And just as a man to some extent snares his personality with his near blood-relations in the form of family resemblances, so his handwriting often shows a subtle likeness to that of his near relatives.
You must have noticed, as I have, how commonly the handwriting of one brother resembles that of another, and in just this peculiar and subtle way.

The inference, then, from Mr.Britton's statement is, that if the signature of the will was forged, it was probably forged by a relative of the deceased.

But the only relative in question is his brother John.
"All the facts, therefore, pointed to John Blackmore as the person who occupied these chambers, and I accordingly adopted that view as a working hypothesis." "But this was all pure speculation," objected Mr.Winwood.
"Not speculation," said Thorndyke.

"Hypothesis.

It was ordinary inductive reasoning such as we employ in scientific research.