and we dared not dodge the bursts, however close, as area
photography from anything but an even line of flight is useless. Yet,
though the bursts kept us on edge, we were not touched by so much as a
splinter. In this we were lucky under the conditions. The luck could
scarcely have held had the job lasted much longer than a quarter of an
hour--which is a consoling thought when one is safe back and writing to
a dear friend in England, not?

Northward, along the left-hand side of the road, was my first subject;
and a damned unpleasant subject it was--a dirty-soiled, shell-scarred
wilderness. I looked overboard to make certain of the map square,
withdrew back into the office, pulled the shutter-string, and loaded the
next plate for exposure.

"_Wouff!_ _Ouff!_ _Ouff!_" barked Archie, many times and loud. An
instinct to swerve assaulted the pilot, but after a slight deviation he
controlled his impulse and held the bus above the roadside. He had a
difficult task to maintain a level course. Whereas we wanted to make
east-north-east, the wind was due east, so that it cut across and
drifted us in a transverse direction. To keep straight it was necessary
to steer crooked--that is to say, head three-quarters into the wind to
counteract the drift, the line of flight thus forming an angle of about
12 deg. with the longitudinal axis of the aeroplane.

"_Wouff!_ _ouff!_" Archibald continued, as I counted in seconds the
interval to the scene of the next snapshot, which, as assurance that the
whole ground would be covered, was to overlap slightly the first. A
quick glance below, another tug at the string, and plate the second was
etched with information. The third, fourth, and fifth followed; and
finally, to our great relief, we reach Le Sars.

Here the pilot was able to dodge for a few seconds while we turned to
retrace the course, this time along the southern edge of the road. He
side-slipped the bus, pulled it around in an Immelmann turn, and then
felt the rudder-controls until we were in the required direction. The
interval between successive exposures was now shorter, as the east wind
brought our ground speed to 120 miles an hour, even with the engine
throttled back. There was scarcely time to sight the objective before
the photograph must be taken and the next plate loaded into place.
Within two minutes we were again over Pozieres.

V. took us across the lines, so as to deceive the Archie merchants into
a belief that we were