JOURNAL OF CHEMICAL EDUCATION
THE PREPARATION OF PUNCHED CARDS FOR INDEXING INFORMATION GEORGE R. THOMAS Boston University, Boston, Massachusetts
THE punched-card indexing system is deservedly figure. A is a brass master plate the same size as the gaining in popularity. Many, including the author, have considered using it for personal files but have been deterred by the necessary initial investment. It is the purpose of this communication to describe a method whereby ordinary file cards can be converted to pnnched cards a t small cost. Among the dividends
card to be used. Into this the desired system of holes has been drilled. B is a pack of 100 cards. C is a sheet of cardboard used as a spacer. D is a block of wood; in. plywood is satisfactory. A, B, C, and D are squeezed together by hand. One corner is used as a reference corner. This corner should be marked for future reference. The complete stack is lined up by tapping edge U and t,hen edge V on a flat surface. Line segments, P, 0,N, M should form a straight line which is perpendicular to the plane of the surface. The stack is now clamped together as tightly as possible into this position with four %in. C-clamps, one near each comer. A hole is drilled through the complete stack by means of a drill press and the appropriate size drill (s/84 in. is suitable). A round-head bolt through the hole and nut is now used to hold this comer fast. Each corner and the midpoint of each side is then so fixed. Now the drill press is set so that the drill goes through only to the spacer and the remaining holes are drilled. It is of utmost importance to keep / the stack of cards compressed so as to present a solid U' block to the drill and to keep the plane of the stack of preparing one's own cards are the following: first, perpendicular to the drill. The punched cards so made form a convenient pad one can determine easily and economically whether or not the punched-card system will be really useful; from which one can be removed at a time. It has been second, one can set up a system which will uniquely found that a novice can produce 200 cards in about fit his own needs even though the design is not com- one hour. It should be noted that a knitting needle can serve mercially available; third, one is not restricted in any may as to card sizes. Those interested in library as a sorting device. While for the casual user a scissors courses can design many interesting student experi- can be used for coding the cards, it is more convenient to construct a card which will accommodate the comments mound this method. The essenrird fextnrrs of rhe method are shox-n in the mercially available punches.
