Who was Pierre Janssen?

On 22 Feb 1824, Pierre Janssen was born. And standard biographies will tell you of his work with the solar spectrum, yada, yada, etc. ... But they don't tell you this... So, you've got this astronomer, who's been lame since early childhood, pushing 70 years of age, who decides that to know if the Earth's atmosphere changes what is seen in the solar spectrum, he must go up to where the air in thinnest - up a mountain - on Mont Blanc! With his infirmity, he had to get there in a sedan chair made using a ladder carried by a team of porters. Liked what he saw up there, so he decided he needed an observatory built there. He made the next trip up in a sled pulled by a team of porters. And yes, he did have an observatory built a few feet below the summit of Mont Blanc. In snow so deep there was no bed-rock to rest the structure on. Ready to read more? Try this article from 1894: The Observatory On Top Of Mont Blanc. You'll find out more about Pierre Janssen's adventurous life in the pursuit of scientific knowledge. Astonishing!