She promised, and we drove on for another hour in the direction of a range of hills to the north-eastward.  The lower and nearer portion of this range might he 400 feet above the general level of the plain; beyond, the highest peaks rose to perhaps 1500 feet, the average summit being about half that height.  Where our road brought us to the foot of the first slope, large groves of the calmyra, whose fruit contains a sort of floury pulp like roasted potato, were planted on ground belonging to the State, and tenanted by young men belonging to that minority which, as Esmo had told me not being fortunate enough to find private employment, is thus provided for.  Encountering one of these, he pointed out to us the narrow road which, winding up the slope, afforded means of bringing down in waggons during the two harvest seasons, each of which lasts for about fifty days, the fruit of these groves, which furnishes a principal article of food.  The trees do not reach to a higher level than about 400 feet; and above this we had to ascend on foot by a path winding through meadows, which I at first supposed to be natural.  Eveena, however, quickly undeceived me, pointing out the prevalence of certain plants peculiar to the cultivated pastures we had seen in the plain.  These were so predominant as to leave no reasonable doubt that they had been originally sown by the hand of man, though the irregularity of their arrangement, and the encroachment of one species upon the ground of another, enabled my companion to prove to me with equal clearness that since its first planting the pasture had been entirely neglected.  It was, she thought, worth planting once for all with the most nutritious herbage, but not worth the labour of subsequent close cultivation.  Any lady belonging to a civilised people, and accustomed to a country life, upon Earth might easily have perceived all that Eveena discovered; but considering how seldom the latter had left her home, how few opportunities she had to see anything of practical agriculture, the quickness of her perception and the correctness of her inferences not a little surprised me.  The path we pursued led directly to the object of our visit.  The waters of the higher hills were collected in a vast tank excavated in an extensive plateau at the mid-level.  At the summit of the first ascent we met and were escorted by one of the officials entrusted with the charge of these works, which supply water of extraordinary purity to a population of perhaps a quarter of a million, inhabiting a district of some 10,000 square miles in extent.  The tank was about sixty feet in depth, and perhaps a mile in length, with half that breadth.  Its sides and bottom-were lined with the usual concrete.  Our guide informed me that in many cases tanks were covered with the crystal employed for doors and windows; but in the-pure air of these hills such a precaution was thought unnecessary, as it would have been exceedingly costly.  The water itself was of wonderful purity, so clear that