Thanks for the comments, guys.
Yes, it's like having a candy factory close to home. I expect to make more visits in different kinds of weather. The black-and-whites are my favorites, too.
It also has free admission, and lots of fascinating information about the history of water and reservoirs for the Boston area. Boston and most local suburbs get their water from Quabbin Reservoir in the middle of the state. It was built in the 1930s by flooding four towns, sort of like Massachusetts' own "Hetch Hetchy."
The volunteer guides at the museum are all quite helpful and well-informed, and they will leave you alone to photograph or give you private tours as you wish.
Eric