ISEN-ASTC-L is a service of the Association of Science-Technology Centers Incorporated, a worldwide network of science museums and related institutions. ***************************************************************************** We are redesigning a keystone arch activity that many of you are probably familiar with. Children build a keystone arch out of five blocks that they then can walk over. We had it made once, and the blocks, although nice and met most of our criteria were to soft and compress when a child of around 50 pounds sits on them. I am looking for other materials that will be lightweight enough for small children to handle, soft enough to not knock someone out when they sail across a room, yet sturdy enough to work under compression. Any suggestions would be helpful. Thanks -- Chris Sancomb Exhibit Designer Providence Children's Museum 100 South St, Providence, RI 02903 [log in to unmask] http://www.childrenmuseum.org Come Play, Come Learn! *********************************************************************** More information about the Informal Science Education Network and the Association of Science-Technology Centers may be found at http://www.astc.org. To remove your e-mail address from the ISEN-ASTC-L list, send the message SIGNOFF ISEN-ASTC-L in the BODY of a message to [log in to unmask]