Absolute followed the of young Burton and, as all were intently listening, there sounded through the soft stillness of the night a strange, piercing cry,—the baying of a bloodhound following the trail of a person. It was neither a bark nor a , but a mixture of the two,—a deep howl that might well fill a fleeing with shivering fear.  
“That’s Zip,” said his pleased owner; “he will be here in a few minutes.”
 
“He has a voice,” said Master Hall; “I never heard the like.”
 
Mike Murphy, who had been one of the most absorbed of listeners and was seated near the guest, rose to his feet and emitted a cry which, so far as the listeners could tell, was an absolutely perfect imitation of that of the dog.
 
“That’s wonderful!” exclaimed Burton; 213“it would deceive any one except the dog himself.”
 
“And why not him?” asked Alvin Landon.
 
“Because he does not answer—there he comes!”
 
In the dim moonlight, as every eye was turned in the direction of the beach leading toward Uncle Elk’s cabin, the saw a black, medium sized dog approaching at full speed, his sturdy figure rapidly assuming definite form. It was to be that Burton had come through the wood itself, whereas the animal was traversing the beach, where the way was more open, yet he was keeping to the trail as unerringly as an arrow driven from the bow.
 
“Hide yourself,” whispered Mr. Hall.
 
“There is no place where I can hide from him.”
 
The next instant the hound with undiminished speed bounded up the steps at the end of the porch, dashed between the boys, and impinged with such force against his master that he was knocked backward for a pace or two. Bending over, Burton patted the big head, and Zip in his excess of delight bounded round the youth and wagged his tail so hard that it swayed his haunches correspondingly, and it really seemed an instance of the tail wagging the dog.
 
“Don’t you think Zip will appreciate something in the form of a meal?” asked Mr. Hall.
 
“He certainly will; a dog is always hungry, and more than half a day has passed since he ate; nothing suits him better than raw meat.”
 
“We have a supply, and he shall feast to his heart’s content.”
 
So he did, the food being brought out and placed in front of the guest, who would have eaten a good deal more had his master permitted. accepting the decision, Zip lay down at young Burton’s feet, and happy throughout the remainder of the evening, and glad to stay outside until the youth rejoined him in the morning.
 
“You know what matchless policemen the Belgian dogs make in that country, in France, and in New York and other cities. Some three years ago Long Island became 215so by thieves that Robert E. Kerkham, of the railway police, saw that something drastic had to be done. The thieves station safes, burglarized private and more than once killed and injured railway policemen while they were trying to arrest the criminals. Those men used fleet horses and , and despite everything that could be done, grew bolder and more successful.
 
“Superintendent Kerkham, finding that his patrolmen were powerless, to call in the help of dogs, with whose striking success abroad and at home he was familiar, but he made a new departure by taking bloodhounds instead of the usual police dogs, for the former would not only guard property but would track the thieves. He bought a pair from the stock imported from England more than twenty years ago. These are of the purest blood, and superior to all others. Zip is from the same stock. A of this dog is that in no circumstances will he take up a doubtful trail, but will pick up the true , no matter how faint, and never abandon it so long as it actually exists. They know not the 216meaning of fear, and will stick to their work so long as they can move or breathe. Some of those dogs have pedigrees that reach backward to the time of William the .
 
“The couple which Mr. Kerkham purchased are named Bob and Nellie. They had to be trained, but they learned fast. They will take the scent from any article that has been lately handled by the person they are after.”
 
“How old a trail will serve them?” asked the Scout Master.
 
“Of course the freshest scent is the best. Zip was all of seven hours behind me to-day. I have tested him on double that time and he seemed to have little or no difficulty. They have taken a trail twenty-four hours old, and what it is that guides them in such a case is more than any one can understand. A man is known to have left a house at a certain time, and twenty hours later it is decided to pursue him with the aid of a bloodhound. A glove, or hat, or shoe that he is known to have worn is held in front of the dog; he at it, dashes out of doors, circles back and and around the grounds until he strikes the corresponding scent; up goes his head, his tail wags and he bays his pleasure. A hundred yards farther, and he drops his nose to the ground to make sure he has not lost his clue.
 
“Perhaps the scent grows faint or disappears. In that case he runs back and circles about until he picks it up again, when he is off once more. You must remember that while all this is going on there is a man at the , for this is necessary to protect the thief. As the trail grows fresher, the fierce eagerness of the hound increases; he knows he is close upon his and sharp words and powerful pulling are necessary to prevent him from bounding straight at the throat of the . Should he start to run it is almost impossible to restrain the dog, but when he sees the criminal is under arrest, he is satisfied, becomes quiet, and is ready to tackle the next job.”
 
“Will you tell us of some of the exploits of Bob and Nellie, who you say are perfect of their kind?”
 
“I cannot recall a quarter of them. One 218thing that Bob did was astonishing because it was at the beginning of his training and the scent was fourteen hours old. He caught it from a bag which the thieves had used to wrap about their hands in breaking a window. As true as the needle to the pole, Bob led his master through and side streets, across vacant lots, along the purlieus of a straggling village to a house near the highway. This was circled once, and then he dashed to a barn at the rear, through the open door, and sprang at a young man who was engaged in skinning a he had trapped.
 
“The fellow was indignant and denied all knowledge of the cr............