At the Morgan Library through May 30th: one of the earliest engrossments of the Magna Carta from 1217.
That is to say, it isn't what was signed at Runnymede, but it is an original legal document because it bears the royal seal.
It is written in the strikingly small, fair chancery hand of an era when parchment was bloody expensive and labor was cheap. Let us give thanks to the papermakers, who over the centuries of development of their craft changed our lives so much for the better!
By 1217 John was dead, so his son's name is at the top of the page, because the rule of law will outlive a man, if you do it right.
Also at the Morgan, a choice collection of images by Durer, through September 12th. Durer's virile and expressive pen strokes are also worth seeing in person.
At the Met, conservation of the currently unbound Belles Heures gives a rare opportunity to see all of its illuminated pages as individual leaves. The Met provides magnifying glasses to better appreciate the splendor of the work in person. You can appreciate the life that minute decorative punchwork brings to gold leaf backgrounds,or gold and silver highlights on the surface of a troubled sea. This is well worth seeing in person, if you can, before the manuscript is rebound. The exhibition runs through June 13th, 2010.
I write this on the last day of The Mourners: Medieval Tomb Sculptures from the Court of Burgundy. Fortunately, the web site still contains a wealth of useful images.