the writer intended the consecutive pages to remain connected, when
he should, at last, carry out the often planned arrangement of his
writings?

What this final arrangement was to be, Leonardo has in most cases
indicated with considerable completeness. In other cases this
authoritative clue is wanting, but the difficulties arising from
this are not insuperable; for, as the subject of the separate
paragraphs is always distinct and well defined in itself, it is
quite possible to construct a well-planned whole, out of the
scattered materials of his scientific system, and I may venture to
state that I have devoted especial care and thought to the due
execution of this responsible task.

The beginning of Leonardo's literary labours dates from about his
thirty-seventh year, and he seems to have carried them on without
any serious interruption till his death. Thus the Manuscripts that
remain represent a period of about thirty years. Within this space
of time his handwriting altered so little that it is impossible to
judge from it of the date of any particular text. The exact dates,
indeed, can only be assigned to certain note-books in which the year
is incidentally indicated, and in which the order of the leaves has
not been altered since Leonardo used them. The assistance these
afford for a chronological arrangement of the Manuscripts is
generally self evident. By this clue I have assigned to the original
Manuscripts now scattered through England, Italy and France, the
order of their production, as in many matters of detail it is highly
important to be able to verify the time and place at which certain
observations were made and registered. For this purpose the
Bibliography of the Manuscripts given at the end of Vol. II, may be