HMS Volage and HMS Hyacinth confront Chinese war junks at Chuenpee, 3 November 1839.
The British repulse the Chinese advance in the city.
Today many prominent historians downplay the role of science in the rise of the West, and the topic has aroused considerable discussion. As usual most of this debate has focused on economic history, and it’s been hard for either side to sway the other, largely because the links between science and economic growth are difficult to pin down for the period when the Great Divergence was opening up, to wit the 1700s.
But if the links between science and eighteenth-century economies remain unclear, there’s no doubt about the links between science and the eighteenth century military divergence. European advances in gunpowder manufacture and gun design were based on discoveries from experimental science, and those advances played a key role in the British victory in the Opium War.
Before the mid-eighteenth century, people did not understand some very basic things about guns and gunpowder. What was the precise relationship between the amount of gunpowder used, the shape of the barrel, and the velocity of a projectile of a given mass and size? How much air resistance did the projectile face once it exited the barrel, and how did that resistance affect the trajectory?
In the seventeenth century, Galileo and others had developed a theory of ballistics and put together tables to help artillerists—Galileo had even developed instruments for aiming cannons, which brought him significant income. Over the ensuing generations, others had refined these tables and instruments, but by the mid-eighteenth century these tools were still inaccurate, useful for a limited range and only in certain conditions.
In order to develop more effective models one needed to know how fast projectiles came out of guns. It wasn’t an easy problem. Enter Benjamin Robins (1707–1751). A disciple of Isaac Newton, Robins developed an instrument that transformed the science of guns: the ballistic pendulum. It was a tripod the height of a tall man with a heavy pendulum hanging down from it. On the pendulum was affixed a target. The experiment started with the pendulum at rest. When struck by a projectile, the pendulum swung upward. By measuring how high it went one could determine the projectile’s momentum, and using Newtonian models one could calculate its velocity.
The ballistics pendulum revolutionized gunnery. The most exciting findings had to do with the effect of air pressure on projectiles. Galileo had dismissed the effects of air pressure in his work on ballistics, and Newton, too, underestimated it, or, rather, expected that its effects were linear at increasing speeds. But Robins showed that air resistance was incredibly significant. Whereas then-current models predicted that a twenty-four-pound cannonball should, at the muzzle velocity Robins had measured, fly sixteen miles, in actuality it flew only three. Air resistance was thus much higher than expected. Even more surprising was the nonlinearity of the results. The higher the muzzle velocity, the greater the effect, with extreme drag as you approached the speed of sound. His research thus revealed a hitherto invisible threshold: the speed of sound, at which air resistance increased greatly. No one could have predicted this phenomenon. Only careful experiment could have revealed it.
Robins’s slim book, New Principles of Gunnery, was translated and emulated. The great Swiss mathematician Leonhard Euler (1707–1783) produced a German edition with the support of the Prussian king Frederick the Great, converting Robins’s hundred fifty pages into more than seven hundred and providing even more complex equations, which took into account such factors as the rate of the gunpowder reaction itself (Robins had postulated an instantaneous expansion of gas) and the effects on barrel pressure of the gas that inevitably blew through the touchhole or past the projectile.49 The result was a set of equations of unprecedented efficacy, which were quickly adopted by artillerists to compute new ballistics tables. Robins in turn responded to Euler’s work, further refining his own, and all over Europe dozens of other scientists, mathematicians, and artillerists built on Robins and Euler’s models: the Irishman Patrick d’Arcy (working for France), the Piedmontese Papacino d’Antoni, the Frenchman Charles de Borda, the Englishman Charles Hutton, the Prussian Georg Friedrich Tempelhoff, the Austrian Georg Vega, and the Frenchman Jean-Louis Lombard, to name a few of the most important.
Their research programs were often sponsored by governments, and the governments were motivated by war. The War of Austrian Succession (1740–1748) stimulated ballistics research in Austria, France, Britain, and, perhaps most notably, the Piedmontese state, whose leader Charles Emanuel III sought advice from Robins himself (Robins advised him to employ low muzzle velocities). During and after the war, the Piedmontese used the ballistic pendulum and other instruments to produce data that led them to develop new guns that optimized muzzle velocity. They also developed a method to estimate muzzle velocity in the field, without instruments: fire projectiles into compacted earth and compare the depths of penetration to the depths produced by a calibrated musket that fired pellets at a known muzzle velocity.
The new ballistics science revolutionized gun design. Artillerists had generally believed that faster projectiles led to greater power. But the new science indicated that air resistance was such an important variable that it made sense in many cases to lower the power of guns, to attain the lowest possible muzzle velocity necessary for one’s objectives. This meant that cannons could be made smaller relative to projectile weight.
