Probably there was nothing whatever to prevent the development of illuminated graph charts long before the days of William Playfair except lack of reliable factual data from which to make the charts. People of those days must have found out, just as we find out so often now, that if we start to chart our facts, we are frequently stopped by the startling insufficiency of the data, the annoyance that the data may have a single gap in its continuity, or that the data have not been kept on a uniform basis over the period of time under consideration.

Organization of data on a rectangular field would appear to be so obvious that it might have been done fairly early by scholars in different countries, if they had had much data to study. The printed page with its lines of words proceeding from left to right is in itself a coordinate field, the lay-out of which required careful thought from those who produced the illuminated manuscripts or books which are so fascinating to us now. Descartes in 1637 published his works on geometry which firmly established the method of rectangular coordinates when used for mathematical formulas. Those who are interested in the history of graphic presentation will find the sequences well brought out in a paper of one hundred and thirtyfive pages by H. Gray Funkhouser, published in Osiris, Volume Three, Part One, 1937, available through the Carnegie Institution of Washington, D. C. Funkhouser dates the use of the coordinate field to astronomers and surveyors as far back as 140