Great Disaster to Great Opportunity


Franc D. Milient, Portugal, 1785
Print, Paper
National Library of Brazil
Millient, Franc D. “General Map of the City of Lisbon.” 1785. World Digital Library. National Library of Brazil.









This map of Lisbon, created thirty years after the massively disastrous earthquake of 1755 by Franc D. Milient, depicts many of the changes made to Lisbon in the wake of the disaster. Very little is known about Franc D. Milient, aside from his status as a cartographer, but his representation of Lisbon after the completed rebuilding of the Baixa is a priceless diagram illustrating the manner in which the Baixa was rebuilt in the Enlightenment spirit.

The most obvious indication of the new spirit in which the Baixa rose is the grid structure which arranges the buildings into recognizable and extremely regular blocks, reminiscent of a city like Chicago or New York City. This plan, proposed by Eugenio dos Santos, a military engineer under Sebastião José de Carvalho e Melo, the Marqes de Pombal and secretary of state, featured a regular grid meant to evoke the Enlightenment values of symmetry and order. The plan also accounted for the need for practical elements such as easy navigation to and from important locations like the Mint or the trading houses and the safety of those who would live and work there in the future.

Carvalho was the consummate Enlightenment leader. He wanted to use the newest discoveries to create the ideal city center where reason could shine over the rest of the city and Portugal, so he not only consulted his military engineers but asked that a survey be spread throughout the survivors inquiring into their particular experiences and the events of the quake. The survey was the first of its kind, and although modifications have been made as seismology advances, the same basic structure and questions are still used in modern seismology. The answers were used to inform the new design of the Baixa with the intent to make safer the elements that were particularly troublesome during the 1755 earthquake. For example, the grid design, while symbolic of more intangible Enlightenment ideas, was also chosen for its considerations towards safety. The easily navigable streets make it easier to find a way around any street blockages, and the wider streets make it harder to block them in the first place while also preventing secondary damage from buildings falling onto each other across the street.

The architecture of individual buildings was also carefully informed by the new, Enlightenment science along with the survey results. While many changes to the architecture were made, the most important new addition was the gaiola pombalina, a wooden framework of beams in a spoke or cross-like arrangement embedded within the masonry walls of each building. These structures were meant to flex with seismic waves in a way that stone alone would not, and according to modern seismologists it does exactly this, redistributing horizontal seismic forces strikingly well.

Invisible Invaders, Invincible Insects

Plate 9 from Historia Insectorum Generalis
Jan Swammerdam, Netherlands, 1669
Print, Book
Biodiversity Heritage Library; Cornell University Library
Swammerdam, Jan. Tertivs Ordo Nympha. 1669. Cornell University Library. In Historia Insectorum Generalis. Apud Jordanum Luchtmans, 1685. Plate 9. Accessed December 4, 2018.

This plate, depicting the life cycle of ants, is the work of scientist and medical doctor Jan Swammerdam. Swammerdam trained as a medical doctor at the University of Leiden in 1661, and most of his published works reference medical science and especially the question of how breathing functions. This plate is from one of his rare forays into naturalist science publication, although it seems to have been his passion. His father pressured him into concentrating on medical science, hoping that Jan would earn a practical living, but his many friends encouraged him to follow his true interests and one of them even published his Biblia naturae after his death in 1680. The only works he published during his lifetime were a single monograph of a mayfly (which he proceeded to write a hymn to God about) and this text, the Historia Insectorum Generalis.

Swammerdam’s interest in ants was atypical of the era, and for the most part they went unnoticed. While Swammerdam was stationed in the Netherlands, his illustration of the ant life cycle illuminates the reason these tiny, easily-killed individual organisms can and have become massive problems throughout history and in the contemporary world. Ants, typically,  have a reproductive cycle in which there are one or more “queens” who hold the sole ability to lay eggs. These eggs are all fertilized during a single mating flight during a specific mating period usually indicated by environmental conditions such as humidity, food availability, and—in some areas—whether the nest has been flooded recently. Ant-keepers often encourage increases in their colony size by introducing more food, which stimulates colony growth along with possible mating nymph production. After this mating flight, the queen lands, finds a suitable area to form a nest, and loses her wings. From this single queen, every ant in the colony will be laid and hatched.

This ability to essentially create a colony of several thousand (or more) ants is what makes ants such a potent environmental agent, especially during a time such as the age of the Columbian Exchange when new stimuli were introduced to new countries. While people like Swammerdam showed rare interest in insects and ants in particular, most individuals during the early modern period failed to notice insects at all. One particularly stunning example of ants going unnoticed, despite massive indications of their role in a disaster, took place in Hispaniola in 1518. The Spanish colonists in Hispaniola brought plantain trees from Africa to populate the plantations on the island and probably to help diversify the crops they could sell aside from sugar. Hiding away on these trees, however, was a plague that only became dangerous when introduced to the ecological system of Hispaniola: mealybugs.

When these mealybugs were introduced to Hispaniola, they were also introduced to an army of new friends: fire ants, or Solenopsis geminata. S. geminata is well-known to “herd” or “farm” mealybugs, even “milking” them for the sweet, calorie-rich waste product they excrete called “honeydew”. This new, massive availability of food led to an explosion of ant population, so much so that colonists had to put the legs of their beds in bowls of water to prevent ants stinging them in their sleep as their floors were carpeted with thousands of ants. The plantations withered, but the colonists did not attribute this to the proper invaders; rather, they blamed the ants. The colonists had no care for the mechanisms of ants or how they really functioned. That was unique to people like Jan Swammerdam, with passions that led us to our current understanding of science and specifically modern entomology.