MarcC has just pointed out an online text that will be of interest to some members. English extracts from Harmonies of the World
by Johannes Kepler tr. by Charles Glenn Wallis in 1939.

I've added it to the list of astrology texts on the web at www.skyscript.co.uk/texts.html or go straight to the page on the 'Sacred Texts site' at http://www.sacred-texts.com/astro/how/index.htm