Question

What year was Hans and Zacharias Janssen born?

Answer 1

Since this is not my area of expertise, I searched Google under the key words "<I>Hans Zacharias Janssen</I>" to get these possible sources:

http://en.wikipedia.org/wiki/Zacharias_Janssen
(Broken Link Removed)
http://www.amazines.com/Hans_Janssen_related.html
http://www.amazines.com/Hans_Janssen_related.html

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.