CHAPTER VI

THE CONNING-TOWER OF THE "OLIVE BRANCH"

PUNCTUALLY at ten o'clock on the following morning Gerald Tregarthen was ushered into the captain's cabin. "Well, sir, what decision have you arrived at?" demanded Captain Brookes.

"No decision at all, sir," replied Tregarthen, firmly. "I want first of all to know what you propose to do with my companion."

"With Mr. Stockton? I suppose I ought, as the pirate you regard me, to hold him as a hostage for your good behaviour. But rest assured, I'll have him shipped aboard the first homeward-bound vessel we sight."

"Before I give you a reply I should like to have a few minutes' conversation with him," said Gerald.

"Your request seems reasonable. You may have fifteen minutes' interview."

While speaking, Captain Brookes had touched the push of an electric bell, and a seaman, evidently a petty officer, was immediately in attendance.

"Take this gentleman to his quarters and desire Mr. Black to bring Mr. Stockton to him."

"Very good, sir," replied the seaman, and holding back the heavy curtains that hung over the door he allowed Tregarthen to precede him.

In less than five minutes Jack Stockton had joined his chum.

"Hulloa, Jack! How have they treated you?"

"Can't complain," was the laconic reply. "They told me you were all right in spite of a crack on the skull. Beyond that I didn't worry much, though I've been thinking about my poor old yacht."

"Yes, it's rough luck," replied Tregarthen. "But she's insured, isn't she?"

"Yes. But what does that matter? I shall never have the same craft again; and, Gerald, she was part and parcel of my existence."

"You'll have another one soon."

"Will I? How do you know?"

"Because they are going to ship you aboard the first vessel we meet."

"Ship _me?_ How about you?"

"Ah! There's the difficulty. You will be sent home, but, worse luck, they are going to keep me here, whether I like it or not."

"Is that a fact? What is this vessel--a pirate?"

"Goodness only knows. But to put the matter in a nutshell, I have to give my decision whether I'll become one of them or not."

"And if you don't?"

"I've been promised something mighty unpleasant."

Thereupon Gerald related the details of the conversation of the previous evening, and the captain's peremptory demand for a definite reply.

"What do you propose to reply?" asked Jack.

"That's what I want to consult you about. You see there's my position to consider. If I do not turn up within thirty-three days from now I shall be branded as a deserter, unless My Lords take gentler measures and mark me down as missing. If I could serve a useful purpose to my country by accepting the man's proposals I'd do it like a shot, subject to certain guarantees."

"Then why not? In any case you are booked. But I say, old fellow, when you are treating for terms, couldn't you stipulate that I am to be retained as well?"

"You?"

"Yes. I admit, Gerald, I don't possess the same qualifications as you do, but at the same time I'm not a duffer afloat. If this vessel is such a wonderful packet, I'd be only too delighted to stay."

"All right," replied Gerald. "My mind's made up. But the quarter of an hour is up, too, so I must be off."

"Well, sir," asked Captain Brookes, "have you come to any conclusion?"

"I am willing, subject to certain conditions, sir," replied Gerald, firmly.

"And those are----"

"That I am to be treated with the respect due to a British naval officer; that I am not called upon to perform any duties prejudicial to my country----"

"That I have already suggested."

"That I may be allowed to dispatch a communication to the Admiralty stating the circumstances under which I am detained here; and, lastly, that my friend Jack Stockton may be allowed to remain here with me, that being his own desire."

"I agree to your requests," replied Captain Brookes, though Tregarthen noted that he used the word "requests" instead of his expression "conditions."

"Very good, sir."

"You quite understand that my orders are to be implicitly obeyed?"

"So long as I am not called upon to commit any act detrimental to my country."

"That has already been decided."

"Too much stress cannot be laid upon that condition, sir."

"Are you prepared to wear the uniform of officers serving on board the _Olive Branch_?"

"No, sir. The only uniform I am entitled to wear is that of the British Navy. As that is, of course, impossible in these circumstances, I must wear mufti."

"Very well, then," replied the captain. "Now we will make a tour of the ship and you will be able to form some opinion of her capabilities."

