Now the secret was out! What we actually saw was this: not a single wide canal but a series of comparatively narrow canals, running parallel to each other, with a very wide strip of vegetation between each. Usually the canals were linked together in pairs by smaller cross canals running diagonally from one canal to the other in alternate order. These were the irrigation trenches. Thus from one of a pair of canals an irrigation trench would branch out at an angle of about fifty degrees, and enter the second canal. Higher up, on the same side, another trench would run from the second canal at a similar angle, and enter the first canal, and so on--_ad infinitum_. In the case of single canals curved loops branched out and re-entered higher up, these loops being made on either side, and similar loops were made on the outsides of paired canals. As a result of this arrangement it did not matter whether the water passed up the canal at one season of the year or down it at another season, it could always move straight ahead; the irrigation trenches were thus constantly flushed by one or other of the pairs, and there could be no stagnation anywhere. Merna also told us that some canals are provided with a network of trenches, whilst others are embanked so that the water can be let out through sluices when necessary, and thus flood the surrounding land. Thus every requirement can be met. So far from being a hundred miles wide, it was exceptional for the canals to have a width of more than two hundred yards. Most of those we were looking at were only about sixty feet wide! and only the wider ones are used for navigation purposes. Merna explained why this was so, saying that as the main use of the canals was for irrigation purposes very wide ones were not required; for not only would they be wasteful, but as it was necessary to force the water along by artificial means, it could more conveniently be accomplished in the case of narrow canals, as the wider the canal the more difficult it became to force the water along. We also observed many splendid wide motor-roads running between the single canals, as well as others running straight across the system, being carried over the canals by the most beautiful and fairy-like bridges that we had ever seen. They were all constructed of a metal identical with our "martalium," which we had used in the construction of the _Areonal_; so that was undoubtedly another invention which we owed to Martian influences transmitted to us across space! Nothing more beautiful or graceful than these bridges could be imagined, so light were they in construction, so elegant and varied in design, and every part shining in the sun like burnished silver; they looked like structures composed of rays of light rather than substantial metal! They were a perfect dream of beauty, and we stood a long time examining their elegant construction through our glasses.