X-rays and their uses. X-rays are one type of electromagnetic radiation. They are commonly used in hospitals to produce photographs of bones which can be checked for breaks or fractures. X-rays have the following properties: they can penetrate less dense matter such as skin and body tissue (but not bone)
The historic Glensheen Mansion, along London Road in Duluth MN, was built for Chester Congdon and his family. Chester Congdon went from being a school teacher in Wisconsin to being the wealthiest Minnesotan at the time of his death in 1916, worth 40 million dollars.
The mansion cost $11 million ($260,000,000 in 2009 dollars) of which $7 million was spent on 500,000 cubic feet (14,000 mÂ³) of marble. Vanderbilt's older brother Cornelius Vanderbilt II subsequently built the largest of the Newport cottages, The Breakers, between 1893 and 1895.