So saying, Captain Brookes led the way to the half-deck, whence by the after ladder he gained the quarter-deck. Unlike ships of the British Dreadnought type, the quarter-deck was situated in the after end of the ship, but Gerald noticed that the officers who were walking up and down kept religiously to the port side, leaving the starboard side to the use of the captain. This caused him to wonder how the similarity between the customs of the Royal Navy and those of the mysterious ship was to be accounted for.

Touching his cap to the quarter-deck Gerald found himself upon a vessel apparently of not less than 10,000 tons displacement, or a little more than half of a modern Dreadnought. She was, as far as he could judge, about 300ft. in length, and 60ft. in breadth. She was flush decked; a low slender funnel, a motor cutter and launch, a massive conning-tower, a pair of turrets, and the necessary hatchways and companions alone occupying the centre line. Placed _en echelon_ were two more turrets, but in none of these were guns mounted, although each turret had two embrasures.

At frequent intervals along the deck were plates of thin steel inclined at an angle of 45degs.

"These are wind screens," observed Captain Brookes. "They are an absolute necessity, I can assure you."

"Don't hesitate to put any questions you may feel inclined to ask," he continued. "It will be to your interests as well as mine for you to do so. I noticed you were looking at the turrets. These are as yet without their armament, although I hope within a day or two to have the guns in position."

"Then at present you are without means of offence?"

"You will hardly care to make that assertion when you have completed your first inspection of the _Olive Branch_. But what speed do you think we are doing?"

Tregarthen looked over the side. There was a long, gentle swell setting in from the west, but so great was the ship's rate of speed that she appeared to be travelling over a succession of short, steep seas, yet without the faintest suspicion of a roll or a lurch.

"Forty-five," he hazarded.

"Add twenty to it and you will be nearer the mark. Mr. Gimlette," he added, addressing the officer of the watch, "will you please let me have the present reading of the log?"

The officer ran aft to where the patent log indicator on the taffrail was merrily ringing at less than every fifteen seconds.

"Sixty-seven point five knots, sir."

The reply was given smartly, but in a manner that suggested this speed was an ordinary occurrence. Tregarthen could only gasp in astonishment. It meant the _Olive Branch_ was doing an equivalent to a fraction under seventy-five land miles an hour. Were it not for the wind screens it would be almost a matter of impossibility to face the hurricane that whistled overhead.

"You may have noticed the almost total absence of a bow wave," continued the captain. "This is owing to the vessel's remarkable flare--for which the designers must take the credit. By means of an ingenious contrivance the displaced water is led close alongside, yet the 'skin friction' of the hull is not increased. The effect of this diversion is to give the propellers a better grip. As a matter of fact, the 'slip' of the propellers amounts to less than 5 per cent. Now we will make our way for'ard to the conning-tower."

"But what is the motive power?" asked Gerald.

"Petrol, paraffin, or, in fact, any inflammable oil capable of passing through the vaporisers. The motors, which can be attended to by a staff of ten engineers only, actuate five propellers. Thus we are not under the obligation of having to carry stokers. As a matter of fact, the _personnel_ of the _Olive Branch_, thanks to mechanical appliances of the most modern type, amounts to 105 officers and men."

The conning-tower consisted of a circular armoured structure 25ft. in diameter, and barely 5ft. above the upper deck. Around the walls were electrical indicators and a maze of pipes painted in distinctive colours similar to those on board a British man-of-war. But the apparatus that riveted Gerald's attention was a board composed of copper and zinc squares resembling a draught board, with a pair of pointers at two adjacent corners. This device travelled on steel lines that formed an almost complete circle, a gap being left in the direction of the after end of the ship.

"Now, Mr. Tregarthen, what do you suppose this arrangement is for?"

"It appears to me to be a sort of position-finding instrument."

"It is more than that. But first I must request you to maintain a strict secrecy regarding what you see in the conning-tower, at least until I withdraw this restriction. Beyond that you are at perfect liberty to discuss with your companion any details concerning the ship," replied Captain Brookes. "Before you left Poole Harbour did you see a report in the papers concerning the German cruiser _Zietan_?"

Like a flash the truth swept across Tregarthen's mind. The ex-Brazilian vessel, _Almirante Constant_, the mysterious agency that had temporarily incapacitated the _Zietan_, and the ship on which he stood were one and the same. So astonishing was the revelation that even he--an iron-nerved naval officer--gasped with amazement. The captain, who was watching the effect of his question, kept silent, awaiting Gerald's reply.

