by Eric Flint
“Napalm. Our particular version of Greek Fire.”
“And you know how to make it? And do we have the ingredients in town?”
“I was at the siege of the Wartburg in 1631, where it was used. And later I was in USE Intelligence. So, yes, I know. As for the ingredients…” Eric turned to face Fang Kongzhao, who had accompanied von Siegroth.
“Do we have shíyóu—‘rock oil’—in town? If so, we can distill off the gasoline and use that. Napalm is a jellied gasoline.”
The first oil wells had been drilled in China, twelve centuries earlier. The oil had been discovered when the Chinese drilled for brine, and the oil was used mostly as a fuel, to evaporate brine to make salt.
Now it was Fang Kongzhao’s turn to shake his head. “Not a great deal. You wish to use it as an incendiary? During the Song dynasty, the Wujing Zongyao, that is, the ‘Collection of the Most Important Military Techniques,’ was published. It says that in the defense of a city, rolls of blazing straw may be thrown down onto the assault bridges, and that if one uses ‘fierce fire oil,’ water will not put it out.
“The ‘fierce fire oil’ is made from rock oil. The shíyóu is common in Sichuan, because that’s where it is produced from the earth, but here we mostly burn wood, coal and dung. I am sure that we can find apothecaries with some. But the quantities will be limited.”
“If you have coal, then we can make ‘coal oil’: kerosene. I think that might work,” said Eric.
“Even if we don’t have enough petroleum or coal, surely there are animal and vegetable oils in town. Can we make this napalm from them?” asked von Siegroth.
“If we can get them to gel. I would assume that we would have to distill the vegetable or animal oil to give it the right physical properties. Is there a perfumer in town, perhaps?”
Before Fang Kongzhao could answer, von Siegroth said, “Whether there is or isn’t, Judith Leyster knows more than a little about distillation. She paints with oils, and she surely knows how to make her own paints and varnishes.”
“This sounds like an idea worth pursuing,” said Fang Kongzhao. “At least if you can do it without burning the town down in the process. Please speak to Judith Leyster, and Yizhi and I will round up those townspeople we think might be able to help. How are you thinking of delivering this ‘napalm’? We do not have any ‘fierce fire oil shooters’ in the town armory.”
The colonel’s eyes widened. “You have flamethrowers in China?”
“A flamethrower, as you call it, was described in the Wujing Zongyao. It has a four-footed brass tank, with vertical tubes feeding a horizontal cylinder. A pump handle moves back and forth inside the cylinder, sucking the fire oil up into the cylinder and then spraying it out a nozzle on every stroke. In front of the nozzle, a fuse is held, to set the oil on fire.”
Von Siegroth nodded. “So it needs a two-man crew, one to pump and one to hold the fuse.”
“Sounds interesting, but too complicated to make in the time we have,” Eric complained. “We have catapults, can we use those to throw the napalm?”
“Yes, but not very accurately,” said the colonel. “The near bank of the moat is thirty paces away. Since the catapult employs arcing fire, it has poor distance control, and is optimized for a greater range.”
“Can we throw them, like a Molotov cocktail?” Eric wondered.
“I am not familiar with that device,” the colonel answered, “but if it’s like a grenade in size, shape and weight, the average soldier can throw one perhaps forty yards. That’s a little shy of the far side of the moat, but with the advantage of height from being on the rampart, maybe.…”
Chapter 47
Ninth Month, Day 15
Judith Leyster had made linseed oil and poppyseed oil as oil-paint media, and turpentine as a thinner. It had never been her goal to set her paints on fire, but she supposed that there was a first time for everything. She had to admit that there were a couple of paintings she wanted to burn after the fact.
Before she started experimenting, she had laborers remove all unnecessary flammables from her work area, and set out a big pot of sand. She also wore several layers of clothing, plastered with mud.
Judith first heated coal, obtaining a clear liquid that burned nicely when placed in a lamp. That, she hoped, was Eric’s kerosene. She also found that tung oil, of which Tongcheng had plenty, could be gelatinized by heating it. She fiddled with adding other oils and finally had a gel she liked that would mix properly with the kerosene. At Eric’s suggestion, she also tried shaving some of the Chinese soap and using that to gel the kerosene.
