Lorenzo Niles Fowler compiled this notebook of phrenological readings for individuals encountered during his travels through upstate New York, western Pennsylvania, Ohio, Indiana, and Kentucky in 1834 and 1835. There are a number of examinations of lunatics, prisoners, and criminals, including this assessment of G. H. Clark of Ithaca, who was accursed of murdering his wife.
Fowler said that G. H. Clark "was notoriously wicked, cruel and profligate. Had but little or no real tender feelings. In a rage he cut his wife to pieces in the street, and from that day to the day of his death he showed no more sorrow or sense of wrong than a brute."
The Fowler brothers used The Illustrated Self-Instructor as both a popular handbook to phrenology and an advertising tool—the opening pages of each volume were used to record character assessments, such as this one for G. A. Hook, given by O. S. Fowler in 1854. Individual faculties were rated on a scale of 1 to 7; traits on the lower end were ripe for development while those on the higher end could be repressed.
The Illustrated Self-Instructor went through over twenty editions, the last appearing in 1918. In 1895, L. N. Fowler asserted that over 100,000 copies of the work had been sold.
The variety of subjects allied to phrenology under the Fowler brothers is illustrated by this volume of their popular periodical, The American Phrenological Journal and Miscellany. In addition to biographical sketches of prominent individuals, cranial analyses, and news of the progress of the movement, the Journal printed items such as "Time in a Calf," discussing the phrenological faculties in that animal, and these "Verses Inscribed by a Phrenologist on a Skull."
Marked or numbered with the thirty-five faculties identified by J. G. Spurzheim, these 19th century symbolical heads remain the most enduring icon of the phrenological movement. Many heads of this type were produced and marketed by the Fowler and Wells company as both teaching tool and advertising.
Lorenzo N. Fowler said of the symbolical head, "For thirty years I have studied Crania and living heads from all parts of the world, and have found in every instance that there is a perfect correspondence between the conformation of the healthy skull of an individual and his known characteristics. To make my observations available I have prepared a Bust of superior form and marked with the divisions of the Organs in accordance with my researches and varied experience."
This portrait of Lorenzo Niles Fowler is inscribed on the verso of the title page of Phrenological Dictionary. This short guide to phrenology, by Lorenzo Niles Fowler and his daughter, defines the various faculties and concludes with an essay describing the procedure for finding certain organs on the surface of the skull. "Let us take, then, for our starting point the outer angle of the eye, and draw a line to the middle of the top of the ears, and Destructiveness is exactly under this point, and extends upward about half an inch above the top of the ears.... When Secretiveness is small and Destructiveness is large, there will be a horizontal ridge extending forward and backward, more or less prominent, according to the size of this organ."