Page:Travels to Discover the Source of the Nile - In the Years 1768, 1769, 1770, 1771, 1772, and 1773 volume 3.djvu/703

 THE SOURCE OF THE NILE. 679

It is fcarcely necefTary to obferve, that, in every ftate or fociety, the product or revenue fhould be known, as well as what will be wanted for the fupply of the neceffities of the people. Now, it was only the ground overflowed by the Nile that could produce grain for the fubfiftence of the in- habitants and revenue of the ftate.

The firft confideration, then, was, to know how much of the land of i ( gypt was overflowed in a given term of years, and how much grain was produced upon that average. This could only be afcertained by meafuring, and they, therefore, fettled with precifion the land that was overflow- ed from the earlieft times, and do fo to this day. Thefe actual meafurements gave them a ?naximum and a mini- mum, which furnifhed them with a mean, and thus they were in pofTeflion of all the principles necefTary for making aNilometer, by dividing a pillar into correfponding cubits, and divifions of cubits called digits, placing it alfo firm and perpendicular, fo as to be liable to no alteration or injury,, though in the middle of the ftream.

The firft ftated meafure was certainly that mentioned in fcripture, the cubit, fecundum cubitum vlrilis mantis, meafur- ing from the center of the round bone in the elbow to the point of the middle finger*. This is Hill the meafure of all unpolifhed nations, but no medium or term, expreffive of its exact contents, having been applied, writers have dif- fered as to the length of this cubit, and no flandard exifting to which it might be referred, a great deal of confu-

fion

f Deut. chap. ili. tm. II.