Since Eric was a long-range shot and Mike Song wasn’t, Mike was deputed to help her. Which essentially meant that Liu Rushi joined the team, too.
They prepared very small samples, with long fuses, and set them off, first on dry wood and then on wood in water. Eventually they came up with a composition that was good enough, they hoped.
The next step was to come up with the grenade housing. While the classic Molotov cocktail was served in a bottle, China didn’t have much of a glass industry, so their grenades were pottery containers. They would also break on impact, spraying the flaming contents.
When Eric Garlow came by to pick up the sample grenades for testing, she told him, “Much as I want to drive off those horrible bandits, I see this as a last resort.”
He nodded his agreement. “I will be very happy if the Ming army comes to the rescue and drives them off, before we have to use it.”
* * *
An attack on the south gate seemed to be the enemy’s likeliest move once the moat was bridged. Colonel von Siegroth had decided that it was time, past time, to prepare one of the volley guns for close-in defense of the south gate from one of the flanking mamian. That unfortunately meant taking it out of commission for some hours, but it was better to have it ready once the enemy bridged the moat and attempted an escalade. If enough bandits were killed at that point, it might persuade the enemy to give up the siege.
Modifications had been made to both the volley gun and the parapet in order to render the volley gun more effective.
Eric Garlow liked to think of the volley gun as the “xylophone from Hell.” Imagine a xylophone mounted on a wagon wheel axle, with the wheels still attached. Replace the xylophone bars with two-foot-long rifle barrels, and attach underneath the axle a trail like that on a field-gun carriage, and you essentially had a volley gun with its standard mount. The wheel axle doubled as the pitch axis of the volley gun. The barrels and breechloading mechanism of the volley gun rested on a bed, which was equipped with grips to engage the axle. The bed and breechloading mechanism gave the volley gun a “preponderance,” that is, it was heavier at the breech end than at the muzzle end. This caused the bottom of the bed to remain seated on the top of the elevating screw. The screw ran through a socket on the trail of the carriage, and was moved up or down by turning a spoked collar threaded onto the screw. When the screw moved up it pushed up the breech end of the bed, depressing the muzzles.
Normally, the elevating screw allowed a range from fifteen-degree elevation to fifteen-degree depression. However, for use on a city wall, a steeper depression was desirable.
Ideally, the elevating screw would just be replaced with a longer one. Unfortunately, the metalworkers of Tongcheng seemed completely unfamiliar with the screw, there was no screw-cutting machinery in town, and in any event there was no time to make one from scratch. So Colonel von Siegroth had to find a workable field expedient.
This took the form of a wood piece, the bottom of which fitted over the top of the elevating screw, and the top of which cradled the bed. The colonel would have preferred an iron piece, but there wasn’t time to make that, either. Anyway, wood should serve. The quoins used for gun depression before the Ring of Fire, and for that matter as late as the former nineteenth century, were merely wooden wedges.
The colonel had shown the wooden piece to Mike Song, who called it a “kludge.” Colonel von Siegroth indic
ated that in his reading of the admittedly limited Grantville literature on ordnance, he had not come across that term. Mike Song assured him that it was the best possible term in the English language for the expedient, and so the colonel bowed in thanks, and adopted the term. The “kludge” was long enough to shift the range of pitch to be from zero degrees elevation to thirty degrees depression. The base of the parapet was thirty-three feet high, and the pitch axis of the volley gun three feet above that, so at thirty degrees depression, the adjusted volley gun could hit the chest of a man standing a mere nineteen yards from the base of the wall.
The second problem was that the volley gun had a width, wheel to wheel, of six feet, whereas the embrasures were a mere three feet wide. It would not do for half the barrels to fire upon the parapet rather than the enemy! Hence, the embrasure of choice, facing westward toward the south gate, had to be widened by removing part of each of the two flanking merlons. This was easier than one might think; the merlons weren’t solid rock, they were made of bricks, and rather large bricks at that.
