Ross had little time to notice the work of destruction. His particular business was to observe the fire directed upon a large redoubt to the north-east of the town. The first shell from the monitor fell short, blowing an enormous crater in the grass-grown dunes. The second fell beyond, completely demolishing a house. The third dropped fairly in the centre of the redoubt, causing a terrific explosion that was not due solely to the lyddite bursting-charge. The magazine had exploded.
Skywards rushed an enormous cloud of black and yellow smoke. Caught by the blast of the violently displaced air the sea-plane rocked, then began dropping like a stone.
For the moment Ross imagined that the end had come. He was no longer afraid. A sensation of intense curiosity as to what the machine and its occupants would look like seemed to obsess his mind.
Then, with a jerk that reminded the midshipman of the sudden starting of a lift, the sea-plane "flattened out" and began to climb out of the enveloping cloud of smoke.
The Flight-Sub turned his head and grinned broadly. His manner could not do otherwise than inspire confidence. Although not a pilot, he was master of the frail machine. Side-slips and nose-dives troubled him but little, provided he was flying at a safe altitude.
"A jolly good wipe-out!" he exclaimed. "There won't be many Bosches left within half a mile of that battery, I'm thinking. Now watch when the next shot lands: that will give you the objective."
A sharp buzzing in the receiver attached to Ross's flying helmet announced that the monitor was "calling up" her observer. Quickly the lad seized the pencil, and gave the signal that he was ready to take down the message.
The Morse signal, when translated into writing, was as follows:—
"Register Position 47."
"Good!" exclaimed the Plight-Sub when Ross had telephoned him the message. He consulted his map, which was similar to the one at the observer's disposal "Position 47: that's a railway junction."