Student and Schoolmate
This article is a great little find, I think I am the first to come across it.
Though the gestures it illustrates may not be the same ones Chamberlain used when giving this speech,
it does show how Chamberlain as professor of rhetoric and oratory would instruct his students in the use of hand gestures in public speaking.
This book published in 1866 uses a portion of Chamberlain's speech that was read at the Dedication of the Soldiers' Monument Gorham, Maine
Before heading off to war Professor Chamberlain joked about these gestures at a war rally.
Appealing "to the young men in his audience, many of whom he had instructed in rhetoric,
he would say, 'The only gesture you have to learn now is, down in front,' indicating a sabre-thrust."*