Once night fell, a couple of bricklayers were summoned to the battlement, and they chiseled away at the cement holding the unwanted bricks together. The bricks were carefully removed and stored—the battlement would need to be restored once the volley gun was no longer emplaced there. The embrasure was widened enough that the carriage could be rolled in so that its wheels lay partially between the merlons. The bricklayers also removed a part of the sill of the embrasure, lowering it a bit and also creating a depression channel. That was a crude diagonal slot so that the volley gun, standing just behind the parapet, would have a clear thirty-degree angle of depression.
Finally, several carpenters had created a stout rectangular wooden shield, to give some protection to the volley-gun operators. This wooden armor was attached to the parapet, and not to the volley gun, and so the volley gun could still be moved somewhere else. The shield was mounted in a slotted wooden frame, so it could be raised or lowered. In the raised position, the shield would protect the gunners from enemy at a distance, but allow them to see and shoot at the enemy close at hand. Of course, the latter would be able to shoot them, too.
* * *
One of the art teachers in Grantville had shown Judith Leyster a picture of her 1633 painting, “Mother sewing with children by lamplight.” It had, frankly, given Judith the creeps, because in this timeline she had only done a preliminary sketch for it.
Not liking the notion that her art was dictated by the cold hand of Fate, she had instead painted a Grantville scene, a knitting bee. Women were gathered together, knitting and gossiping.
She was reminded of that knitting bee painting now. She, Liu Rushi, Fang Weiyi, and other Tongcheng women were gathered together, working and chatting companionably.
However, instead of knitting, they were making napalm grenades.
Even as Judith, Mike and Liu Rushi worked on the incendiary grenades, and the colonel on preparing the volley gun and its mamian, the bandits continued work on bridging the moat. This time, the enemy committed large numbers of horse-archers to sweeping the south battlements with arrow fire, attempting to keep the defenders’ heads down.
“I hadn’t expected so many of the bandits to be mounted,” Eric Garlow complained to Fang Yizhi.
“That’s why it has been so difficult to defeat the bandit armies,” Yizhi said. “They move five times as fast as the government forces.”
Besides trying to suppress the defensive fire, the bandit commander had given his laborers some passive protection, in the form of shield carts that conveyed them to the moat. These were pushed from behind. The pushers were vulnerable to diagonal fire, of course, but the bandits had plenty of prisoners to use for this labor.
Despite the defensive fire—mostly arrows, since the visitors were conserving their ammunition—the bandits succeeded in laying fascines all the way across the moat, creating the foundation for a bridge across which they could attack the south gate.
The south gate was not a simple door. Rather, the southern entrance to the city was actually a tunnel, three zhang wide, running though the ten-zhang-thick defensive wall. At both the outer and inner end it was closed by a stout wood double door, faced with sheet iron. Thousands of iron nails were hammered through the sheet metal into the woodwork to render it proof against fire, and the doors were barred shut with iron-wrapped crossbars. An iron portcullis could also be dropped into the middle of the tunnel, or raised by iron chains attached to a windlass located in a chamber high above the tunnel.
Fang Kongzhao decided that they needed to set fire to the fascines without further delay. But neither ordinary fire arrows, nor ones dipped in Judith’s napalm formulation, were successful. The fascines were too wet to be burnt by an ordinary incendiary, and the arrows didn’t carry a sufficient payload of the napalm to be effective. Unfortunately, the napalm grenades weren’t ready yet—the first ones made had proven to be duds, and Judith was tweaking the formulation.
That night, Fang Kongzhao opened the south gate and sent out a work party to set fire to the fascines, using Judith’s new formulation, but carried in large pots. This nearly proved to be a disaster. Some bandits had faked death, lying for hours on the far side of the moat. When the work party came close, they rose and fired, killing the sentries standing incautiously in the open outer gate, as well as the work party. And then they descended into the moat, holding their bows aloft so the strings wouldn’t get wet.
