Mr. SPECTER. Well, knowing that, at that time, did you attach any particular significance to the presence of the Negro gentleman, whom you have described, that you saw in window "A"? Mr. ROWLAND. Yes; that is why I brought it to the attention of the FBI agents who interviewed me that day. This was as an afterthought because I did not think of it firsthand. But I did bring it to their attention before they left, and they---- Mr. SPECTER. That was at the interview on the Saturday morning November 23? Mr. ROWLAND. Yes. Mr. SPECTER. Did you think it of sufficient significance to bring it to the attention of any of the other interviewing FBI agents on the balance of the interviews you have described? Mr. ROWLAND. Yes; I did on the following Sunday to the agents who interviewed me where I worked. Mr. SPECTER. How about the following Sunday? Mr. ROWLAND. No; I did not. Mr. SPECTER. Mr. Chief Justice, at this time I move for the admission into evidence of the three exhibits which we have shown this witness. The CHAIRMAN. They may be admitted. Mr. SPECTER. Exhibits Nos. 356, 357, and 358. That completes our questioning, Your Honor. (The documents referred to were marked Commission's Exhibits Nos. 356, 357, and 358 for identification and admitted into evidence.) The CHAIRMAN. Senator Cooper, have you any questions? Senator COOPER. You said earlier that you had been much interested in and pursued studies in sounds, I believe? Mr. ROWLAND. I have studied quite a bit of electronics, sound. Math and science is what I like. Senator COOPER. You said you had read books on this subject. Did you ever conduct any experiments yourself? Mr. ROWLAND. Yes; in the form of--there is a theory that sound is a basis of a transmitter and a receiver, that you have to have a receiver to have sound. There is a theory that if a tree falls down in the middle of a forest and there is nobody around where they can hear it, there is no sound. Well, I have conducted experiments on this, and I--it is very interesting, very fascinating, but you can't prove it or you can't disprove it because if you have got a microphone there you have got a receiver. Senator COOPER. Did you ever conduct any experiments with rifles, firing a rifle in relation to sound? Mr. ROWLAND. Yes; in a firing range. Senator COOPER. Beg pardon? Mr. ROWLAND. Firing range. Senator COOPER. Yes. Mr. ROWLAND. I did conduct a few experiments. One of them was firing a bullet over water; you know, we were using a set of wood blocks to fire into, so we had a big vat of water that we were firing over, and we had several different articles and composition floating on the water, trying to measure the effect of the sound wave upon that. Such as this we did conduct. Senator COOPER. I think you did say that when you heard the first report that you considered it to be a rifle shot?