I may say in passing that I purposely am refraining from formulating any theory whatever until I have ascertained everything which it is possible to learn in the matter.  In this way I hope to avoid the error into which the detective is so prone to fall.  Once you set up an hypothesis you unconsciously, and in spite of yourself, accentuate unduly the importance of all data making toward that hypothesis, while, on the other hand you either utterly neglect, misconstrue, or fail to fully appreciate, the evidence oppugnant to your theory.  In chemical research I gather the material for an entire series of experiments before performing any, so that the first few shall not, either by satisfying or discouraging me, cause me to leave the bush half beaten.

“Let us see how, from the officers’ standpoint, the murder hypothesis now stands.  No assassin, it will be clear to them, could have entered or left this room unobserved.  If, therefore, a man did enter the room and kill our friend, we, all of us, must be his accomplices.”  This remark drew some sort of exclamatory protest from every other person in the room save Browne.

“Ah, that is probably the true solution,” said the artist with ill-concealed disgust.

This remark and the tone in which it was uttered would have been discourteous under any circumstances; at this particular time and in the painful situation in which we all found ourselves it was boorish almost beyond endurance.

There was nothing in Maitland’s manner to indicate that he had heard Browne’s remark, as he quietly continued: 

“You see this cold-blooded view, the mere statement of which causes you all to shudder,—­the more so because one of our number is the daughter of the dead man,—­is not to be entertained a moment and is only mentioned to show the logical chain which will force the officers into the certain conviction that no assassin did enter or leave this room.  What, then, remains of their theory?  Two possibilities.  First, the murderer may have done the deed without entering.  If so, it is clear that he must have made use of the partly-opened window.  This seems so likely that they will seize upon it with avidity.  At first they will suggest that the assassin reached in at the window and struck his victim as he sat by it.  This, they will urge, accounts for our not finding the weapon, and they will be so sure that this is the correct solution of the problem that I shall probably have to point out to them its patent absurdity.  This illustrates the danger of forming an hypothesis from imperfect data.  Remind them that Mr. Darrow did not sit by the window, but eight feet three and one-half inches from it, in almost the exact centre of the room, and their theory falls to the ground, only to be hastily replaced, as a drowning man catches at a straw, by a slightly varied theory.  If the victim sat that distance from the window, they will inform us, it is clear the murderous implement must have been thrown or shot at him by the assassin.”