Fisher Scientific is always a good source for supplies. You can get a variety of lenses for $3.20 each at: http://www.fisheredu.com/cgi-bin/catalog.cgi?item=p0491 >>I'm developing a weekend workshop in which >>children will build working telescopes. Can >>anyone suggest a good supplier of convex and >>concave lenses? ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).