The rock was only lightly attached to the black earth, so I pulled it free. It was the size and shape of a large pineapple; it was grey but it glinted. It was a bright alien among dull commoners. I realised it had been hewn by hand: I could see chisel marks pocking its surface. Turning it around, I found a perfectly round opening at one end. I grabbed a twig to probe inside. Under a cobweb and a dried bug or two was hard-packed earth.
Once cleared, the cavity was about two-thirds of the rock’s full length. Peering inside, I saw that it was of remarkably uniform diameter throughout, and it had a finely cut notch running down into its chamber from the lip. Near the base of the chamber was a small hole. Originally, the rock’s chamber had held gunpowder. The notch and the hole were surely clues as to how it was detonated.
Later, I returned to the location to measure the distance from the Wall and observe the lie of the land. As I did, I found more mines, some whole, some broken into pieces. The gully was fifty metres or so in front of the Wall, and it appeared to have been a minefield.
The igneous rock used for the mines was crystalline and coarsegrained, dark-grey with a greenish tinge; once seen, it couldn’t easily hide among the native limestone. My eyes became accustomed to its distinctiveness, and it soon reappeared, this time on the Wall itself, peeping out from the rubble of a watchtower. I scratched around it and freed it from the debris. It was a similar mine-type weapon.
Although this watchtower weapon had the same cylindrical shape and rock type as the landmine, there were two differences: it was much smaller, approximately half the size and weight, and it lacked any ignition hole. In the same ruined tower – in fact, within the same square metre – I discovered two more weapons, roughly the same size and shape. I’d found what remained of a watchtower’s arsenal.
Both these ‘off-Wall’ and ‘on-Wall’ weapons were made of the same rock, not easily sourced, which had been shaped cylindrically and were strong enough to withstand the explosive forces created inside. They effectively functioned as stone cannon barrels that would explode at some distance from their operators. Although the weapons looked the same, their differences strongly suggested different methods of ignition. The larger examples, at eleven to fifteen kilograms, were too heavy, and were found too far from the ramparts, to have been thrown. They had been planted in front of the defences, in a gully through which any enemy had to pass: these were the dilei, or landmines.
DESCRIPTION: Shipao and dilei, or ‘rock bombs’ and ‘landmines’; carved chunks of rock that were hollowed out to hold gunpowder; ranging in size from fifteen to thirty-two centimetres high, twelve to eighteen centimetres in diameter, and five to fifteen kilograms in weight
SIGNIFICANCE: Purpose-made, either to be dropped as rock bombs from the Wall’s ramparts or buried as landmines in front of the fortifications
ORIGIN: Made in the 1570s in the Beijing region; discovered in Huairou District, Beijing, in the late twentieth century
LOCATION: Author’s collection, Beijing
The smaller pieces, weighing five to seven kilograms, were light enough to be pitched a few metres. The fact that they were found in watchtowers, which are known to have served as storage facilities for weapons, suggested that they were deployed either from that position or from the adjacent ramparts. They might have been tossed over the battlement or dropped out through its loopholes, and would explode just below the battlement. These were shipao, or rock bombs.
As a geographer-geologist by training, I was not only impressed but also somewhat mystified by the work that must have been expended to produce just one of these stone weapons, let alone thousands or tens of thousands. Each was hewn on the outside and hollowed on the inside. There was a high degree of uniformity in their cylindrical design. Did they need to be sculpted so precisely? More challenging by far was the task of hollowing out the gunpowder chamber, which had a remarkably smooth consistency. In sixteenth-century China, when these rock bombs were made, there were no drills capable of cutting granitic rocks. Masons had to rely on technology, not on the hardness or strength of their tools.
Rudolf Hommel, while travelling through China in the 1920s, noted the use of the ‘bow drill’ for boring into and cutting stone. The broken landmines I’d collected allowed me to examine the interior surface of the chambers. I found both vertical marks, indicating chiselling, and fairly smooth curved surfaces, suggesting drilling. An abrasive interface, such as quartz sand under a drill head, could have done the job, if the drill shaft was held stable by one person and rotated rapidly (in push and pull fashion) by two others. They would all be working for a long time.
