Part 25 (1/2)

”In three minutes we shall be ready for action,” he said, glancing at his watch; and then, turning a small wheel which raised the muzzle of the gun so as to point it at a higher angle in the direction of the sky, he waited until the s.p.a.ce of time he had mentioned had elapsed.

The officers stood aside conversing in an undertone. This man Mackenzie had invented this strange-looking weapon, and only one had been made. It had some months before been submitted to the War Office, but they had declined to take it up, believing that a patent they already possessed was superior to it; yet Mackenzie had nevertheless thrown his whole soul into his work, and meant now to show his superiors its penetrative powers, and put its capabilities to practical test. Again he glanced at his watch, and quickly pulled back another lever, which caused the motor to revolve at twice the speed, and the gun to emit a low hissing sound, like escaping steam. Then he stepped back to the officers, saying--

”I am now prepared. It will go up as straight and quickly as a rocket, but we must catch it before it ascends two miles, for the clouds hang low, and we may lose it more quickly than we imagine.”

The gunners stood in readiness, and the two officers looked away over Craigmillar towards the grey distant sea. Dawn was spreading now, and the haze was gradually clearing. They all knew the attempt would be made ere long, before it grew much lighter, so they stood at their posts in readiness, Mackenzie with his hand upon the lever which would regulate the discharge.

They were moments of breathless expectancy. Minute after minute went by, but not a word was spoken, for every eye was turned upon the crest of a certain ridge nearly three miles away, at a point where the country was well wooded.

A quarter of an hour had thus elapsed, when Mackenzie suddenly shouted, ”Look, lads! _There she goes!_ Now, let's teach 'em what Scots can do.”

As he spoke there rose from behind the ridge a great dark ma.s.s, looking almost spectral in the thin morning mist. For a moment it seemed to poise and swing as if uncertain in its flight, then quickly it shot straight up towards the sky.

”Ready?” shouted Mackenzie, his momentary excitement having given place to great coolness. The men at their posts all answered in the affirmative. Mackenzie bent and waited for a few seconds sighting the gun, while the motor hummed with terrific speed. Then shouting ”Fire!”

he drew back the lever.

The gun discharged, but there was no report, only a sharp hiss as the compressed air released commenced to send charge after charge of dynamite automatically away into s.p.a.ce in rapid succession!

None dared to breathe. The excitement was intense. They watched the effect upon the Russian balloon, but to their dismay saw it still rapidly ascending and unharmed!

It had altered its course, and instead of drifting away seaward was now travelling towards Duddingston, and making straight for Edinburgh, pa.s.sing above the Russian camp.

”Missed! _missed!_” Mackenzie shrieked, turning back the lever and arresting the discharge. ”It's four miles off now, and we can carry seven and three-quarters to hit a fixed object. Remember, lads, the fate of Auld Reekie is now in your hands! Ready?”

Again he bent and sighted the gun, raising the muzzle higher than the balloon so as to catch it on the ascent. The motor hummed louder and louder, the escaping air hissed and turned into liquid by the enormous pressure, then with a glance at the gauge he yelled ”Fire!” and pulled back the lever.

Dynamite sh.e.l.ls, ejected at the rate of 50 a minute, rushed from the muzzle, and sped away.

But the Demon of War, with its whirling propellers, continued on its swift, silent mission of destruction.

”Missed again!” cried one of the men, in despair. ”See! it's gone!

We've--good heavens!--_why, we've lost it--lost it!_”

Mackenzie, who had been glancing that moment at the gauges, gazed eagerly up, and staggered back as if he had received a blow. ”It's disappeared!” he gasped. ”_They've outwitted us, the brutes, and nothing now can save Edinburgh from destruction!_”

Officers and men stood aghast, with blanched faces, scarce knowing how to act. The destructive forces in that controllable balloon were more than sufficient to lay the whole of Edinburgh in ruins; and then, no doubt, the enemy would attempt by the same means to destroy the British batteries on the neighbouring hills. Already, along the valleys fighting had begun, for rapid firing could be heard in the direction of Gilmerton, and now and then the British guns on the Braid Hills behind spoke out sharply to the Russians who had occupied Loanhead, and the distant booming of cannon could be heard incessantly from Corstorphine.

Suddenly a loud, exultant cry from Mackenzie caused his companions to strain their eyes away to Duddingston, and there they saw high in the air the monster aerial machine gradually looming through the mist, a vague and shadowy outline. It had pa.s.sed through a bank of cloud, and was gradually reappearing.

”Quick! There's not a moment to lose!” shrieked Mackenzie, springing to the lever with redoubled enthusiasm, an example followed by the others.

The motor revolved so rapidly that it roared, the gauges ran high, the escaping air hissed so loudly that Mackenzie was compelled to shout at the top of his voice ”Ready?” as for a third time he took careful aim at the misty object now six miles distant.

The War Demon was still over the Russian camp, and in a few moments, travelling at that high rate of speed, it would pa.s.s over Arthur's Seat, and be enabled to drop its deadly compounds in Princes Street. But Mackenzie set his teeth, and muttered something under his breath.

”_Now!_” he e.j.a.c.u.l.a.t.ed, as he suddenly pulled the lever, and for the last time sent forth the automatic shower of destructive sh.e.l.ls.

A second later there was a bright flash from above as if the sun itself had burst, and then came a most terrific explosion, which caused the earth to tremble where they stood. The clouds were rent asunder by the frightful detonation, and down upon the Russian camp the debris of their ingenious invention fell in a terrible death-dealing shower. The annihilation of the dastardly plot to wreck the city was complete. Small dynamite sh.e.l.ls from Mackenzie's pneumatic gun had struck the car of the balloon, and by the firing of half a ton of explosives the enemy was in an instant hoist with his own petard.