| I. | The Silent Bullet |
| II. | The Scientific Cracksman |
| III. | The Bacteriological Detective |
| IV. | The Deadly Tube |
| V. | The Seismograph Adventure |
| VI. | The Diamond Maker |
| VII. | The Azure Ring |
| VIII. | “Spontaneous Combustion” |
| IX. | The Terror In The Air |
| X. | The Black Hand |
| XI. | The Artificial Paradise |
| XII. | The Steel Door |
CRAIG KENNEDY'S THEORIES
“It has always seemed strange to me that no one has ever endowed a professorship in criminal science in any of our large universities.”
Craig Kennedy laid down his evening paper and filled his pipe with my tobacco. In college we had roomed together, had shared everything, even poverty, and now that Craig was a professor of chemistry and I was on the staff of the Star, we had continued the arrangement. Prosperity found us in a rather neat bachelor apartment on the Heights, not far from the University.
“Why should there be a chair in criminal science?” I remarked argumentatively, settling back in my chair. “I've done my turn at police headquarters reporting, and I can tell you, Craig, it's no place for a college professor. Crime is just crime. And as for dealing with it, the good detective is born and bred to it. College professors for the sociology of the thing, yes; for the detection of it, give me a Byrnes.”
“On the contrary,” replied Kennedy, his clean-cut features betraying an earnestness which I knew indicated that he was leading up to something important, “there is a distinct place for science in the detection of crime. On the Continent they are far in advance of us in that respect. We are mere children beside a dozen crime-specialists in Paris, whom I could name.”
“Yes, but where does the college professor come in?” I asked, rather doubtfully.
“You must remember, Walter,” he pursued, warming up to his subject, “that it's only within the last ten years or so that we have had the really practical college professor who could do it. The silk-stockinged variety is out of date now. To-day it is the college professor who is the third arbitrator in labour disputes, who reforms our currenc