The wonderful title of Hommel’s book – China at Work: An Illustrated Record of the Primitive Industries of China’s Masses, Whose Life is Toil, and Thus an Account of Chinese Civilization – discloses all the methods upon which the manufacture of these weapons must have depended: it was primitive toil, done by the masses. The book’s expressive title also outlines a time-honoured approach that had been paraphrased in ancient times by the idiom shui di shi chuan: dripping water pierces stone. Recent experimentation by Egyptologist Denis Stocks has shown that a team of three persons – one pushing the tubular copper ‘drill’ head down, and two others pushing and pulling the bow drill shaft to generate its rotation on abrasive quartz sand – could achieve an impressive drill rate into granite of two centimetres per hour. Based on such a figure, we can suppose that it may have been feasible for a gun-powder chamber in a medium-sized rock bomb to be drilled in a single long day’s work.
So much for the labour, but what about the technology behind its detonation? It is obvious that these two weapons – mines and bombs – would have utilised different methods of ignition, as indicated by the small fuse holes penetrating the mine casings and the neatly cut grooves running down into the chambers (possibly a backup detonation arrangement). The missing links in their operational mysteries can be found in the Huolongjing, an outstanding treatise on hot weapons compiled by Jiao Yu, who lived from the mid-fourteenth to the early fifteenth century. He was a military strategist who played a key role in the Han rebellion against Mongol rule that saw Zhu Yuanzhang found the Ming Dynasty and become its first emperor, in 1368.
One version of the book’s complete name, ‘Illustrated Fire Dragon Technology of Magically Efficacious Weapons’, is no exaggeration. In this compendium of explosive weapons science we find descriptions and woodblock illustrations of a veritable storm of late-fourteenth-century killing technologies: ‘sky thunder’, ‘water thunder’, ‘ground thunder’ and ‘human thunder’, known to us as rockets, sea mines, landmines and handheld weapons.
Although six centuries have passed since it was compiled, the Huolongjing has a distinct science-fictional feel, but back then it was accurate scientific fact – and top secret. Jiao Yu believed the revolutionary arsenal he was describing had been decisive in the Han’s ousting of the Mongols, and like many an author he felt the need to record his knowledge for posterity. ‘Lest these weapon techniques might be lost during a long period of peace, I endeavour to illustrate them with diagrams and describe them in words,’ he wrote in his preface, dated 1412.
Concerning shicha pao, or ‘stone-cut explosive landmine’, the Huolongjing says:
This is a piece of rock carved into a spherical shape, and it can be of various sizes. Inside it is hollow, and contains explosive (formula) gunpowder which is packed in tight with a pestle to fill up nine-tenths of the space. A small section of bamboo is inserted for the fuse. The gunpowder is covered with a piece of paper, above which is placed some dried earth . . . for the defense of cities the landmine is buried and hidden underground, and this is what is used for ground thunder.
The Huolongjing does not specifically mention the use of shicha pao at border defences, but that is understandable: the technologies described in the treatise were used primarily during the period of insurgency to overthrow the Mongols, and in the pacification of the north that followed. By the early Wanli Period (1572–1620
), soon after Qi Jiguang had taken command of the Ji Military Region, in the 1570s, we know he had purpose-made pavement-level openings called shilei kong, or ‘rock bomb holes’, built in the Wall’s battlements, most famously at Jinshanling. These permitted the targeting of dead ground at the foot of the Wall, seven to nine metres below.
The weapon’s base, being heavier than the hollowed-out section, helped the muzzle end of the bomb point upwards as it fell, for maximum impact. Clearly, precision timing was everything, and bombs would be lined up in readiness. The chamber’s uniform diameter enabled efficient packing of gunpowder. Fuses would have had short ignition times – a matter of seconds. If it was too short, the operator would be decimated. If too long, the enemy would have time to escape the area, or perhaps even pick up the bomb and throw it back.
These weapons were probably used in fairly large numbers, thus creating a highly dangerous zone. The Huolongjing describes a variety of specialised gunpowders – of irritating, burning, poisonous and blinding types – and advises the use of shrapnel, all of which would have made being in a bomb’s vicinity extremely hazardous. This chemical component would have made it extremely difficult for the enemy to throw back any rock bombs.
