32 A HISTORY OF EGYPT
and the emblem of Neit, its chief goddess was tattooed by the Libyans upon their arms. It may possibly therefore have been an early residence of a Libyan king of the Delta, although the capital of the Northern Kingdom was traditionally Buto, which, we may conjecture, owed this distinction to the later predominance of Egyptian influence, Sais being too extremely Libyan to be retained as the seat of government. As its coat of arms or symbol the Northern Kingdom employed a tuft of papyrus plant, which grew so plentifully in its marshes as to be distinctive of it. The king himself was designated by a bee, and wore upon his head a red crown, both in colour and shape peculiar to his kingdom. All of these symbols are very common in later hieroglyphic. Red was the distinctive colour of the northern kingdom and its treasury was called the "Red House."
Unfortunately the Delta is so deeply overlaid with deposits of Nile mud, that the material remains of its earliest civilization are buried forever from our reach. That civilization was probably earlier and more advanced than that of the valley above. Already in the forty third century B. C. the men of the Delta had discovered the year of three hundred and sixty five days and they introduced a calendar year of this length beginning on the day when Sirius rose at sunrise, as determined in the latitude of the southern Delta, where these earliest astronomers lived, in 4241 B. C. It is the civilization of the Delta, therefore, which furnishes us with the earliest fixed date in the history of the world. The invention and introduction of this calendar is surprising evidence of the advanced culture of the age and locality to which it belongs. No nation of antiquity, from the earliest times through classic European history, was able to devise a calendar which should evade the inconvenience resulting from the fact that the lunar month and the solar year are incommensurable quantities, the lunar months being inconstant and also not evenly dividing the solar year. This earliest known calendar, with an amazingly practical insight into the needs to be subserved by a calendar, abandoned the