paper barometry
*
detail, title page (90º ccw; inverted)
The Practical Druggist and Pharmaceutical Review of Reviews 33 (January-December 1915)
Ohio State University copy, digitized March 11, 2014
in which — Notes and Queries (May 1915) — a recipe for a paper barometer yields these indications —
Rose-red rain
Pale-red very moist
Bluish-red moist
Lavender-blue nearly dry
Blue very dry
tags:
barometer; purple rain; rounds