Harrington Strong is a pseudonym Johnston McCulley (1883 - 1958) was using.
The Brand of Silence is a Detective Story first published in 1919 by Street & Smith (New York)
This short novel has a very pulpy undertone. A little excerpt will tell more than my words:
Farland started moving slowly toward them, making his way through the crowd in such fashion that he did not attract too much attention to himself. He was feeling a sudden interest in this case. There were great possibilities in the fact that two persons connected with it from different angles were in conversation.
As he made his way toward the show window, he remembered how this George Lerton had tried to induce Sidney Prale to leave the city and remain away, and how, afterward, he had denied that he had seen Prale on Fifth Avenue and had spoken to him.
"He's connected with this thing in some way," Farland told himself. "It's my job to discover exactly how."
But he was doomed to be disappointed. Before he could get near enough to make an attempt to overhear what they were saying, they suddenly parted. Kate Gilbert went into the shop, and George Lerton crossed the street and hurried down the Avenue.
It was no use wasting time on Kate Gilbert. Farland knew where to find her if he wanted her, and he knew there would be no use in shadowing her now, since she probably had gone into the shop to purchase a hat. But George Lerton was quite another matter.
The detective did not hesitate. He swung off down Fifth Avenue in the wake of George Lerton.
Farland was a rough and ready man, and he had little liking for male humans of the George Lerton type. Lerton always dressed in the acme of fashion, running considerably to fads in clothes, appearing almost effeminate at times. And yet it was said in financial circles that Lerton was far from being effeminate when it came to a business deal. There had been whispers about his dark methods, and it was well known that a business foe got small sympathy or consideration from him. He was a fashionable cut-throat without any of the milk of human kindness in his system.