“Exactly so.  But I do not wish you to think that I have observed anything particular.”

“Certainly not.  Still, you think there would be no harm in my writing to Marian to say that her behavior has attracted your notice, and——­”

“Good heavens, Mr. Conolly, you must not mention me in the matter!  You are so innocent—­at least so frank, so workmanlike, if I may say so, in your way of dealing with things!  I would not have Marian know what I have said—­I really did not notice anything—­for worlds.  You had better not write at all, but just go down as if you went merely to enjoy yourself; and dont on any account let Marian suspect that you have heard anything.  Goodness knows what mischief you might make, in your—­your ingenuousness!”

“But I should have thought that the opinion of an old and valued friend like yourself would have special weight with her.”

“You know nothing about it.  Clever engineer as you are, you do not understand the little wheels by which our great machine of society is worked.”

“True, Mrs. Leith Fairfax,” he rejoined, echoing the cadence of her sentence.  “Educated as a mere mechanic, I am still a stranger to the elegancies of life.  I usually depend on Marian for direction; but since you think that it would be injudicious to appeal to her in the present instance——­”

“Out of the question, Mr. Conolly.”

“—­I must trust to your guidance in the matter.  What do you suggest?”

Mrs. Fairfax was about to reply, when the expression which she habitually wore like a mask in society, wavered and broke.  Her lip trembled:  her eyes filled with tears:  she rose with a sniff that was half a sob.  When she spoke, her voice was sincere for the first time, and at the sound of it Conolly’s steely, hard manner melted, and his inhuman self-possession vanished.

“You think,” she said, “that I came here to make mischief.  I did not.  Marian is nothing to me:  she does not even like me; but I dont want to see her ruin herself merely because she is too inexperienced to know when she is well off.  I have had to fight my way in London:  and I know what it is, and what the world is.  She is not fit to take charge of herself.  Good-bye, Mr. Conolly:  you are a great deal too young yourself to know the danger, for all your cleverness.  You may tell her that I came here and gossipped against her, if you like.  She will never speak to me again; but if it saves her, I dont care.  Good-bye.”

“My dear Mrs. Fairfax,” he said, with entire frankness, “I am now deeply and sincerely obliged to you.”  And in proof that he was touched, he kissed her hand with the ease and grace of a man who had been carefully taught how to do it.  Mrs. Fairfax recovered herself and almost blushed as he went with her to the door, chatting easily about the weather and the Addison Road trains.

She was not the last visitor that evening.  She had hardly been fifteen minutes gone when the Rev. George presented himself, and was conducted to the laboratory, where he found Conolly, with his coat off, surrounded by apparatus.  The glowing fire, comfortable chairs, and preparations for an evening meal, gladdened him more than the presence of his brother-in-law, with whom he never felt quite at ease.