The inspector seemed for the first time disturbed, and said, “Of course I should be glad to clear you altogether now.”

The smith walked out of his yard with the same long and easy stride, and returned to his two friends from Greenford, who were indeed friends of nearly everyone present.  Each of them said a few words which no one ever thought of disbelieving.  When they had spoken, the innocence of Simeon stood up as solid as the great church above them.

One of those silences struck the group which are more strange and insufferable than any speech.  Madly, in order to make conversation, the curate said to the Catholic priest: 

“You seem very much interested in that hammer, Father Brown.”

“Yes, I am,” said Father Brown; “why is it such a small hammer?”

The doctor swung round on him.

“By George, that’s true,” he cried; “who would use a little hammer with ten larger hammers lying about?”

Then he lowered his voice in the curate’s ear and said:  “Only the kind of person that can’t lift a large hammer.  It is not a question of force or courage between the sexes.  It’s a question of lifting power in the shoulders.  A bold woman could commit ten murders with a light hammer and never turn a hair.  She could not kill a beetle with a heavy one.”

Wilfred Bohun was staring at him with a sort of hypnotised horror, while Father Brown listened with his head a little on one side, really interested and attentive.  The doctor went on with more hissing emphasis: 

“Why do these idiots always assume that the only person who hates the wife’s lover is the wife’s husband?  Nine times out of ten the person who most hates the wife’s lover is the wife.  Who knows what insolence or treachery he had shown her—­look there!”

He made a momentary gesture towards the red-haired woman on the bench.  She had lifted her head at last and the tears were drying on her splendid face.  But the eyes were fixed on the corpse with an electric glare that had in it something of idiocy.

The Rev. Wilfred Bohun made a limp gesture as if waving away all desire to know; but Father Brown, dusting off his sleeve some ashes blown from the furnace, spoke in his indifferent way.

“You are like so many doctors,” he said; “your mental science is really suggestive.  It is your physical science that is utterly impossible.  I agree that the woman wants to kill the co-respondent much more than the petitioner does.  And I agree that a woman will always pick up a small hammer instead of a big one.  But the difficulty is one of physical impossibility.  No woman ever born could have smashed a man’s skull out flat like that.”  Then he added reflectively, after a pause:  “These people haven’t grasped the whole of it.  The man was actually wearing an iron helmet, and the blow scattered it like broken glass.  Look at that woman.  Look at her arms.”