Translations for effective in French

Here are paragraphs from public domain books translated:

“I have already told you that your reports reached me rapidly, being forwarded instantly from Baker Street to Coombe Tracey. They were of great service to me, and especially that one incidentally truthful piece of biography of Stapleton’s. I was able to establish the identity of the man and the woman, and knew at last exactly how I stood. The case had been considerably complicated through the incident of the escaped convict and the relations between him and the Barrymores. This also you cleared up in a very effective way, though I had already come to the same conclusions from my own observations.

« Je vous ai déjà dit que vos rapports, expédiés sur-le-champ de Baker street à Coombe Tracey, me parvenaient rapidement. Ils m’étaient fort utiles, et principalement celui qui contenait la biographie de Stapleton. Il me permit d’établir l’identité de l’homme et de la femme ; il affermit le terrain sous mes pieds. « L’évasion du convict et ses relations avec les Barrymore embrouillèrent considérablement les choses, mais vous dégageâtes la lumière d’une façon très efficace, bien que mes observations personnelles m’eussent déjà imposé les mêmes conclusions.

The Hound of the Baskervilles, by Arthur Conan Doyle

Le Chien des Baskerville, de Arthur Conan Doyle