In addition to this, he was the inventor of many marvellous contrivances for the demonstration and measurement of the more obscure physical forces.

His official position was that of Lecturer and Demonstrator in Physical Science in Harvard University.
He and Professor Marmion had been deadly opponents in the field of controversy for years.

The latter had once detected an error in a very learned monograph which he had published in the _Scientific American_ on the "Co-Relation of the Etheric Forces in the Phenomena of Light and Heat," and of course he had never forgiven him.

From that day forth a relentless duel of wits between them had continued.

Every essay, monograph, or book that the one published, the other criticised with cold but ruthless severity, to the great delectation of the scientific world, if not to the clarification of its atmosphere.
Socially, they were cordial acquaintances, if not friends.