Mr. CADIGAN. This exhibit was brought to the laboratory by Special Agent Drain of our Dallas office, who brought all of this evidence in for examination. Mr. EISENBERG. Did you attempt to determine whether Exhibit 142 had the same origin as the paper in Exhibit 677, or might have had the same origin? Mr. CADIGAN. Yes; I examined the two papers--do you wish me to state my opinion? Mr. EISENBERG. Yes; please. Mr. CADIGAN. Well, initially, I was requested to compare the two papers to see if they could have originated from the same source. I first measured the paper and the tape samples. Then I looked at them visually by natural light, then incident light and transmitted light. Mr. EISENBERG. What do you mean by transmitted light? Mr. CADIGAN. Well, light coming right on through the paper. Mr. EISENBERG. Then---- Mr. DULLES. Natural light? Mr. CADIGAN. Yes; natural light. Mr. DULLES. As distinct from electric light? Mr. CADIGAN. Both. In the room I am in you can go over to the window for natural light and use ceiling light for artificial light which has a little different property than the outside light. Mr. DULLES. Yes. Mr. CADIGAN. I looked at the papers under various lighting conditions---- Mr. EISENBERG. Excuse me a minute, Mr. Cadigan, by "transmitted light" you mean the light transmitted when you hold the object between the light source and your own eyes? Mr. CADIGAN. Yes; then I put it under the microscope, and again looked at it from the standpoint of the surface, paper structure, the color, any imperfections. I further noted that on both of the tapes---- Mr. EISENBERG. 142 is the paper bag. Mr. CADIGAN. On 142 and on the tape on 677 there were a series of marks right down about the center of the tape. Mr. EISENBERG. Can you see those visually with the unaided eye, or only under a microscope? Mr. CADIGAN. I can see them visually. The microscope makes it look clearer. Mr. DULLES. What are you pointing to now? Mr. EISENBERG. This line here. Mr. DULLES. Where is this? Mr. CADIGAN. These are a series of lines running right here about a half-inch high, they are very closely spaced. Mr. DULLES. Oh, yes; these are perpendicular lines. Mr. CADIGAN. Yes, sir. Mr. DULLES. Would you like to see these, Mr. Murray? Mr. MURRAY. Yes; thank you. Mr. DULLES. They are quite clear, about a tenth of an inch apart or less than that. Mr. CADIGAN. Well, actually they are 24-1/2 spaces per inch, which would be about 25 lines per inch. Mr. MURRAY. Pockmarks? Mr. CADIGAN. A series of little short marks right close together. Mr. MURRAY. Oh, yes. Mr. DULLES. And they run along about how far on this particular exhibit? Mr. CADIGAN. They run the whole length of the tape. Mr. MURRAY. A comb design. Mr. EISENBERG. Comb in the sense that it is a series of---- Mr. MURRAY. Comb or rake. Mr. EISENBERG. Could you circle that on 677, and mark the portion "A"? Can you still make out the lines on Exhibit 640? Mr. CADIGAN. Oh, yes.