Robin,
Thanks for the reference to Huggins’ publication. His description of his equipment and his early visual spectroscopic observations is fascinating. His efforts to reliably calibrate his spectra are positively heroic. You get a real sense of his excitement in discovering the nature of the objects he was observing spectroscopically for the first time. He was one of the first to attempt to classify spectra in a systematic way. You can also sense his competitiveness in promoting his discoveries. It’s a great read.
David