Interesting.........
Although, I had never heard of harmonographs until I saw this text in a book store recently, the drawing on the cover caught my eye immediately, as I had seen similiar drawings, created by some drawing device using pendulums, in Annie Besant and Charles Leadbeater's THOUGHT FORMS, first published over 100 years ago. Those who are familiar with Stephen Phillips' 1980 work: Extrasensory Perception of Quarks (which is a contempory analysis of Besant & Leadbeater's Occult Chemistry, published in 1908 & 1919) might be well inclined to take Besant and Leadbeater seriously regarding their geometric descriptions of thought forms. Since Besant and Leadbeater assume that there is some commonality between the shape of the thought forms they perceived and those drawn by a harmonograph, this book seems like a good introduction to this long forgotten device, which may provide some sort of conceptual framework to think about thought forms.