Explore the Mass Incubators of Ancient Egypt

Thousands of years ago, Egyptians artificially incubated eggs by building two-story brick incubators and lighting fires above them.

Today, farmed chicks are almost never hatched by their mothers. Instead, they are hatched artificially in large electric furnaces called incubators , devices that can hold hundreds or even thousands of eggs at a time. Electric incubators are a modern invention, but artificial incubation has been around for thousands of years.

Illustration of an incubator in ancient Egypt. (Photo: Amusing Planet).

The ancient Egyptians were the first to use poultry incubators . They impressed foreign visitors who had never seen anything like it.

Many travelers left cryptic notes about the strange method the Egyptians used to hatch chicks. Because they were rarely given detailed explanations of how the incubators worked, they were left to guess and were often wrong.

One writer claimed that the Egyptians sat on eggs and incubated them. The monk Simon Fitzsimons, who visited Egypt in the 14th century, wrote that chickens were born from eggs by fire, without the need for a rooster or hen. He did not know that the eggs were fertilized in the traditional way by a rooster before being placed in an incubator. Even the Greek philosopher Aristotle wrote about incubators, suggesting that eggs were buried in dung heaps, around the 4th century BC.

The first widely read travelogue to include a somewhat realistic description of an Egyptian incubator was The Travels of Sir John Mandeville , published in 1356. "There is a common building in the city filled with small ovens, and the women of the city bring eggs from hens, geese, and ducks to put into the ovens. The caretakers of the building cover the eggs with the heat of horse dung, without hens, geese, ducks, or any other poultry. After three weeks or a month the women return to take the chicks and feed them, so that the whole district is full of poultry ," Mandeville wrote.

French naturalist and scientist René Antoine Ferchault de Réaumur provided the first accurate description of incubators in 1750. Réaumur traveled to Egypt and visited many incubators, observing farmers at work.

The typical Egyptian incubator was a brick structure about 3m high, consisting of a long central corridor with rooms on either side, arranged in two levels. The two levels were of equal size, with an entrance large enough for a person to crawl inside. The eggs were placed on the ground floor, on bedding made of flax or straw. The rooms above were used to light fires, using cow and camel dung mixed with straw. This allowed the fire to burn more slowly and in a more controlled manner.

The keepers usually light fires twice a day, depending on the weather, and turn the eggs so that they are evenly heated from all sides. This continues for about two weeks, after which the fires are extinguished. By this time, the organs in the embryos have fully developed and are generating enough heat to continue the incubation process, which takes another week to complete. The eggs finally hatch on the 21st day.

Returning to France, Réaumur attempted to build an incubator using the Egyptian method, but due to the cooler European climate, he was not as successful as the Egyptian farmers. After Réaumur's death, the incubator was further developed by Abbé Jean-Antoine Nollet, then by Abbé Copineau, who improved on Réaumur's design by using alcohol lamps to heat the eggs. It was not until the late 19th century that the first commercial incubator appeared.

A traditional Egyptian incubator uses oil lamps to warm eggs. (Photo: Lenny Hogerwerf/Atlas Obscura).

In 21st century Egypt, hundreds of incubators still use traditional methods developed thousands of years ago, although manure has been replaced by oil lamps and electric heaters. Farmers still do not use modern equipment such as thermometers or thermostats to regulate the temperature in the incubator.

Skilled incubators can judge the temperature by holding an egg to their eyelids and letting their eyes feel the heat. If it is too hot, the egg is sprayed with water. To check the development of an egg, the incubator simply holds the egg up to a light source such as a lamp. The shell is thin enough to allow them to see inside. These skills are passed down from generation to generation in some families and kept secret from the outside world.

However, Egypt's traditional incubators may soon disappear. According to a 2009 survey conducted by the Food and Agriculture Organization of the United Nations, all incubator owners surveyed expressed a desire to upgrade to modern incubation methods due to higher hatching rates.