Further, he describes a method discovered by Thales of Miletus for ascertaining the pyramid's height by measuring its shadow.[61]

Late antiquity and the Middle Ages
Further information: Joseph's Granaries
During late antiquity, a misinterpretation of the pyramids as "Joseph's granary" began to gain in popularity. The first textual evidence of this connection is found in the travel narratives of the female Christian pilgrim Egeria, who records that on her visit between 381 and 384 AD, "in the twelve-mile stretch between Memphis and Babylonia [= Old Cairo] are many pyramids, which Joseph made in order to store corn."[62] Ten years later the usage is confirmed in the anonymous travelogue of seven monks that set out from Jerusalem to visit the famous ascetics in Egypt, wherein they report that they "saw Joseph's granaries, where he stored grain in biblical times."[63]
This late 4th century usage is further confirmed in the geographical treatise Cosmographia, written by Julius Honorius around 376 AD,[64] which explains that the Pyramids were called the "granaries of Joseph" (horrea Ioseph).[65] This reference from Julius is important, as it indicates that the identification was starting to spread out from pilgrim's travelogues. 