Presently, as we sat there, we heard--above the rumbling of cannon wheels, the nimble clunking of hurrying hoofs and the heavy thudding of booted feet, falling and rising all in unison--a new note from overhead, a combination of whir and flutter and whine. We looked aloft. Directly above the troops, flying as straight for Brussels as a homing bee for the hive, went a military monoplane, serving as courier and spy for the crawling columns below it. Directly, having gone far ahead, it came speeding back, along a lower air lane and performed a series of circling and darting gyrations, which doubtlessly had a signal-code meaning for the troops. Twice or three times it swung directly above our heads, and at the height at which it now evoluted we could plainly distinguish the downward curve of its wing-planes and the peculiar droop of the rudder--both things that marked it for an army model. We could also make out the black cross painted on its belly as a further distinguishing mark. To me a monoplane always suggests a bird when it does not suggest an insect or a winged reptile; and this monoplane particularly suggested the bird type. The simile which occurred to me was that of the bird which guards the African rhinoceros; after that it was doubly easy to conceive of this army as a rhinoceros, having all the brute strength and brute force which are a part of that creature, and its well-armored sides and massive legs and deadly horned head; and finally its peculiar fancy for charging straight at its objective target, trampling down all obstacles in the way. The Germans also fancy their monoplane as a bird; but they call it _Taube_--a dove. To think of calling this sinister adjunct of warfare a dove, which among modern peoples has always symbolized peace, seemed a most terrible bit of sarcasm. As an exquisite essence of irony I saw but one thing during our week-end in Louvain to match it, and that was a big van requisitioned from a Cologne florist's shop to use in a baggage train. It bore on its sides advertisements of potted plants and floral pieces--and it was loaded to its top with spare ammunition. Yet, on second thought, I do not believe the Prussians call their war monoplane a dove by way of satire. The Prussians are a serious-minded race and never more serious than when they make war, as all the world now knows. Three monoplanes buzzed over us, making sawmill sounds, during the next hour or two. Thereafter, whenever we saw German troops on the march through a country new to them we looked aloft for the thing with the droopy wings and the black cross on its yellow abdomen. Sooner or later it appeared, coming always out of nowhere and vanishing always into space. We were never disappointed. It is only the man who expects the German army to forget something needful or necessary who is disappointed.