"Well, good-bye," said Mort, as he left, while Bert went to the barn, to see that the chemical tank was properly filled, in readiness for an alarm. As yet, beyond the one blaze in a small shed in the village, the engines had not been tested at a real fire, nor had the new alarm system been called on to show how much of an aid it was in enabling the department to respond quickly. Several boxes had been installed in different parts of the town, all running to the two fire-houses, as the basement of the town hall and Cole's barn were designated. By means of a simple switchboard arrangement, and a code of signals, given on a gong, it could be told at once which box was pulled. In addition the new bell on the tall steel tower would ring an alarm to awaken those members of the department who were asleep at home. There was a short meeting of the fire department one night, in Cole's barn, where various matters were talked over, and the boys had not dispersed more than an hour, when there sounded an alarm from the tower. At the same time there rang out on the apparatus in Cole's barn, the number of a box located near the Stockton mansion. "There's another fire at the house of mystery," cried Cole, for the boys had given the mansion that designation. "Come on, fellows. Let's see if we can't do better this time than we did with our hand engine." While he was speaking he was drawing on his rubber boots, for, like his companions, he had gotten ready for bed. Before the alarm had ceased ringing (for it sounded the box number automatically four times, once it was started) the engine was being pulled out of quarters. There were only eight boys on duty in the barn, and the task of pulling the heavy engine up the hill to the Stockton mansion was not easy. But, before they were half way there, they were met by several of their comrades, who grabbed the rope. "Come on! Come on!" yelled Bert, who was among the first to arrive from home. "Don't let the fire get too much of a start!" They toiled on, and, as they rounded a and came in sight of the big house, there was not a sign of fire. "That's queer," remarked the young chief. "I wonder if there's something wrong with the signal apparatus." "What's the matter, boys? Out for a practice drill?" asked a voice, and Herbert and his chums saw, in the glare from the lamps on the engine, Mr. Alfred Muchmore coming out of the driveway that led to the big house. "We came in response to a fire alarm," said Bert, "but I don't see any blaze." "Blaze? There isn't any. I don't understand it. I don't want you boys around here. You'd better leave." That was rather queer, coming from a man to whom they expected to be of service. Bert and his chums were puzzled.