y on
to the water about midway between Selsey Bill and the Isle of Wight.
Then the _Flying Fish_ folded her wings and sank to a depth of twenty
feet. Then, at a speed of ten knots, she worked her way in a zigzag
course back and forth across the narrowing waters, up the channel
towards Portsmouth.

To his surprise, the needle remained steady, showing that there was
neither submarine nor torpedo boat near. This meant, as far as he could
see, that the main approach to the greatest naval fortress in England
had been left unguarded, a fact so extraordinary as to be exceedingly
suspicious. His water-ray apparatus, a recent development of the X-rays
which enabled him to see under water for a distance of fifty yards, had
detected no contact mines, and yet Spithead ought to be enstrewn with
them, just as it ought to have been swarming with submarines and
destroyers. There must be some deep meaning to such apparently
incomprehensible neglect, but what was it?

If his brother Denis had not happened to recognise Captain Count Karl
von Eckstein and haled him so unceremoniously on board the _Ithuriel_,
and if his portmanteau full of papers had been got on board a French
warship, instead of being left for the inspection of the British
Admiralty, that reason would have been made very plain to him.

Completely mystified, and fearing that either he was going into some
trap or that some unforeseen disaster had happened, he swung round, ran
out past the forts and rose into the air again. When he had reached the
height of about a thousand feet, three rockets rose into the air and
burst into three showers of stars, one red, one white, and the other
blue. It was the Tricolour in the air, and the signal from the French
Admiral to commence the attack. Castellan's orders were to cripple or
sink the battleships of the Reserve Fleet which was moored in two
divisions in Spithead and the Solent.

The Spithead Division lay in column of line abreast between Gilkicker
Point and Ryde Pier. It consisted of the _Formidable_, _Irresistible_,
_Implacable_, _Majestic_ and _Magnificent_, and the cruisers _Hogue_,
_Sutlej_, _Ariadne_, _Argonaut_, _Diadem_ and _Hawke_. The western
Division consisted of the battleships _Prince George_, _Victoria_,
_Jupiter_, _Mars_ and _Hannibal_, and the cruisers _Amphitrite_,
_Spartiate_, _Andromeda_, _Europa_, _Niobe_, _Blenheim_ and _Blake_.

It had of course been perfectly easy for Castellan to mark the position
of th