The Introduction to IEC 62368-1 Fourth Edition Standard with UL Solutions

With some warmer temperatures and rain expected by the end of this weekend, sometimes an interesting phenomenom is witnessed at the Bunker Hill Monument. As the granite of the monument retains the cold, a warm vapor cloud, resembling mist, forms in front of the entrance door. Although the video does not quite do it justice, it is always a ghostly look. #BunkerHillMonument | Boston National Historical Park

When the Bunker Hill Monument was completed in 1843, thousands of people flocked to visit. In the 180 years since then, more additions and alterations have been made to the monument and the historic battlefield surrounding it. Learn more about these changes, culminating in the establishment of Boston National Historical Park, in the second part of our two-part video series "The Grandest Monument in the World." For a fully audio described version of this video, please go to https://www.nps.gov/me