Located about nineteen miles south of modern-day Cairo, Saqqara encloses the pyramids of seventeen kings --- most famously, Djoser's step pyramid --- in a one-by-four-mile area additionally populated by the numerous funeral monuments of high officials. As some indication of the massive expanse of the necropolis and its sustained use across the millennia, an international team of researchers in 2011 uncovered almost eight million animal mummies there. Accordingly, Saqqara was the focus of major construction efforts requiring extensive labor energies from the earliest dynasties over many centuries. How did the Serapeum fit into such a busy city of the dead?

In light of high technological skills exhibited by the Ancient Egyptians, a plausible answer was provided in 2018 by Konstantin Borisov, a Ph.D. in Electrical Engineering from Mississippi State University. 8 Because they had already mastered fermentation processes for brewing alcoholic beverages and making eatable starches by their 1st Dynasty, he suggested they closed bread, beer, barley and ox meat inside the Serapeum's stone coffers. As fermentation set in, yeast began to convert the starch presence in barley to CO2 gas and ethanol. Essential for yeast to grow and maintain its developing rate over time was eleic acid present in the ox meat. Eleic acid also negated the toxic effects of ethanol, a by-product of the fermentation process.

Continuous accumulation of confined CO2 gas steadily raised pressure inside the box, which was made to withstand more than sixty thousand PSI, before its thirty-ton lid could be dislodged. Since tolerance between the cover and the rim of the box on which it rested was within one micron, the receptacle was effectively sealed hermetically, preventing any gas from seeping out, and ensuring the accrual of pressure. Resistance could be increased for building higher pressures by piling additional weight atop the lid, itself designed with a raised, reinforced platform for accommodating heavy loads. Six courses of stones were, in fact, originally layered on top of at least one lidded chest, as observed by Auguste Mariette, a French archaeologist who discovered the Serapeum in 1851.

He was also the first researcher to investigate its boxes, all of them empty, save one containing the mummy of Khaemweset, a king who restored the underground complex around 1220 B.C., and another filled, not with ceremoniously mummified bulls, but its floor indiscriminately scattered with ox bones; these alone of all other ingredients and their by-products would not have been consumed by the yeast. Pharaonic sarcophagi were made to fit the form of the deceased from local limestone, far more ready at hand and much less difficult to work than the Serapeum's untypically oversized coffers of granite and even harder diorite, transported --- at what must have been extraordinary difficulty --- from quarries five hundred and seven hundred miles away. Rose granite and diorite were deliberately chosen, not only because they were supremely strong and dense enough to contain thirty tons of pressure and prevent gas from seeping through their pores, but for their high density crystalline structure.

Piezoelectricity is an electric charge that accumulates in crystals responding to applied mechanical stress. Fermentation inside the Serapeum's chests exerted pressure on their crystalline enclosure to generate piezoelectric discharges. Notches cut into the close-fitting chambers containing the boxes are precisely parallel to the edges of each lid, allowing the covers to be rotated on the rims of the coffers, thereby exposing their interior for periodic maintenance; i.e., scrubbing out residue from used up ingredients and replacing them with fresh bread, beer, barley and ox meat. Although French physicists Jacques and Pierre Curie are credited with the discovery of piezoelectricity in 1880, their find was preceded, according to Borisov, by ancient electrical engineers, who buried two dozen, massive, static-charge batteries connected in series at Saqqara, thousands of years ago.

No place throughout the Nile Valley was more in need of such a power supply for the numerous machining tools, as described by Christopher Dunn, that built and fashioned so large a concentration of pyramids and funeral monuments at Egypt's foremost city of the dead. Walls and ceilings of royal or aristocratic burial sites there were invariably covered with lengthy, hieroglyphic quotations from the Book of the Dead or other, sacred texts, illustrated by paintings or sculpted bas relief, surrounding collected grave goods, statuary and richly decorated sarcophagi. By sharp contrast, the Serapeum's barren, rough-hewn corridors show neither polishing nor finishing.

There are no images of men or gods, no decoration of any kind, and its scanty hieroglyphs are uncommonly poor quality, obviously added by someone centuries after the site was constructed. In short, it less resembles a ceremonial mortuary, than a purely functional utility. And that was the Serapeum's original identity. Its eighteen hundred years of oblivion beneath the desert sands suggest comparable power stations await their discovery at other dynastic urban centers, where evidence of monumental machining is being recognized. Skeptics argue that Borisov's characterization of the Serapeum's granite boxes as piezoelectric batteries are unlike any electric generators with which we are familiar.

"When we try to envision past energy systems," Dunn points out, "we have many layers of cultural blinders to see through. As we search through the remnants of ancient Egypt looking for the power plants that provided energy to the machine tools that accurate shaped the granite blocks on the Giza Plateau, or the granite boxes in the rock tunnels at Saqqara, we cannot assume that their power plants looked like ours, or that the infrastructure supporting the distribution of energy was the same. Considering the extremely tenuous circumstances by which inventions are developed, promoted and utilized, it would be very surprising to find an ancient artifact, or evidence of an artifact, that is identical to one we use or have used in the recent past." 9