The screams of those shot and the splashing of moat water by the onrushing bandits was of course heard by the sentries on the gate tower, but they couldn’t close the outer doors themselves. The best they could do was blow the alarm trumpet and shoot as fast as they could. Both the dim light and the defenders’ anxiety made it difficult to hit the attackers.
Fortunately, before the outer doors had been opened for the work party, the inner doors had been closed and the portcullis in the middle of the gate tunnel dropped. So the bandits didn’t gain immediate access to the town by their stratagem. Moreover, only a few bandits actually made it through the outer doors, as one of the sentries had dropped a “ten thousand enemies” bomb over the battlement just above the gate. This was a fused explosive in a clay vessel, enclosed in a cubical wooden framework. The explosion sprayed shards that killed those of the bandits who were still in the open, but it wasn’t strong enough to damage the gate.
The question remained, had any bandits made it into the comparative safety of the gate tunnel? And, if so, were they few enough in number that it would be prudent to open the inner gate and overwhelm them?
Kongzhao asked for advice, and accepted Sun Lin’s proposal. Some minutes later, several volunteers were lowered over the walls by a contraption that was essentially like a wooden swing, except the ropes were attached to a windlass. Once a large enough party were thus deposited outside the wall, they moved quietly toward the open outer gate, and the “elevator” was lifted back up.
They were commanded by Sun Lin, who motioned for them to halt when they were a few feet from the gate. He was waiting for a signal.
A trumpet blew from somewhere within the gate tower.
Sun Lin started a mental countdown. Five…four…three…two…one… Now. He motioned his men forward.
In the meantime, the rear door of the south gate had been unbarred. The bandits could certainly hear the sound, and knew what that meant—the defenders were getting ready to check the gate tunnel and kill any bandits within.
Then Sun Lin and his men surprised them from behind, quickly killing them all. The bandits’ bows were not well suited to close combat. The men of Tongcheng checked every body—they weren’t going to make that mistake twice—tossed the bodies outside, and closed and barred the outer door.
Sun Lin then took out a horn and blew a special tune. It was the signal to the sentries on the city side that it was safe to open the inner door. They did so, opening it a crack.
Fang Yizhi peered into the gate tunnel. “Sun Lin, I a
m glad to see you are well.” He thrust open the rear doors wide.
He turned, and called out, “It’s our people. Lift the portcullis.”
The portcullis slowly ascended, the mechanism making a grinding sound. Sun Lin and his squad reentered the city, ready to withstand another day of siege.
Chapter 48
Ninth Month, Day 16
The next day was quiet, but the bandit commander was surely contemplating some new devilment.
By now, Judith and her little elves had made several different kinds of grenades. One was of the design that the Chinese called “bee swarm bombs.” Essentially, bamboo strips were woven into the shape of a ball. A bamboo rope was woven into the ball, with either the center loop or the ends exposed. This was all then covered with many layers of thick paper pasted together. An opening was made, and gunpowder and iron fragments poured inside. A fire cracker, placed into the opening, served as a fuse. Judith’s version had a napalm filling instead.
In the “free loop” version, the ball was grabbed by the loop and thrown. Fang Yizhi, however, preferred the other version, as he thought it could be thrown further. Eric Garlow had described it as “an angry baseball with pig tails.” Trials showed that it could be thrown from the height of the wall a good fifty paces.
The ladies had also made “ten thousand enemies” bombs. These had a much larger payload than the “bee swarm” bombs, but were intended to be dropped rather than thrown. Such a bomb was essentially a spherical clay pot, with a firecracker fuse, enclosed in a light cubic wooden frame. When it exploded, the burning napalm would spray over the bandits, sticking to their skin and clothing.
Judith Leyster and Liu Rushi reported to Colonel von Siegroth that the grenades were ready to be distributed.
Ninth Month, Day 17
Once again, the bandits’ captives came forward, carrying boards to lay over the fascines previously dumped in the moat. On Fang Kongzhao’s orders, those approaching the south gate were not fired upon. His intent was to coax the bandits to bring up whatever siege machinery they had, and then destroy it with incendiary and volley-gun fire.