A crescograph is a device for measuring growth in plants. It was invented in the early 20th century by Sir Jagadish Chandra Bose, an Indian scientist.
The
Bose crescograph uses a series of clockwork gears and a smoked glass
plate to record the movement of the tip of a plant (or its roots) at
magnifications of up to 10,000.
Marks
are made on the plate at intervals of a few seconds, demonstrating how
the rate of growth varies under varying stimuli. Bose experimented
with temperature, chemicals, gasses and electricity.
A Bose inspired modern electronic Crescograph was designed and built by Randall Fontes to measure plant movement at Stanford Research Institute for which culminated in a report “Organic Biofield Sensor” by H. E. Puthoff and R. Fontes.
The
Electronic Crescograph plant movement detector is capable of
measurements as small as 1/1,000,000 of an inch. However, its normal
operating range is from 1/1000 to 1/10,000 of an inch.
The component which actually measures the movement is a differential transformer.
Its movable core is hinged between two points. A micrometer is used to
adjust and calibrate the system. It could record plant growth
magnifying a small movements such as 10,000,000 times.
