Nicholas Callan and experimental philosophy under Dr. Cornelius Denvir. He introduced the experimental method into his teaching, and had an interest in electricity and magnetism. Callan was ordained a priest in 1823 and went to Rome to study at Sapienza University, obtaining a doctorate in divinity in 1826. While in Rome he became acquainted with the work of the pioneers in electricity such as Luigi Galvani (1737–1798) who was a pioneer in modern obstetrics and Alessandro Volta (1745–1827) who is known especially for the development of the electric battery. In 1826, Callan returned to Maynooth as the new Professor of Natural Philosophy
Volta potential electrostatic potentials, but instead the difference in Fermi level between the two materials, a difference that is exactly zero at equilibrium. The Volta potential however corresponds to a real electric field in the spaces between and around the two metal objects, a field generated by the accumulation of charges at their surfaces. The total charge formula_2 over each objects' surface depends on the capacitance formula_3 between the two objects, by the relation formula_4 where formula_5 is the Volta potential. It follows therefore that the value of the potential can be measured by varying the capacitance between the materials by a