Henry’s study

In May 1842, Henry started a series of experiments about magnetization, secondary and tertiary current induced by static discharge and oscillatory discharge. In this period, he made some important discoveries including the first detection of radio wave. The following list includes his major writings and experiment records.

1. Oct. 9th, 1841. In this account, Henry first mentioned the “magnetometer” and the way to use needles for measurement, which were the main method used in his following experiments. Some description of batteries were also included.

Oct. 9th 1841
2. May 6th, 1842. Henry started to do a month-and-a-half period of experiments about magnetization, secondary current and oscillatory discharge.

May 6th, 1842
3. May 31st, 1842. Henry started experiments attempting to confirm Savary’s finding(changing of polarity). The experiments on this subject lasted until he gave his presentation to the American Philosophical Society.

May 31st, 1842
4. June 17th, 1842. Henry gave an oral presentation to the American Philosophical Society, “Contributions V: Induction form Ordinary Electricity; Oscillatory Discharge” which summarized most of his work in the previous period.

June 17th 1842
5. Nov. 3rd 1843. This short article explained a little more about his previous presentation to the American Philosophical Society about Oscillatory Discharge at the “Theory of the discharge of the Leyden Jar” section.

Nov 3rd 1843
6. Nov 7th 1845. “Experiments on Electrical Discharge” to American Philosophical Society. Henry mentioned some phenomenon of his previous experiments in the 4th paragraph.

Nov 7th 1845
7. Aug. 24th, 1850, Henry’s short article to American Philosophical Society mentioned his old experiments about discharge of Leyden jar.

Aug 24th 1850