huge assortment of all original and intact american early 1960's vintage science classroom "molecular model" sets designed and fabricated by the sargent-welch scientific company, buffalo, ny. the large assortment of parts were used in chicago public school classrooms as teaching aids representing the basic principles of atomic structure and bonding. the brightly-colored hand-painted solid wood spheres or "orbs" represent core elements including hydrogen, carbon, oxygen, nitrogen, chlorine and sulfur. each wooden ball contains pre-drilled holes for inserting wood pegs and/or coiled steel springs representing chemical bonds. priced for the collection of parts and storage box. the sargent-welch company has been in business for over 150 years. ezekiel h. sargent founded the company to sell assaying equipment in chicago in the gold-rush era. w.m. welch incorporated the w.m. welch manufacturing company in chicago in 1906. in 1968, e. h. sargent company and the welch scientific company merged to become sargent-welch scientific company.