What is the theme of "august heat"?

The theme is murder.

The theme of "Auguste heat" is murder.

Explanation:

The author is W. F. Harvey, and it was published in 1910. The short story is about an artist, James Clarence Withencroft. He is describing his strange day, "the most remarkable day" in his life, as he writes, because in a sort of premonition, that is the day in which a "murdered" meets his "murderer", or, even better said, in which he mees his murderer, before it actually happens the criminal act, and even before meeting in person.

The story starts in a hot day of August, in which Withencroft is drawing a fat man in a dock, a criminal, after being sentenced. He loved his work and kept it on his pocket. Then he started walking for a while until he found the gate of a monumental mason, name Charles Arkinson, as said in the entrance. He entered by an impulse and found out Arkinson itself working on a piece, but welcomed Withencroft nicely and started chatting. He discovered that the man looked exactly as his morning drawing. And, at the same, the piece Arkinson was sculpting was in the memory of James Clarence Withencroft born in 1860 and deceased in 1900. Withencroft mentioned to Arkinson his name and birthday was exactly the same as the sculpture marked, and also showed him his morning drawing. They were shocked about the coincidences, and none of them could hit on the answers of the mystery behind that. After that, Arkinson convinced Withencroft to stay until midnight but at passing eleven o'clock Withencroft writes that the heat of August could be enough to make a man mad. And this is the end, leaving unanswered questions of a murder.

And this is why, with mystery and terror, W. F. Harvey is developing the theme of murder.