While a besieger might expect bombs to be launched or dropped from defensive ramparts, he was less likely to anticipate landmines. A number of mines are described in the Huolongjing, but their methods of detonation are kept mysterious. Of the wu ti di lei pao, a mine described as having a metal case, the book merely says that ‘at a given signal the mines are exploded, emitting flames, fragments and a tremendous noise’. I agree with Joseph Needham’s view in volume five, part seven of Science and Civilisation in China, dubbed ‘The Gunpowder Epic’: ‘one has to suppose that a long fuse was ignited by hand from an ambush or some sort of concealment just at the right time. The speed of transmission along the fuse would have had to be nicely calculated.’
The fuse was likely to have been braided hemp, generously impregnated with gunpowder of the fast-burning (not explosive) formula. It’s possible that wet-weather problems might have been solved by housing the match cord within a damp-proofed (oiled) bamboo tube, cleared of its septa and with air holes drilled.
While such a setup might appear complex and unreliable, it sounds much simpler than the zifan pao or ‘self-tripped trespass mine’, also described in the Huolongjing.
It is made of iron or rock, or even porcelain or earthenware, with a cavity inside, very like the shicha pao or ‘stone-cut explosive bomb’ [mentioned above]. Outside, the fuse runs through a series of ‘fire ducts’ which connect together several of these devices installed at strategic points. When the enemy ventures on to ground containing one of these mines all the others are set to explode quickly one after another.
‘Fire ducts’, however, would merely have transmitted the fire. The question of how some kind of automatic ignition system might have worked is only vaguely referred to:
The hollow, explosive mine has black powder rammed into it. A thin bamboo tube is inserted, which in turn houses a fuse, while outside the mine a long fuse leads through fire ducts. Pick a place where the enemy is likely to pass through, dig pits and bury several such mines in the ground. All the mines are connected by fuses through the gunpowder fire ducts, and all originate from a steel wheel (ganglun) . . .
It was two centuries after the Huolongjing’s reference to the origin of the spark – the ganglun, or steel wheel – that other military works finally explained how it worked. Ping Lu, or ‘Military Arts’, printed in the 1620s, describes it as consisting of jagged-edged steel discs and a drum affixed to an axle. Around the drum was a length of cord with a weight attached to its end, beneath which had been dug a deep pit. An enemy would unknowingly break a string or cause a pressure-sensitive pin to be released; the weight would fall down into the pit, rotating the axle, spinning the discs to grate on flint, and creating sparks that would ignite the gun-powder and explode the mines. Although it has been described and illustrated, this flint ignition system has never been discovered, and probably never will be.
I found stone mines to be very rough in appearance, and I discovered them to have been used in very specific locations. I came to appreciate that they relied on highly skilled operators, and perhaps on extremely complex ignition technologies as well. Stone they were, but stone-age? Definitely not.
34.
A Bird’s Eye View
Fired-clay roof guardian
I’ve taken an unconventionally broad and multidisciplinary approach to finding out all I can about the Great Wall, employing the fitness of an athlete, the guts of an adventurer, the mind of an historian, the hands of an archaeologist, the eyes of a photographer, the perspective of a geographer and the heart of a conservationist.
If I had to privilege one of these disciplines, though, it would be archaeology. There, the whole subject depends on finding a solid source, which more often than not is rendered incomplete by the vicissitudes of time. What’s missing provides an opportunity for informed speculation, imagination. What could surpass the thrill of being the first person to hold an object for hundreds or thousands of years?
This little bird fits into that category, and in my hand. It’s a figurine that was placed on auspicious guard duty on the roof of a watchtower: it’s known as a roof guardian. Soon after I discovered it, bringing it back to the light for the first time in centuries, I took this photograph of it: a phoenix reborn.
I used my geographer’s logic in naming it. As it was found near Wulonggou, or ‘Black Dragon Gully’, I dubbed it the ‘Black Dragon Phoenix’, a curious but fitting name. For one thing, it’s actually made of grey brick, but it stood behind a dragon as a subordinate for much of its working life.
