With Vimy Ridge in the possession of the Germans, their access for observation placed us at a decided disadvantage; the Lens-Arras, the Mont St. Eloi road--all vital feeding routes for our system--were absolutely open to his inspection at all hours of the day or night; there was no movement along these channels of communication of either men, guns, ammunition, supplies of any kind, of which they were not fully cognizant. So it will be seen that the possession of this elevation was of wonderful advantage to the side holding it. One of the chief gains to be derived from its possession was the control of the vast coal mines of Lens, one of the richest coal producing sections in France, and the benefit of which has been in German hands since the gray rush first went through. And the possession of the output of these mines gave Fritz a priceless advantage over us. His overlooking position also made it impossible for us to work in the daytime the few coal mines that we had; neither could we supply our guns with the necessary ammunition during the hours of daylight; and further, the possession of this vantage point would release for duty elsewhere a tremendous number of men whose presence there was unavoidable, because of the control he had over the valley and the surrounding country. So, when the chief command decided to take the ridge, they went about the job in a manner thoroughly characteristic of the Scotch commander, Sir Douglas Haig, and his thoroughness was well borne out by the results. For the space of a month prior to the drive, every hour of the darkness was used to get guns, ammunition and supplies into place; all night long the traffic on the roads was so congested that going faster than a walk with any conveyance, over any part of the channels of communication, was simply out of the question; but when day broke it was imperative that not a single conveyance of any kind be in sight on any road. Do not imagine, however, that we were free to work as long as the shelter of night lasted; in the artificial light furnished by the flares, Fritz did a lot of damage. On one single night during this work of preparation on the Mont St. Eloi road alone, 156 horses were killed; and on all through roads, each night that the stage was being set for the production of the first scene, casualties were had with deadly regularity.