The gray of the uniforms worn by both officers and men helped this air of mystery. Only the sharpest eye could detect among the thousands that passed the slightest difference. All moved under a cloak of in visibility. Only after the most numerous and severe tests, with all materials and combinations of color that give forth no color, could this gray have been discovered. That it was selected to clothe and disguise the German when he fights is typical of the German Staff in striving for efficiency to leave nothing to chance, to neglect no detail. 
After you have seen this service uniform under conditions entirely opposite you are convinced that for the German soldier it is his strongest weapon. Even the most expert marksman cannot hit the target unless he can see. It is a gray-green, not the blue-gray of our Confederates. It is the gray of the hour just before daybreak, the gray of unpolished steel, of mist among green trees. 
I saw it first in the Grand Place in front of the Hotel de Ville. It was impossible to tell if in that noble square there was a regiment or a brigade. You saw only a fog that melted into the stones, blended with the ancient house fronts, that shifted and drifted, but left you nothing at which you could point. 
Later, as the army passed below my window, under the trees of the Botanical Park, it merged and was lost against the green leaves. It is no exaggeration to say that at a hundred yards you can see the horses on which the Uhlans ride, but cannot see the men who ride them. If I appear to overemphasize this disguising uniform it is because of all the details of the German out fit it appealed to me as one of the most remarkable. The other day, when I was with the rear guard of the French Dragoons and Cuirassiers and they threw out pickets, we could distinguish them against the yellow wheat or green gorse at half a mile, while these men passing in the street, when they have reached the next crossing, become merged into the gray of the paving stones and the earth swallows them. In comparison the yellow khaki of our own American Army is about as invisible as the flag of Spain.
Yesterday Major General von Jarotsky, the German Military Governor of Brussels, assured Burgomaster Max that the German army would not occupy the city, but would pass through it. It is still passing. I have followed in campaigns six armies, but excepting not even our own, the Japanese or the British, 1 have not seen one so thoroughly equipped. I am not speaking of the fighting qualities of any army, only of the equipment and organization. The German army moved into this city as smoothly and as compactly as an Empire State Express. There were no halts, no open place, no stragglers. 
This army has been on active service three weeks, and so far there is not apparently a chin-strap or a horseshoe missing. It came in with the smoke pouring from cookstoves on wheels, and in an hour had set up post office wagons, from which mounted messengers galloped along the line of column distributing letters and at which soldiers posted picture post-cards. 
The infantry came in in files of five, two hundred men to each company; the lancers in columns of four, with not a pennant missing. The quick-firing guns and field pieces were one hour at a time in passing, each gun with its caisson and ammunition wagon taking twenty seconds in which to pass. 
The men of the infantry sang "Fatherland, My Fatherland." Between each line of song they took three steps. At times two thousand men were singing together in absolute rhythm and beat. When the, melody gave way the silence was broken only by the stamp of ironshod boots, and then again the song rose. When the singing ceased the bands played marches. They were followed by the rumbles of siege guns, the creaking of wheels and of chains clanking against the cobble-stones and the sharp bell-like voices of the bugles.
For seven hours the army passed in such solid column that not once might a taxicab or trolley car pass through the city. Like a river of steel it flowed, gray and ghostlike. Then, as dusk came and a thousands of horses' hoofs and thousands of iron boots continued to tramp forward, they struck tiny sparks from the stones, but the horses and men who beat out the sparks were invisible. 
At midnight pack wagons and siege guns were still passing. At seven this morning I was awakened by the tramp of men and bands playing jauntily. Whether they marched all day or not I do not know; but for twenty six hours the gray army rumbled with the mystery of fog and the pertinacity of a steam roller.