost vinegary. But what … ?”
Master Shi grinned and said, “The crystallized urine of a virgin boy.”
“Vakh,” I grunted, and rubbed my sleeve across my mouth.
“Tung-bian, the autumn stone, so the Han call it,” he said, wickedly enjoying my discomfiture. “The sorcerers and wizards and practitioners of al-kimia deem it a precious element. They employ it in medicines, love philters and the like. They take the urine of a boy no older than twelve, filter it through wood ash, then let it solidify into crystals. Rather difficult of procurement, you see, and in only trifling amounts. But it was specified in the original recipe for making the flaming powder: charcoal, sulphur and the autumn stone—and that recipe was handed unchanged down through the ages. Charcoal and sulphur have always been plentiful, but the third ingredient was not. So there simply was not much making of the flaming powder, until my lifetime.”
“You found some way to procure maiden boys in quantity?”
He snorted, very Mordecai-like. “Sometimes there are benefits in coming from a humble family. When I first tasted the element, as you just did, I recognized it as another and much less exquisite substance. My father was a fish peddler, and to make the fillets of cheap fish look more delectably pink, he soaked them in a brine of the lowly salt called saltpeter. That is all the autumn stone is—saltpeter. I do not know why it should be present in boys’ urine, and I do not care, for I have no need of boys to make it. Kithai is abundantly supplied with salt lakes, and they are abundantly rimmed with crusts containing saltpeter. So, these many centuries after the flaming powder was first compounded by some Han genius of al-kimia, I, merely the inquisitive son of the Jewish fish peddler Shi, am the first to make it in vast quantities, and to make the glorious displays of its fiery trees and sparkling flowers enjoyable by all men everywhere.”
“Master Shi,” I said diffidently. “In addition to my admiration of the beauty of those works, I have been struck by the thought of turning them to more useful account. The thought came to me when my own horse shied and bucked at first seeing a display of the fiery trees. Could not these engines of yours be used as weapons of war? To break up a cavalry charge, for example?”
He snorted yet again. “A good idea, yes, but you are more than sixty years late with it. In the year when I was born—let me see, that would have been by your Christian count the year one thousand two hundred fourteen —my native city of Kai-feng was first besieged by the Mongols of the Khan Chinghiz. His horse troops were affrighted and dispersed by balls of fire which flew into their midst, trailing sparks and whistling and banging. The Mongols were not stopped for long, needless to say, and they eventually took the city, but that valiant defense contrived by the Kai-feng Firemaster became legendary. And, as I told you, we Jews are great rememberers of legends. Thus it was that I grew up enthralled by the subject, and finally myself became a Firemaster. That employment of the flaming powder at Kai-feng was its first recorded use in warfare.”
“Its first,” I echoed. “Then it has been used since?”
“Our Khan Kubilai is not a warrior likely to ignore any promising tool of war,” said Master Shi. “Even if I were not personally interested in trying new applications of my art, and I am, he has charged me with investigating every
