Del Mar went on up to the top floor and out through the open scuttle to the roof. "That's how he got away, all right," he muttered to himself, then looking up he exclaimed under his breath, as his eye caught something far off, "The deuce—what's that?"
Leaning down to the scuttle, he called, "Jenkins—my field-glasses—quick!"
One of his men handed them to him and he adjusted them, gazing off intently. There he could see what looked like a squad of cavalry galloping along headed by an officer and a rough looking individual.
"Come—we must get ready for an attack!" he shouted diving down the scuttle again.
In the laboratory dining-room, his men, recalled, hastily took his orders. Each of them seized one of the huge black rubber newly completed gas bombs and ran out, making for a grove near-by.
Quickly as Del Mar had acted, it was not done so fast but that the troop of cavalry as they pulled up on the top of a hill and followed the directing finger of the tramp could see men running to the cover of the grove.
"Forward!" shouted Woodward.
As if all were one machine, the men and horses shot ahead, until they came to the grove about the old hotel. There they dismounted and spread out in a semi-circular order, advancing on the grove. As they did so, shots rang out from behind the trees. Del Mar's men, from the shelter were firing at them. But it seemed hopeless for the fugitives.
"Ready!" ordered Del Mar as the cavalrymen advanced, relentless.
Each of his men picked up one of the big black gas bombs and held it high up over his head.