Sunday, October 12, 2008

150th Anniversary of Albert Henry Munsell’s Year of Birth

by Rolf G. Kuehni

[This issue we have the privilege of a column from Rolf G. Kuehni, author of many books on color order and on color technology (the latest two published in 2008, one of them reviewed in this issue). I believe Rolf’s topic is a sesquicentennial. - MHB]

The year 2008 should not pass without those of us in the color world remembering that 150 years ago A. H. Munsell (1858-1918) was born. Munsell was an artist, educator, and inventor, with five patents to his name. His color order system has proved to be enormously influential if, like all such efforts, less than perfect.

Born in Boston into comfortable circumstances, Munsell showed early interest in art as well as science related to art. In 1879, at age 21, he studied the newly published book by O. N. Rood, “Modern Chromatics,” a book that became important to French postimpressionist artists. In the later 1880s he spent time in Paris, studying painting and the color order systems of people like Chevreul. Toward the end of the 19th century Munsell was employed as art instructor at the Massachusetts Normal Art School. Belonging to Boston’s high society, he was widely acquainted with people in the arts and the region’s academic establishments. All this proved helpful when he decided to develop a systematic means of teaching color order to his students. His initial idea was to use a “balanced” form of Runge’s color sphere. When rapidly rotating the sphere, the colors on horizontal planes were to add up to neutral grays of various lightness levels. He already had twirled a multicolored double pyramid in 1878, observing the phenomenon. For this idea he obtained in 1900 his second patent. Munsell realized the importance of objectively defining the color chips he prepared and in the same year invented a visual photometer, the ‘Lumenometer,’ patented in 1901.

The sphere implies three dimensions and after much thinking and discussion Munsell settled on hue, value (lightness), and chroma, the last a concept that his physicist friends had to become used to. Working with “aniline colors,” he realized that different colorants have different maximal chroma levels and as a result the solid of his ordering system would have to be of irregular shape, a shape he came to call “Munsell tree.” Much thought was given to the system’s final design.

As his “Color Diaries” show, Munsell had numerous discussions with many academics on the subject of color order. In 1905 Wilhelm Ostwald visited him and declared his interest in the new approach. A patent for his version of a color chart was applied for and granted in June 1906, with (at the time) a division of the hue circle into seven categories.
Fig. 1 Basic design of the color chart from U. S. Patent 824,374 of 1906.

In 1906 Munsell got to think about the relationship of his psychological order system to a psychophysical one. As usual, he spent the summer in Europe and returned in September on the ‘Arquette’ from Antwerp to Boston. At the Captain’s Table he met several academics, among them “Dr. & Mrs. Franklin” (Christine Ladd-Franklin, famed psychologist, mathematician, and color scientist). They had extended discussions on the ship and during her visit to his office. She introduced him to König’s early version of the chromaticity diagram (Fig. 2) and encouraged him to consider the relationship between that and his own color order system.
Fig. 2 Tracing of Munsell’s sketch of König’s chromaticity diagram, Color Diary, page 232.

In 1907 the first version with eight charts of the ‘Atlas of the Color Solid’ of the Munsell Color System was published, and the second edition in 1915 had grown to 15 charts. In 1918, the year of Munsell’s death, the Munsell Color Company was founded and the rest, as they say, is history. Munsell’s landscapes and portraits are curiosities today; his color order system is a lasting contribution to our understanding of the world of color.