It’s in two main parts and has a broken neck: whose wouldn’t be, if one had fallen three metres onto the ground? Fortunately, the pieces fit together perfectly. Its features are detailed, though rough. You can see plumage flecked on its bulbous body, particularly on both wings and its plump chest. Its tail feathers are stubbed, and its short legs, which anchored it to a roof tile, are missing. The bird’s long neck and head show a flowing mane, an upright crest, a curved beak and eyes deeply set in their sockets.
It’s an odd bird – not natural but mythical. Rare, too, not being mass-produced at a kiln. It’s fairly unique, and that makes it an object of crude beauty. It’s made of the simplest and cheapest of materials: the same clay used in the Wall’s brick battlements, and for the slabs on the Wall’s pavement. Those were produced on a huge scale, and were standardised (see Object 6). That was production-line manufacture, but this phoenix was small-scale, handmade. It bears all the marks of its maker.
I can imagine him, having been assigned the job by his section foreman. His task? To make enough figurines to perch on the tops of two adjacent towers which were nearing completion at either end of an eighty-metre stretch of Wall.
At the valley kiln site, he took a lump of clay over to a flat boulder that functioned nicely as a table, sat down in front of it and started clawing away pieces with his fingers. The form of a creature began to appear. Now he used his fingernails and palette knife, and from his whittling a mythical bird began to take shape.
He wasn’t a sculptor, not even an artist, just someone who had proved he could do a good job before. Other workers likely gathered around, watching him as he worked, entranced by seeing something rare: not just another brick for the Wall but the creation of an ornament. Some gave advice, encouragement, jovial criticism, for these were golden autumn days for most workers now, the first respite they’d had in more than ten weeks of relentless toil. The outstanding tasks were easy, minor, even pleasurable, compared with the earlier backbreaking toil of levering, lifting and winching quarried blocks, and carrying and laying thousands of bricks.
DESCRIPTION: The Black Dragon Phoenix, a roof-guardian figurine; fired clay (brick), seventeen centimetres in height; made circa late-sixteenth century
SIGNIFICANCE: An a
uspicious roof-tile ornament from the ruins of a watchtower sentry-post on the Ming Great Wall
ORIGIN: Upper level of a watchtower, two kilometres west of Wulonggou, Laiyuan County, Hebei Province
LOCATION: Author’s collection, Beijing
All that remained to be done now was wait for the figurines to come out of the kiln, nestle them in straw, pack them into baskets and carry them up the long mountain path to their places of duty.
Roof guardians were believed to keep the watchtowers safe, along with all the men to be garrisoned in them. Our man had created not only the organic from the inorganic, animal from mineral, but also objects of spiritual significance. But these scarecrows were never going to faze attackers. Their function was auspicious, to bring luck to those on duty: they gave them peace of mind, and perhaps a moral boost. The placement of roof guardians on any building in the Great Ming Empire branded it as official imperial rank.
Along with the dragon, the phoenix was one of up to nine semi-mythical, animal-like figurines that graced the roofs of buildings of imperial importance. One of the earliest references to roof-tile ornaments is found in an eleventh-century Song Dynasty construction manual, Yingzao Fashi, or ‘Treatise on Architectural Methods and State Building Standards’. Compiled by Li Jie (1065–1110), the book covers every aspect of building work, from laying foundations to putting up roofs, from carpentry to stonework, from budgeting to ornamentation. However, the construction protocol guidelines began to take form from Zhou Li, or the ‘Book of Rites of Zhou’, one of the Confucian classics.
Roof guardians are rare exhibits in most museums, until the Ming. The oldest in situ specimens are only found on the best-preserved palatial buildings, most notably on the repaired roofs of Beijing’s Imperial Palace. Visitors are intrigued when they spot rows of tiny figurines standing in a line along the hips of the golden-glaze tiled roofs. The creatures remain frustratingly mysterious for various reasons: their tiny size, inaccessible locations and auspicious meanings. The numbering guidelines, however, were reasonably straightforward.
Great Wall in 50 Objects Page 17
