- Introduction to the astrolabe.astrolabes.org/astrolab.htm
- Caltech Astronomy ...www.astro.caltech.edu/observatories/palomar/history
- Churches as scientific instruments by J. L. Heilbron Annual Invitation Lecture to the Scientific Instrument Society, Royal Institution, London, 6 December 1995 During the 17th and 18th centuries cathedrals in Bologna, Rome, Florence, and Paris served as centers of astronomical investigation - or, to speak in our overheated language - as state-of-the-art, world-class, solar observatories. Solar ...cis.alma.unibo.it/NewsLetter/090496Nw/Heilbron.htm