Project Blue Book case file: Kenneth Arnold

Read from the scan by GLM-OCR; expect the odd misread word.

Galley 16-THE WORLD OF FLYING SAUCERS

Figure 3. Mirage of mountain peaks. Top, normal view of mountain chain; bottom, mirage in which some of the peaks seem to be detached and above the peaks, like saucers.

peaks of the mountains seemed to float above the mountain chain [25]. An alternative and at least equally probable explanation is that he observed orographic clouds, a type unique to mountainous country, which often appear to stand more or less motionless and can assume dramatic shapes. "Grindstone" clouds, shaped like the thick, solid disks they are named for, are common phenomena in the valleys just east of the Sierra Nevada in California and in the mountainous regions of Washington, Colorado, and New Mexico—areas where flying-saucer reports have tended to concentrate [26a]. One of the most spectacular types of mountain cloud, they closely resemble the "pile d'assiettes" or "stack of plates" formation in which the cloud assumes a flat, round shape like a plate or a saucer, and two or more are piled together in a neat stack like a layer cake. A beautiful picture of a "stack of plates" (which some observers reported as a hovering flying saucer) was made on May 31, 1953, near Jindabyna, Snowy Mountains, New South Wales, and reproduced in Weather in November 1954 (Plate 47). The cloud formed over a tub churned depression in the mountains and remained at