Alexander S.C. and Holton Rower sold a co-op at 139 Chambers St. in Tribeca to Gary Rapp for $2.525 million on July 10.

Unit #10 is part of a 10-story building that was constructed in 1915.

Alexander Rower is the founder, chairman and director of the Calder Foundation, which runs programs and exhibitions of the work by artist Alexander Calder, Alexander Rower's grandfather.

Calder was a sculptor and artist who is most famous for inventing the mobile. He worked a great deal with wire and created kinetic and stable art, and also created paintings, lithographs and toys. He passed away in 1976.

Holton Rower is an artist living with his family in New York. He also is a grandson of Calder.

Condo sales in Tribeca increased 125 percent from 2006-2007, rising from 215 to 483. The median sales price dropped in the same period by 7 percent, however, falling from $1.9 million to $1.8 million.

Address: 139 Chambers Street, Unit: 10
Buyer(s): Rapp and Gary
Seller(s): Rower, Alexander S C, Rower and Holton
Sale date: Jul. 10, 2008