If the printed book was the most "admirable" innovation of the fifteenth century, the firearm, now reaching maturity after a slow start, was the most dramatic. Erratic black powder was tamed to consistency by the invention in the 1420s of "corning," or granulation, by which the powder, dampened by vinegar, brandy, or "the urine of a wine-drinking man," was passed through a sieve, forming coarse granules, not only safer to handle but more reliable in action. Experimentation with mixtures improved explosive power, and consequently range and accuracy. Gradually the weight of the projectile diminished in proportion to the weight of the gun, and the weight of powder rose replaced by the slow match, a cord soaked in niter and alcohol. ...
Similarly, gunpowder artillery crossed a threshold. Fabrication was made easier by a new technique, casting a mold to form a hollow cylinder around a mandrel (core); using the same mold guaranteed identical calibers. In the closing stage of the Hundred Years War, the royal French artillery under the command of the Bureau brothers, a pair of talented smiths, used iron cannonballs to batter down one English-held castle and town wall after another and even performed effectively in the field, as at Castillon, the war's last battle, in 1453.
Gunpowder weapons had three conspicuous effects. First, artillery reinforced the trend toward the national professional army, since only a wealthy central government could afford it. Sovereigns often took a personal interest in their martial toys; John II of Portugal and Emperor Maximilian of Germany were two who expressed not only enthusiasm for but genuine expertise in the "art of gunnery."Frances & Joseph Gies; Catherdral, Forge and Waterwheel, pp. 247-252
Second, small arms made the armored knight obsolete, not so much because his armor did not stop musket balls as because the new musket infantry was cheaper to arm and equip and more flexible to employ, and the emerging pistol-armed cavalry of the sixteenth century much more formidable. Breastplates and helmets continued in fashion through the seventeenth century, but chain mail and full armor disappeared except for parades and tournaments. Individual prowess, hallmark of the age of chivalry, was curtailed as the new-model army extended the principle of standardization from arms and ammunition to uniforms and drill.
Third, the curtain-walled castle was superseded by the low-profile, thick rampart fortress, capable of absorbing the shock of heavy cannonballs and furnishing a good platform for defensive artillery but ill adapted to service as a private residence. The new style fortifications mostly supplanted old-fashioned city walls and were manned by garrisons belonging to the central government. The aging castles of the feudal nobility sank to the status of not very comfortable country houses, storage depots for gunpowder and cannonballs, or prisons for distinguished captives.
Joseph Needham points to China's influence in the large social changes at both ends of the European Middle Ages: "Thus one can conclude that just as Chinese gunpowder helped to shatter this form of society at the end of the period, so Chinese stirrups had originally helped to set it up." Neither invention had any perceptible impact on Chinese society, owing, in Needham's interpretation, to its relative stability compared with Western society.
However that may be, the origins of feudalism in Europe involved much more than stirrup, horseshoe, and saddle, and, by the same token, feudalism was already in decline when gunpowder gave it a final push toward the grave by benefiting national governments at the expense of the old castle-building, armor-wearing, horseback-riding feudal aristocracy.
A subtler effect of the new weaponry and fortifications was their impact on the incipient engineering profession. Expertise was suddenly in great demand. In response, technical treatises began to appear. The first important It one came from southern Germany, where metal mining contributed to the growth of an arms industry. The Bellifortis (Strong war) of Konrad Kyeser of Eichstadt (1366-after 1405) remained a bible for military leaders for more than a century. Kyeser has been called "the first great engineer who has left us a well-established technological oeuvre" (Bertrand Gille).
A physician by profession, Kyeser published his work at the beginning of the fifteenth century, when the gunpowder age was still new. Among his sketches are a battery of cannon mounted on a turntable to be fired in succession, an artillery-carrying chariot, and a long-barreled, small-bore culverin resting on a stand. But of an array of proposed war chariots armed with pikes, lances, scythes, and hooks, only two carry rudimentary cannon, and the incendiary projectiles Kyeser sketched were ammunition not for guns but for crossbows.
Knights-errant had ridden into the sunset. In their place were professional soldiers, who "followed their mercenary calling / And took their wages and are dead."
At the exact moment that the glass lens was allowing us to extend our vision to the stars or microscopic cells, glass mirrors were allowing us to see ourselves for the first time. It set in motion a reorientation of society that was more subtle, but no less transformative, than the reorientation of our place in the universe that the telescope engendered. "The most powerful prince in the world created a vast hall of mirrors, and the mirror spread from one room to another in the bourgeois household," Lewis Mumford writes in his Technics and Civilization. "Self-consciousness, introspection, mirror-conversation developed with the new object itself" Social conventions as well as property rights and other legal customs began to revolve around the individual rather than the older, more collective units: the family, the tribe, the city, the kingdom. People began writing about their interior lives with far more scrutiny. ..Steven Johnson, How We Got to Now, pp. 34-37
How much does this transformation owe to glass? Two things are undeniable: the mirror played a direct role in allowing artists to paint themselves and invent perspective as a formal device; and shortly thereafter a fundamental shift occurred in the consciousness of Europeans that oriented them around the self in a new way, a shift that would ripple across the world (and that is still rippling). No doubt many forces converged to make this shift possible: the self-centered world played well with the early forms of modern capitalism that were thriving in places like Venice and Holland (home to those masters of painterly introspection, Durer and Rembrandt). Likely, these various forces complemented each other: glass mirrors were among the first high-tech furnishings for the home, and once we began gazing into those mirrors, we began to see ourselves differently, in ways that encouraged the market systems that would then happily sell us more mirrors. It's not that the mirror made the Renaissance, exactly, but that it got caught up in a positive feedback loop with other social forces, and its unusual capacity to reflect light strengthened those forces. ..
[The historian Alan] McFarlane has an artful way of describing this kind of causal relationship. The mirror doesn't "force" the Renaissance to happen; it "allows" it to happen. ..Without a technology that enabled humans to see a clear reflection of reality, including their own faces, the particular constellation of ideas in art and philosophy and politics that we call the Renaissance would have had a much more difficult time coming into being. Yet the mirror was not exclusively dictating the terms of the European revolution in the sense of self. A different culture, inventing the fine glass mirror at a different point in its historical development, might not have experienced the same intellectual revolution, because the rest of its social order differed from that of fifteenth-century Italian hill-towns. The Renaissance also benefited from a patronage system that enabled its artists and scientists to spend their days playing with mirrors instead of, say, foraging tor nuts and berries. A Renaissance without the Medici—not the individual family, of course, but the economic class they represent—is as hard to imagine as the Renaissance without the mirror.
It should probably be said that the virtues of the society of the self are entirely debatable. Orienting laws around individuals led directly to an entire tradition of human rights and the prominence of individual liberty in legal codes. That has to count as progress. But reasonable people disagree about whether we have now tipped the scales too far in the direction of individualism, away from those collective organizations: the union, the community, the state. Resolving those disagreements requires a different set of arguments—and values—than the ones we need to explain where those disagreements came from. The mirror helped invent the modern self, in some real but unquantifiable way. That much we should agree on. Whether that was a good thing in the end is a separate question, one that may never be settled conclusively.