They shall go from West to East during the first year, and back from East to West during the second.

Thus they will gain a perfect knowledge of the country at every season of the year.
While on service, their first duty will be to see that the country is well protected by means of fortifications and entrenchments; they will use the beasts of burden and the labourers whom they find on the spot, taking care however not to interfere with the regular course of agriculture.

But while they thus render the country as inaccessible as possible to enemies, they will also make it as accessible as possible to friends by constructing and maintaining good roads.

They will restrain and preserve the rain which comes down from heaven, making the barren places fertile, and the wet places dry.

They will ornament the fountains with plantations and buildings, and provide water for irrigation at all seasons of the year.