Presented to the American Philosophical Society between 1835 and 1842, the five volumes of Joseph Henry’s “Contributions to Electricity and Magnetism” represent the majority of his work in the early field of electricity and magnetism during his time at Princeton University.
Contributions #1 details and explains a Galvanic battery constructed by Henry for demonstrative and experimental use. This battery was composed of a series of copper and zinc cells that could be linked in different manners to affect the battery’s total voltage or longevity. In the paper, Henry provides highly detailed descriptions and drawings which hint at his desire to spread scientific and practical knowledge.
“Contributions #2” deals with effect of a spiral conductor or a coil of wire on the intensity of electricity as shown through a spark. It details the experiments the done that led up to his findings. It also must be noted that Henry acknowledges Faraday’s publication on the same topic several months before Henry’s. This sets up a competition of sorts between the two men as they both study and publish on the same line of research for several years to come.
“Contributions #3” deals with electric-dynamic induction, and is probably the most important of Henry’s “Contributions.” Henry’s experiments that led up to this paper involved large coils that can be seen in the “Coils and Helices” tab. Using these coils with Leyden Jars, he was able to induce a secondary current in an adjacent wire. He also expanded the experiments to include higher order currents and induction at a distance, through walls, and eventually across Nassau Hall.
In “Contributions #4,” Joseph Henry reexamines and expands upon his conclusions made in “Contributions #3” which he admits may have been rushed to publication. This hints at the possible competition between Henry and Faraday.
Contributions #5 was presented before the American Philosophical Society in 1842. Unfortunately, a copy of the original transcript of Henry’s address no longer exists. What is generally regarded as Contributions #5 is a firsthand summery of Henry’s presentation. Contributions #5 deals with induction from “ordinary” electricity and oscillatory discharge.
Special thanks and recognition goes out to JSTOR, the American Philosophical Society, and others who helped maintain the historical record and create digital copies of these works.