Crescograph
A crescograph is a device for measuring growth in plants. It was invented in the early 20th century by Sir Jagadish Chandra Bose - a Bengali polymath, physicist, biologist, botanist, archaeologist.
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, gases, and electricity.<[1]
A Bose-inspired modern electronic Crescograph [2] was designed and built by Randall Fontes to measure plant movement at Stanford Research Institute for (S.R.I Project 3194 (Task 3) November 1975), which culminated in a report.[3]
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 movement as much as 10,000,000 times.
References
- ↑ "Jagadis Bose Research on Measurement of Plant Growth (reproductions of Bose Research Institute books from the Hanscom AFB Geophysical Research Library)". Retrieved April 27, 2007.
- ↑ Modern Electronic Crescograph
- ↑ H. E. Puthoff and Randall Fontes. "Organic Biofield Sensor, Electronics and Bioengineering Laboratory S.R.I Project 3194 (Task 3) November 1975".