"I did," he assented after a prolonged interval. "But how did you do it? And how were you aware?"

"One question at a time, please. I am on the point of showing you a somewhat ingenious device; what it has already done I will inform you of in due course. This chequered board is divided, as you see, into eighty-one squares, each division representing one square mile. Thus a 'field,' meaning nine miles in either direction, is at my command. Now, supposing a hostile ship is sighted. Her position is determined by the ordinary range-finding instruments. By placing these two pointers on the square representing the ship's position--the pointers, as you will observe, being capable of alteration of length--I release a wireless current, which I prefer to term the Z-ray--upon the enemy's ship. Instantly the whole of her electrical gear is completely disorganised, and, knowing as you do the vital importance of electricity on board a modern man-of-war, you can realise what it means."

"Then you have already committed a hostile action against the ship of a friendly nation?"

"I suppose I have. It is necessary to experiment, and having good cause to try my device upon a German ship, I proceeded to do so. I am fully aware of the results it occasioned while I kept the _Zietan_ under the influence of the Z-rays."

"However did you manage to know that?" asked Tregarthen. "Have you put into any port since leaving the Tyne?"

"I have neither put into port nor have I entered into communication with any vessel excepting your yacht, so obtaining information by those means is entirely out of the question. How I did find out the results of my experiment I will inform you shortly. But to return to this device. You will doubtless have observed that there are two pairs of pointers? Those with a black disc are merely deterrents. Any vessel that persists in forcing an action after receiving the stern warning given by these pointers has only herself to blame for the consequences; for the moment the pointers with the red disc are superimposed upon the others the fate of the _Olive Branch's_ antagonist is sealed."

"How?" asked Gerald, with ever-growing interest.

"The conjunction of the red-disced pointers release a super charge of electricity--which I term the ZZ-rays--and her magazines are instantly exploded."

"In that case why do you require guns on board? I understood you to say that you expected to have her armament in position in the course of a few days."

"Chiefly as a matter of precaution. The slightest defect in a terminal, switch, or wire might throw the whole of the electrical apparatus out of gear. But there is another danger I have to guard against--the danger of annihilation from the sky. This device you see here has taken me fifteen years of unremitting toil and thought to perfect, and perfected it is as far as my original plans were concerned. But within recent years the advent of the airship and aeroplane has tended to revolutionise warfare. In order to negative the possible ill results of the ZZ-rays to the vessel that releases them the indicator board is arranged so that the minimum range is nine miles. Thus I can put a vessel out of action at any distance between nine and eighteen miles. The Z-rays, having a comparatively low electro-motive force, can be brought into play at a distance of two miles, without danger to the _Olive Branch's_ delicate mechanism. It consequently follows that to use the rays within the distance of 1,000ft.--the effective range of an airship--the consequences would be disastrous to us. I therefore have to rely on other means. Now I think I have explained the contents of the conning-tower pretty fully, so we will resume our tour."

"But what are these for?" asked Tregarthen, pointing to a triple row of metal studs fixed to a mahogany board on the side of the conning-tower.

"To control the gun fire. When the ordnance is installed I'll explain their use. But we will now ascend to the flying bridge."

With the wind howling over this exposed position like a veritable tornado Gerald was glad to gain the shelter of a diminutive chart-house. Here was the electrical steering apparatus, but, to his unbounded astonishment, Tregarthen found that the place was untenanted, the only other occupants of the bridge being a lieutenant and a seaman, both of whom, glass in hand, were scanning the horizon.

"Don't you keep a hand at the helm?" he asked.

Captain Brookes shook his head. "Not on long ocean voyages," he replied. "The ship steers herself. Like plenty of other problems, it's simple when you know how. The _Olive Branch's_ steering apparatus is on the same principle as that of a Whitehead torpedo. The course is set by means of a pointer on the compass-card. The slightest deviation causes a small valve to be opened which actuates the rudder. Of course in confined waters or on going into action we use the steering-gear in the conning-tower."

"I can scarcely grasp the meaning of these wonders," remarked Tregarthen.