Robins himself put the principle into practice. Working with the Royal Navy, he developed a proposal for a new gun with short barrel and thin walls, which would use smaller charges of powder to fire heavy rounds at low velocities. The Royal Navy’s adoption of the carronade in the late eighteenth century was based on these ideas. And the carronade proved enormously useful. A short, light cannon used for close range antiship combat, it was far more destructive than traditional guns of the same size. Moreover, its rate of fire was also higher because its walls were thinner and cooled quickly. In addition, it was light enough to sit on a sliding carriage that absorbed recoil, which meant that it kept its aim after each shot, whereas cannons on traditional carriages had to be wheeled back into place and re-aimed. A carronade also required fewer hands to operate.
The carronade played a major role in the Opium War from the very first battle. In early November 1839, two British sailing vessels were confronted by a Qing fleet of sixteen warjunks and thirteen fireboats guarding the river passage to Canton. HMS Volage carried twenty-six guns, of which at least eighteen were carronades, and HMS Hyacinth carried eighteen guns, of which sixteen were carronades. Taking advantage of the carronades’ quick-fire capacities, they sailed in close and shot devastating broadsides, destroying six junks and throwing the rest into flight, except for the Qing flagship, which the British decided to stop shooting after a good barrage. The Qing ships had guns, but they were older-style cannons. The two British ships sustained little damage.
The carronade played a key role in nearly all subsequent naval battles. For instance, in January 1841 it helped the British capture three fortified islands that guarded the approaches to Guangzhou. The British vessels in the battles carried far more carronades than traditional artillery: the Algerine carried ten guns, of which eight were carronades; the Conway carried twenty-eight guns, of which twenty-six were carronades; the Herald carried twenty-eight guns, of which twenty-six were carronades; and so on. The Qing defenders were overwhelmed by the fast and powerful barrages. It’s not that they lacked cannons; it’s just that theirs were old-fashioned, difficult to aim and fire (although they had managed to obtain one or two carronades). Surveying the guns captured in one fortress, for example, British naval lieutenant John Bingham wrote, “The guns were very long Chinese twelve and twenty-four pounders, with the exception of two carronades, evidently old English ship guns.” He also noted that the gun carriages were primitive: “Their carriages were of the most ordinary description, only a few of them having trucks, the others being merely beds of wood on which the guns rested.” Carronades, able to hurl massive amounts of iron at close range, in rapid succession, and with relatively little powder, were a key armament of the war.
The new ballistics science also underlay the development of new field guns, which, like the carronade, were shorter, thinner-walled, faster, and far more portable than previous models. Small field guns and related guns called howitzers transformed land battles in Europe, and, like the carronade, played key roles in the Opium War. The most striking example—and the saddest—was the Battle of Ningbo in March 1842. The British had captured Ningbo several months before, in October 1841, and the Qing were determined to take it back. After long preparations, the Manchu nobleman Yijing (1793–1853) led thousands upon thousands of Qing troops to attack from two directions at once. They scaled walls and began pouring through gates.
A British force of a hundred men, armed with muskets, four field pieces, and a howitzer, opened fire. “The slaughter,” wrote one British participant, “was quite horrible; the mangled bodies lay in huge piles, heaped one upon another; and old Peninsular officers present declared that, the breach of Badajos alone excepted, they never in a similar small space saw such a mass of slain.” (The Siege of Badajoz of 1812 was one of the bloodiest battles of the Napoleonic Wars.) Another account notes that “the howitzer only discontinued its fire from the impossibility of directing its shot upon a living foe, clear of the writhing and shrieking hecatomb which it had already piled up.” In the Ningbo battles, the British decisively repulsed the most important Chinese offensive in the war, losing only twenty-five men. As Scottish surgeon Duncan MacPherson noted, “the salutary effect produced by the above engagements was very evident, no further molestation being offered to us during our occupation of this city.”
Not only were the new field guns and howitzers powerful. They were also able to be transported by human beings, whereas traditional cannons of equivalent power required teams of horses or oxen. Sometimes the new guns were even pushed on wheelbarrows, “it being easier with these to transport guns over the narrow paths which intersect the paddy grounds, and which present such continual difficulties to the movement of troops through the entire cultivated districts of this country.” In many cases, the British simply made use of China’s excellent roadways. On approaching Nanjing, for example, British lieutenant John Ouchterlony noted, “the road was so broad and straight, that a field-piece could be run along it with ease until within a short distance of the gates.” For cases in which there were no good roads or paths, some pieces, like mountain howitzers, could be disassembled and the parts carried separately.
The evolution of carronades and light field pieces wasn’t of course due to science alone. A multitude of formal and informal experiments played a role, as did new methods of casting and boring. But the new science of ballistics provided the theoretical and mathematical basis, and the Chinese had no equivalent knowledge. They were unprepared for the overwhelming advantage the British had in terms of firepower.
The British also excelled in accuracy, because the new ballistics revolutionized the calculation of trajectories and times to impact. Such calculations were highly technical, requiring trigonometry and calculus, and so in the course of the eighteenth century, European states had increasingly funded military education systems focusing on the mathematics of artillery, such as the Piedmontese Royal Artillery and Military Engineering Academy (established in 1739) and, even more famously, the artillery schools of France.
