Abstract :
The papers unearthed dealt mainly with problems connected with the flow of electromagnetic energy, and showed that Heaviside had extended Maxwell´s theory so that gravitation could be fitted in with electromagnetism. It was also found that Heaviside had evolved a rigorous justification for his `operation¿ of extracting the square root of the process of partial differentiation; for he had discovered the conditions under which his differential time operator p lost its original significance and became the transform parameter of an infinite integral of the Stieltjes type which obeys all the laws of algebra and analysis.
