rth. It
was a depressing dawn--clammy, moist, and sticky.

But by early afternoon the mist had congealed, and the sheet of clouds
was torn to rags by a strong south-west wind. The four craft detailed
for the reconnaissance were therefore lined outside their shed, while
their crews waited for flying orders. I was to be in the leading bus,
for when C.'s death left vacant the command of A Flight, the good work
of my pilot had brought him a flight-commandership, a three-pipped
tunic, and a sense of responsibility which, to my relief, checked his
tendency to over-recklessness. He now came from the squadron office with
news of a changed course.

"To get the wind behind us," he explained, "we shall cross well to the
south of Peronne. Next, we go to Boislens. After that we pass by
Nimporte, over the Foret de Charbon to Siegecourt; then up to Le Recul
and back by Princebourg, St. Guillaume, and Toutpres.

"As regards the observers, don't forget to use your field-glasses on the
rolling stock; don't forget the precise direction of trains and motor
transport; don't forget the railways and roads on every side; don't
forget the canals; and for the Lord's and everybody else's sake, don't
be surprised by Hun aircraft. As regards the pilots--keep in close
formation when possible; don't straggle and don't climb above the proper
height."

The pilots ran their engines once more, and the observers exchanged
information about items such as Hun aerodromes and the number of railway
stations at each large town. An air reconnaissance is essentially the
observer's show; its main object being to supply the "I" people at
headquarters with private bulletins from the back of the German front.
The collection of reconnaissance reports is work of a highly skilled
nature, or ought to be. Spying out the land is much more than a search
of railways, roads, and the terrain generally. The experienced observer
must know the German area over which he works rather better than he
knows Salisbury Plain. The approximate position of railway junctions and
stations, aerodromes, factories, and depots should be familiar to him,
so that he can without difficulty spot any new feature. Also he must be
something of a sleuth, particularly when using smoke as a clue. In the
early morning a thin layer of smoke above a wood may mean a bivouac. If
it be but a few miles behind the lines, it can evidence heavy artillery.
A narrow stream of smoke near a railway will make an obs