Q. Mr. Frazier, we were just beginning to discuss, before the recess, Commission Exhibit 559, which is a picture, as you described it, of Exhibit No. 543 and a test cartridge under a microscope * * * ?

Mr. Frazier. Yes, sir.

Q. Could you discuss, by using that picture, some of the markings which you have seen under the microscope and on the basis of which you made your identification ?

A. Yes, sir. In the photograph I have drawn some small circles and numbered them, those circles, correspondingly on each side of the photograph. The purpose of the circles is not to point out all the similarities, but to call attention to some of them and to help orient in locating a mark on one with a mark on the opposite side of the photograph. In general the area shown is immediately outside of the firing pin in the bolt of the 139 rifle, on the left side of the photograph, and Commission Exhibit 543 on the right side.

The circles have been drawn around the dents or irregularly shaped ridges, small bumps, and depressions on the surfs of the metal in six places on each side of the photograph. It. is an examination of these marks, and all of the marks on the face of the breech, microscopically which permits a conclusion to be reached. The photograph itself actually is a substitute to show only the type of marks found rather than their nature, that is, their height, their width, or their relationship to each other, which is actually a mental, visual, comparison on the two specimens themselves.

Q. Referring for a second to this mental, visual, comparison, Mr. Frazier, would a person without firearms training--fire-arms-identification training--be able to look under a microscope