frequently followed are prone to fade, items are not fully permanent, memory is transitory. Yet the
speed of action, the intricacy of trails, the detail of mental pictures, is awe-inspiring beyond all else in
nature.
Man cannot hope fully to duplicate this mental process artificially, but he certainly ought to be able to
learn from it. In minor ways he may even improve, for his records have relative permanency. The first
idea, however, to be drawn from the analogy concerns selection. Selection by association, rather than
by indexing, may yet be mechanized. One cannot hope thus to equal the speed and flexibility with which
the mind follows an associative trail, but it should be possible to beat the mind decisively in regard to the
permanence and clarity of the items resurrected from storage.
Consider a future device for individual use, which is a sort of mechanized private file and library. It
needs a name, and to coin one at random, ``memex'' will do. A memex is a device in which an individual
stores all his books, records, and communications, and which is mechanized so that it may be consulted
with exceeding speed and flexibility. It is an enlarged intimate supplement to his memory.
It consists of a desk, and while it can presumably be operated from a distance, it is primarily the piece
of furniture at which he works. On the top are slanting translucent screens, on which material can be
projected for convenient reading. There is a keyboard, and sets of buttons and levers. Otherwise it
looks like an ordinary desk.
In one end is the stored material. The matter of bulk is well taken care of by improved microfilm. Only a
small part of the interior of the memex is devoted to storage, the rest to mechanism. Yet if the user
inserted 5000 pages of material a day it would take him hundreds of years to fill the repository, so he
can be profligate and enter material freely.
Most of the memex contents are purchased on microfilm ready for insertion. Books of all sorts,
pictures, current periodicals, newspapers, are thus obtained and dropped into place. Business
correspondence takes the same path. And there is provision for direct entry. On the top of the memex
is a transparent platen. On this are placed longhand notes, photographs, memoranda, all sort of things.
When one is in place, the depression of a lever causes it to be photographed onto the next blank space
in a section of the memex film, dry photography being employed.
There is, of course, provision for consultation of the record by the usual scheme of indexing. If the user
wishes to consult a certain book, he taps its code on the keyboard, and the title page of the book
promptly appears before him, projected onto one of his viewing positions. Frequently-used codes are
mnemonic, so that he seldom consults his code book; but when he does, a single tap of a key projects it
for his use. Moreover, he has supplemental levers. On deflecting one of these levers to the right he runs
through the book before him, each page in turn being projected at a speed which just allows a
recognizing glance at each. If he deflects it further to the right, he steps through the book 10 pages at a
time; still further at 100 pages at a time. Deflection to the left gives him the same control backwards.
A special button transfers him immediately to the first page of the index. Any given book of his library
can thus be called up and consulted with far greater facility than if it were taken from a shelf. As he has
several projection positions, he can leave one item in position while he calls up another. He can add
marginal notes and comments, taking advantage of one possible type of dry photography, and it could
even be arranged so that he can do this by a stylus scheme, such as is now employed in the telautograph
seen in railroad waiting rooms, just as though he had the physical page before him.
