Translations for tangible in French

Here are paragraphs from public domain books translated:

"No, I do not think so. I think that there was probably some more tangible cause. And now, Miss Stoner, we must leave you, for if Dr. Roylott returned and saw us, our journey would be in vain. Good-bye, and be brave, for if you will do what I have told you, you may rest assured that we shall soon drive away the dangers that threaten you.	— Je ne le pense pas et je crois à une cause plus tangible. Maintenant, miss Stoner, il faut que nous vous quittions, car si le docteur Roylott revenait et nous trouvait ici, notre coup serait manqué. Au revoir, et soyez courageuse, car si vous faites ce que je vous ai dit, vous ne courrez bientôt plus aucun danger.
The Adventures of Sherlock Holmes, by Arthur Conan Doyle	Les Aventures de Sherlock Holmes, de Arthur Conan Doyle